essay on soil uses

Why are soils important?

Soil is our life support system. Soils anchor roots, hold water and store nutrients. Soils are home to earthworms, termites and a myriad of micro-organisms that fix nitrogen and decompose organic matter. We build on soil as well as with it.

Soil plays a vital role in the Earth’s ecosystem and without soil, human life would be very difficult.

Soil provides plants a foothold for their roots and holds the necessary nutrients for plants to grow. Soil filters the rainwater and regulates the discharge of excess rainwater, preventing flooding.  It also buffers against pollutants, thus protecting groundwater quality.

Soil is capable of storing large amounts of organic carbon. It is the largest terrestrial store of carbon. On average, the soil contains about three times more organic carbon than the vegetation and about twice as much carbon than is present in the atmosphere [ source ]. This is of particular importance in efforts to mitigate climate change. Carbon can come out of the atmosphere and be stored in the soil, helping to re-balance the global carbon budget.

Soil provides people with some essential construction and manufacturing materials: we build our houses with bricks made from clay and we drink coffee from mugs that are essentially baked soil (clay). Water is served in a glass made from sand (silicon dioxide).

Rocks and minerals come to mind as the basis of soil material, however the soil also hosts a great deal of living organisms. The biodiversity of visible and microscopic life which uses the soil as their home is vast. The soil is one of the planet’s great reservoirs of undiscovered microorganisms and therefore genetic material which can become the basis of other scientific research such as developing new medicines.

Soil is also an archive. It presents a record of past environmental conditions by storing natural artifacts from past ecosystems like pollen. Many artifacts from human history are also stored underground, which archeologists carefully uncover and use to understand how civilizations have evolved.

Soil functions are general soil capabilities that are important for many areas of life including agriculture, environmental management, nature protection, landscape architecture and urban applications. Six key soil functions are:

• Food and other biomass production
• Environmental Interaction: storage, filtering, and transformation
• Biological habitat and gene pool
• Source of raw materials
• Physical and cultural heritage
• Platform for man-made structures: buildings, highways

• ENVIRONMENT

Why soil matters (and what we can do to save it)

Soil is failing across the world: every five seconds a soccer pitch of soil is eroded, and it’s estimated that by 2050 around 90 percent of the Earth’s soils could be degraded. What does this mean for people and planet, and what can we do to restore a healthy balance to the soil we need to survive?

A worm burrows its way through the dark earth, ingesting particles of soil and expelling nutrient-rich casts in a constant forage for food. Charles Darwin described earthworms as one of the most important creatures on Earth. Worms are critical to soil health, and without soil Planet Earth would be little more than a lifeless rock. So why is it that most of us take the earth beneath our feet for granted?

We might imagine soil as endless and indestructible: it is neither. Only about 7.5 percent of the earth’s surface provides the soil we rely on for agriculture, and it is remarkably fragile. Topsoil is used to grow 95 percent of our food, and it is disappearing ten times faster than it is being replaced: America’s corn belt has already lost much of its topsoil, threatening livelihoods and communities as well as food supply. The reality is that it takes thousands of years to create an inch of fertile topsoil, but it can be destroyed in minutes.

Healthy soil is a dynamic living ecosystem: a complex combination of minerals and organic matter containing air, water, and life. Worms are not alone in the ground, just a gram of dirt can contain as many as 50,000 species, all interacting with each other to keep their soil habitat healthy and productive. The activity of these organisms, the type of rock particles, the volume of organic matter, and the proportion of air and water all combine to create hundreds of different types of soil. These range from loose sandy soils to waterlogged peats to the beautifully balanced loam that is so well suited to agriculture. But human activity is destroying the balance and one-third of the world’s soil is already degraded.

Soil degradation, where soil loses the physical, chemical, or biological qualities that support life, is a natural process but it is being accelerated by human activity. Pollution kills microbial life in the soil; deforestation and development disturb soil structure making it vulnerable to erosion; soil compaction associated with farming and urbanization squeezes the air out of the ground and prevents it from absorbing water. Meanwhile, climate change continues to dry the ground: three-quarters of Spain is at risk of becoming desert.

But perhaps the biggest threat to soil is intensive farming. The need to feed a growing population and drive greater efficiency has sacrificed natural balance for increased yields. Monoculture farming, where one crop is grown repeatedly on the same ground, drains the soil of specific nutrients and allows pests, pathogens, and diseases to thrive. The pesticides and fertilizers used to counter these problems come with significant drawbacks. Excessive use of pesticides reduces vital biodiversity; the addition of nitrogen fertilizer speeds up the breakdown of organic matter, starving the soil’s microbial populations.

Even the plow, often considered one of history’s great inventions, can be bad news for soil. Tilling breaks up compacted ground, controls weeds, and incorporates organic matter, but we now understand how it also damages soil structure, dries out topsoil, and accelerates erosion. Similarly, the age-old practice of irrigation, when overdone, increases the volume of salt in the soil, damaging its biodiversity, water quality, and productivity. As a result of such destructive practices, in Europe alone, around 70 percent of the soil is considered unhealthy.

This matters, because without soil we cannot survive. Healthy soil is the root source of a livelihood that sustains farmers and communities all around the world: good soil produces good crops that deliver a good income that enables families to flourish. But it’s more than this. Soil filters the water we drink, grows the food we eat, and captures the carbon dioxide that causes climate change. Soil is the largest carbon sink after the ocean and holds more carbon than all terrestrial plant life on the planet. But when we damage the soil, water systems become disrupted, food production declines, and carbon is released into the atmosphere. Any one of these essential soil functions would be reason enough to preserve our soil: taken together they are a compelling argument for urgent action.

So, how can we save our soils? Many of the ways to reduce and even reverse the damage are reliant on changes to current agricultural practices. By not tilling the land and reducing our reliance on pesticides and fertilizers, soil starts to recover. Replacing our reliance on monoculture with a return to crop rotations gives soil time to replenish the nutrients needed by plants. Agroforestry could take this further, growing a variety of plants together in ways that their biological systems support each other and help soil to flourish. Similarly, promoting soil fungi helps plants extract nutrients from the soil while increasing resistance to disease and building healthy soil structure. These good practices could regenerate our soils which helps sustain livelihoods and local communities, and keep people and planet healthy: but they require big changes.

Inspiring a fundamental shift in the way we farm needs to be driven by both the consumer and the companies they buy from. Responsible companies, including Unilever, are making serious commitments to minimize the damage done to the soil, while actively working to regenerate degraded land. This includes encouraging and supporting suppliers to improve soil health through regenerative practices such as growing cover crops that protect and nourish the soil between harvests: in Iowa, a state that has lost half its topsoil in a hundred years, farmers using cover crops reported that their land weathered heavy spring winter rains better than their neighbors’ land.

Knorr, Unilever’s largest food brand, is looking to expand such practices. It has set a goal of growing 80 percent of its key ingredients following Unilever’s Regenerative Agriculture Principles by 2026. Already, Knorr has partnered with Spanish tomato growers to use cover crops to improve soil health and reduce the use and impact of synthetic fertilizers; in the US Knorr is working with its suppliers to grow rice in ways that will reduce its demand for water and cut methane emissions. These are two of the many ongoing and planned projects as Knorr expands and scales up such projects while sharing their knowledge and inspiring others to transform the way food is grown.

Soil needs all the help it can get. It is a priceless, irreplaceable resource and key to sustaining all life on earth. Soil is struggling for survival but there is still time to rebuild our soils as healthy, productive, sustainable ecosystems. As the world learns to work together to preserve our oceans, our forests, and our biodiversity, we now need to look to the ground. The humble earthworm can only do so much: it’s time for individuals, communities, companies, and countries to help save our soils.

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Soil: The Foundation of Agriculture

Human society has developed through utilization of our planet's resources in amazingly unique, creative, and productive ways that have furthered human evolution and sustained global societies. Of these resources, soil and water have provided humans with the ability to produce food, through agriculture, for our sustenance. In exploring the link between soil and agriculture, this article will highlight 1) our transition from hunter-gatherer to agrarian societies; 2) the major soil properties that contribute to fertile soils; 3) the impacts of intensive agriculture on soil degradation; and 4) the basic concepts of sustainable agriculture and soil management. These topics will be discussed to demonstrate the vital role that soils play in our agriculturally-dependent society.

Agriculture and Human Society

It is clear that agriculture sustains and defines our modern lives, but it is often disruptive of natural ecosystems. This is especially true for plant communities, animal populations, soil systems, and water resources. Understanding, evaluating, and balancing detrimental and beneficial agricultural disturbances of soil and water resources are essential tasks in human efforts to sustain and improve human well-being. Such knowledge influences our emerging ethics of sustainability and responsibility to human populations and ecosystems of the future.

Although agriculture is essential for human food and the stability of complex societies, almost all of our evolution has taken place in small, mobile, kin-based social groups, such as bands and tribes (Diamond 1999, Johanson & Edgar 2006). Before we became sedentary people dependent on agriculture, we were largely dependent on wild plant and animal foods, without managing soil and water resources for food production. Our social evolution has accelerated since the Agricultural Revolution and taken place synergistically with human biological evolution, as we have become dependent on domesticated plants and animals grown purposefully in highly managed, soil-water systems.

Soil Fertility and Crop Growth

The early use of fire to flush out wild game and to clear forested land provided the first major anthropogenic influence on the environment. By burning native vegetation, early humans were able to gain access to herbivores grazing on the savanna and in nearby woodlands, and to suppress the growth of less desirable plant species for those easier to forage and eat (Pyne 2001, Wrangham 2009). These and other factors (e.g., population pressures, climate change, encouraging/protecting desirable plants), help to lay the groundwork for the Agricultural Revolution and caused a dramatic shift in the interactions between humans and the earth. The shift from hunter-gatherer societies to an agrarian way of life drastically changed the course of human history and irreversibly altered natural nutrient cycling within soils. When humans sowed the first crop seeds at the dawn of the Neolithic Period , the soil provided plant-essential nutrients and served as the foundation for human agriculture.

Plant Nutrients

Throughout Earth's history, natural cycling of nutrients has occurred from the soil to plants and animals, and then back to the soil, primarily through decomposition of biomass. This cycling helps to maintain the essential nutrients required for plant growth in the soil. Complex nutrient cycles incorporate a range of physical, chemical, and — most importantly — biological processes to trace the fate of specific plant nutrients (e.g., N, P, C, S) in the environment. For a thorough analysis of these cycles, additional reference materials are available (Bernhard 2010, Brady & Weil 2008, Troeh & Thompson 1993). For the purpose of this article, a simplified version of nutrient cycling in natural and agricultural systems is shown in Figure 1.

It is generally accepted that there are 17 essential elements required for plant growth (Troeh & Thompson 1993). The lack of any one of these essential nutrients, listed in Table 1, can result in a severe limitation of crop yield — an example of the principle of limiting factors. Of the mineral elements, the primary macronutrients (N, P, and K) are needed in the greatest quantities from the soil and are the plant nutrients most likely to be in short supply in agricultural soils. Secondary macronutrients are needed in smaller quantities, are typically in sufficient quantities in soil, and therefore are not often limiting for crop growth. The micronutrients, or sometimes called trace nutrients, are needed in very small amounts and, if in excess, can be toxic to plants. Silicon (Si) and sodium (Na) are sometimes considered to be essential plant nutrients, but due to their ubiquitous presence in soils they are never in short supply (Epstein 1994, Subbarao et al. 2003).

Agriculture alters the natural cycling of nutrients in soil. Intensive cultivation and harvesting of crops for human or animal consumption can effectively mine the soil of plant nutrients. In order to maintain soil fertility for sufficient crop yields, soil amendments are typically required. Early humans soon learned to amend their fields with animal manure, charcoal, ash, and lime (CaCO 3 ) to improve soil fertility. Today, farmers add numerous soil amendments to enhance soil fertility, including inorganic chemical fertilizers and organic sources of nutrients, such as manure or compost, often resulting in surplus quantities of primary macronutrients. The efficiency of fertilizer application and use by crops is not always optimized, and excess nutrients, especially N and P, can be transported via surface runoff or leaching from agricultural fields and pollute surface- and groundwater (Moss 2008, Sharpley et al. 2002).

Soils for Agriculture

While soil is frequently referred to as the "fertile substrate", not all soils are suitable for growing crops. Ideal soils for agriculture are balanced in contributions from mineral components (sand: 0.05–2 mm, silt: 0.002–0.05 mm, clay: soil organic matter (SOM), air, and water. The balanced contributions of these components allow for water retention and drainage, oxygen in the root zone, nutrients to facilitate crop growth; and they provide physical support for plants. The distribution of these soil components in a particular soil is influenced by the five factors of soil formation: parent material, time, climate, organisms, and topography (Jenny 1941). Each one of these factors plays a direct and overlapping role in influencing the suitability of a soil for agriculture.

Inorganic Soil Components

The mineral components of soil may exist as discrete particles, but are more commonly associated with one another in larger aggregates that provide structure to soil. These aggregates, or peds , play an important role in influencing the movement of water and air through soil. Sandy soils have large pore spaces and increase water drainage, but do not provide soils with many nutrients. Clay-rich soils, on the other hand, increase water holding capacity and provide many plant essential nutrients. A common measure of soil fertility is obtained by measuring the cation exchange capacity (CEC). The CEC is a measure of a soil's ability to exchange positive ions between the soil particles and solution surrounding these particles.

Soil Organic Matter (SOM)

SOM comprises the partial or well-decomposed residues of organic biomass present in soil. SOM gives topsoil its deep black colors and rich aromas that many home gardeners and farmers of grassland soils are familiar with. Surface soils are composed of approximately 1 to 6% organic matter, with SOM decreasing with depth (Brady & Weil 2002). The ‘Great Plains' of North America and the ‘Bread Basket' of Europe are some of the world's most productive agricultural soils because they developed under grassland vegetation, whose root biomass and decomposition resulted in SOM accumulation. Figure 2 is a photograph of an organic matter-rich soil ( mollisol) formed under prairie vegetation in the United States. The thick dark upper layers in this soil reflect the high SOM content. The presence of SOM is crucial for fertile soil as it provides essential plant nutrients, beneficially influences soil structure , buffers soil pH , and improves water holding capacity and aeration. The presence of organic, ionizable functional groups (e.g., carboxyl, alcoholic/phenolic OH, enol, quinone, and amine) impart charge to SOM (Sparks 1995), contributing high CEC, and pH buffering capacity.

Figure 2: Mollisol soil profile showing thick dark A horizon with high organic matter content. Photo courtesy of USDA.

Often referred to as the master variable of soil, pH controls a wide range of physical, chemical, and biological processes and properties that affect soil fertility and plant growth. Soil pH, which reflects the acidity level in soil, significantly influences the availability of plant nutrients, microbial activity, and even the stability of soil aggregates. At low pH, essential plant macronutrients (i.e., N, P, K, Ca, Mg, and S) are less bioavailable than at higher pH values near 7, and certain micronutrients (i.e., Fe, Mn, Zn) tend to become more soluble and potentially toxic to plants at low pH values (5–6) (Brady & Weil 2008). Aluminum toxicity is also a common problem for crop growth at low pH ( et al. 2005). In instances where the pH is outside a desirable range, the soil pH can be altered through amendments such as lime to raise the pH. Ammonium sulfate, iron sulfate, or elemental sulfur can be added to soil to lower pH.

Soil Degradation and Crop Production

Historically, conventional agriculture has accelerated soil erosion to rates that exceed that of soil formation (Table 2). Erosion is often accelerated by agricultural practices that leave the soil without adequate plant cover and therefore exposed to raindrop splash and surface runoff or wind (Singer & Munns 2006). Throughout human history, soil erosion has affected the ability of societies to produce an adequate food supply. Poignant examples of this can be seen in the eroded silt built up in the ancient riverbeds of Mesopotamia, making irrigation problematic (Hillel 1992), and the United States Dust Bowl of the 1930s where a devastating drought increased wind erosion, carrying fertile topsoil from the Midwest hundreds of kilometers to Washington, DC (Montgomery 2007). Figure 3 is a stunning photograph demonstrating the devastating effects of this severe wind erosion. The Dust Bowl made soil erosion a high priority in the American public consciousness of the 1930s, and it remains a top priority today.

Figure 3: Dallas, South Dakota: tractor and farm equipment buried by soil transported by wind (May 13, 1936). Photo courtesy of USDA.

Today, agricultural fields are not immune to the forces of nature (e.g., moving water, blowing wind, extremes of temperature) that caused soil erosion in the past. Figure 4 shows the severe effects of surface runoff and soil loss in the northwestern United States. Implementation of agricultural best management practices (BMPs), and through the practice of conservation agriculture , the rate of soil loss can be reduced to approximately equal the rate of soil formation, although often still greater than that in natural systems (Table 2). In addition to soil erosion, intensive land use has resulted in deforestation , water shortages, and rapidly increasing desertification of vast areas of the globe, all of which threaten the sustainability of our agricultural systems.

Figure 4: Damage to agricultural field in Washington (United States) resulting from water erosion. Photo courtesy of USDA.

Sustainable Soil Management

Agricultural Revolution : The shift from hunter-gatherer to agrarian societies occurring 10,000 to 12,000 YBP. The Agricultural Revolution is a key component of the Neolithic Revolution.

aluminosilicate : Class of clay minerals found in soils which are primarily comprised of silicon, aluminum and oxygen that are assembled into sheets of silica tetrahedral and aluminum octahedral.

cation exchange capacity : Operationally defined measurement of a soil's ability to exchange positive ions between the soil particles (e.g., clay, organic matter) and solution surrounding these particles.

chemical weathering : Process by which rocks, soil, and minerals are dissolved or broken down via a range of chemical processes including carbonation, hydrolysis, hydration, and redox reactions.

colloidal : Referring to very small (approximately 1 nm to 1 µm) inorganic or organic particles which tend to remain suspended in solution. These particles are ubiquitous in soil and, due to their high surface area, are highly reactive.

conservation agriculture : An approach to farming which minimizes degradation and/or loss of natural resources while providing sufficient crop yield and economic benefit.

deforestation : The cutting and clearing of forests and other vegetation.

desertification : Conversion and degradation of land which previously supported to plant growth, in arid or semi-arid regions, to desert land. This often occurs as a result of drought, deforestation, or other human induced land use changes.

erosion : The removal of soil from the land's surface by water, wind, ice, or gravity.

essential element (plant) : Chemical elements required by plants for normal growth and reproduction.

lime : Solid material which contains carbonates, oxides, and/or hydroxides of calcium which is applied to agricultural fields to increase the soil pH (alkalinity).

mollisol : Soil order in USDA soil taxonomy, characterized by a thick organic matter enriched surface horizon, typically between 60–80 cm thick, which are commonly formed under grassland vegetation.

parent material : The geologic and organic material from which soil is formed through a variety pedogenic processes.

ped : Single unit of soil which is aggregated into granular, platy, blocky, prismatic, or columnar structure.

pH (soil) : The negative log of the hydrogen ion concentration in a soil solution which gives a measure of a soils acidity or basicity.

physical weathering : Process by which rocks, soil, and minerals a broken down into smaller particles through physical processes such as heat, water, ice, and pressure.

soil organic matter : The organic components of soil which are comprised of living microbial biomass, fresh and partially decomposed biomass (plant and animal), and the well decomposed and stable biomass fraction (humus).

soil structure : The aggregation, or secondary shape, of soil particles which adhere together into structural units (peds).

References and Recommended Reading

Alexandratos, N. World food and agriculture: Outlook for the medium and longer term. Proceedings of the National Academy of Sciences of the United States of America 96 , 5908-5914 (1999).

Bernhard, A. The Nitrogen Cycle: Processes, Players, and Human Impact. Nature Education Knowledge 2 , 12 (2010).

Bongaarts, J. Human population growth and the demographic transition. Philosophical Transactions of the Royal Society B-Biological Sciences 364 , 2985-2990, (2009) doi:10.1098/rstb.2009.0137.

Brady, N. C. & Weil, R. R. The Nature and Properties of Soil, 13th ed. Prentice Hall, 2002.

Brady, N. C. & Weil, R. R. The Nature and Properties of Soil, 14th ed. Prentice Hall, 2008.

Brodt, S., et al. Sustainable Agriculture. Nature Education Knowledge 3 (2011).

Diamond, J. Guns, Germs, and Steel: The Fate of Human Societies . Norton, 1999.

Epstein, E. The anomaly of silicon in plant biology. Proceedings of the National Academy of Sciences of the United States of America 91 , 11-17 (1994).

Harlan, J. R. Crops and Man. Am. Soc. Agron. and Soil Sci. Soc. Am., 1992.

Havlin, J. L. et al. Soil Fertility and Fertilizers . 7th ed., 2005.

Hillel, D. Out of the Earth: Civilization and the Life of the Soil . University of California Press, 1992.

Jenny, H. Factors of Soil Formation . McGraw-Hill, 1941.

Johanson, D.C., and B. Edgar. 2006. From Lucy to Language: Revised, Updated, and Expanded. Simon and Schuster, New York.

Lal, R. Soil-erosion from tropical arable lands and its control. Advances in Agronomy 37 , 183-248 (1984).

Lutz, W., Sanderson, W. & Scherbov, S. The end of world population growth. Nature 412 , 543-545 (2001).

Montgomery, D. R. Dirt: The Erosion of Civilizations . Univeristy of California Press, 2007.

Montgomery, D. R. Soil erosion and agricultural sustainability. Proceedings of the National Academy of Sciences of the United States of America 104 , 13268-13272 (2007) doi:10.1073/pnas.0611508104.

Moss, B. Water pollution by agriculture. Philosophical Transactions of the Royal Society B-Biological Sciences 363 , 659-666, doi:10.1098/rstb.2007.2176 (2008).

Pimentel, D. et al. Environmental and economic costs of soil erosion and conservation benefits. Science 267 , 1117-1123 (1995).

Pimentel, D. et al. World agriculture and soil-erosion. Bioscience 37 , 277-283 (1987).

Price, T. D. & Gebauer, A. B. Last Hunters, First Farmers: New Perspectives on the Prehistoric Transition to Agriculture . School of American Research Press (1995).

Pyne, S. Fire: A Brief History . University of Washington Press, 2001.

Schulze, D. G. in Minerals in Soil Environments , eds J.B. Dixon & S.B. Weed. Soil Science Socity of America, 1989.

Schwartz, G. M. & Nichols, J. J. After Collapse: The Regeneration of Complex Societies . The University of Arizona Press, 2006.

Sharpley, A. N., Haygarth, P. M. & Jarvis, S. C. Introduction: Agriculture as a potential source of water pollution. Agriculture, hydrology and water quality , 4-5 (2002).

Singer, M. J. & Munns, D. N. Soils: An Introduction , 6th ed. Pearson Education Inc., 2006.

Smith, B. D. The Emergence of Agriculture . Scientific American Library, 1995.

Sparks, D. L. Environmental Soil Chemistry . Academic Press, Inc., 1995.

Sposito, G. The Chemsitry of Soils , 2nd ed. Oxford University Press, 2008.

Subbarao, G. V., Ito, O., Berry, W. L. & Wheeler, R. M. Sodium - A functional plant nutrient. Critical Reviews in Plant Sciences 22 , 391-416, doi:10.1080/07352680390243495 (2003).

Tilman, D. Global environmental impacts of agricultural expansion: The need for sustainable and efficient practices. Proceedings of the National Academy of Sciences of the United States of America 96 , 5995-6000 (1999).

Tilman, D., Cassman, K. G., Matson, P. A., Naylor, R. & Polasky, S. Agricultural sustainability and intensive production practices. Nature 418 , 671-677, doi:10.1038/nature01014 (2002).

Trigger, B. G. Understanding Early Civilizations: A Comparative Study . Cambridge University Press, 2003.

Troeh, F. R. & Thompson, L. M. Soils and Soil Fertility , 5th ed. Oxford University Press, 1993.

Wakatsuki, T. & Rasyidin, A. Rates of weathering and soil formation. Geoderma 52 , 251-263 (1992).

Wrangham, R. Catching Fire: How Cooking Made us Human . Basic Books, 2009.

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Sustainable soil use and management: An interdisciplinary and systematic approach

a School of Environment, Tsinghua University, Beijing 100084, China

Nanthi S. Bolan

b Global Centre for Environmental Remediation, The University of Newcastle, Callaghan, NSW 2308, Australia

Daniel C.W. Tsang

c Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China

Mary B. Kirkham

d Department of Agronomy, Throckmorton Plant Sciences Center, Kansas State University, Manhattan, KS, United States

David O'Connor

Soil is a key component of Earth's critical zone. It provides essential services for agricultural production, plant growth, animal habitation, biodiversity, carbon sequestration and environmental quality, which are crucial for achieving the United Nations' Sustainable Development Goals (SDGs). However, soil degradation has occurred in many places throughout the world due to factors such as soil pollution, erosion, salinization, and acidification. In order to achieve the SDGs by the target date of 2030, soils may need to be used and managed in a manner that is more sustainable than is currently practiced. Here we show that research in the field of sustainable soil use and management should prioritize the multifunctional value of soil health and address interdisciplinary linkages with major issues such as biodiversity and climate change. As soil is the largest terrestrial carbon pool, as well as a significant contributor of greenhouse gases, much progress can be made toward curtailing the climate crisis by sustainable soil management practices. One identified option is to increase soil organic carbon levels, especially with recalcitrant forms of carbon (e.g., biochar application). In general, soil health is primarily determined by the actions of the farming community. Therefore, information management and knowledge sharing are necessary to improve the sustainable behavior of practitioners and end-users. Scientists and policy makers are important actors in this social learning process, not only to disseminate evidence-based scientific knowledge, but also in generating new knowledge in close collaboration with farmers. While governmental funding for soil data collection has been generally decreasing, newly available 5G telecommunications, big data and machine learning based data collection and analytical tools are maturing. Interdisciplinary studies that incorporate such advances may lead to the formation of innovative sustainable soil use and management strategies that are aimed toward optimizing soil health and achieving the SDGs.

Graphical abstract

• • Soil degradation impedes achieving the United Nations' Sustainable Development Goals.
• • Soil plays a fundamental role for biodiversity conservation.
• • Soil researchers ought to prioritize the multifunctional value of soil health.
• • A framework for interdisciplinary research in soil sustainability is presented.
• • Information management and knowledge sharing may drive sustainable behavior change.

1. Introduction

Soil, commonly viewed as a non-renewable resource due to the extremely slow pace of its regeneration, is under serious threat from modern society ( Amundson et al., 2015 ). Soil degradation occurs due to factors such as water erosion, wind erosion, salinization, and deforestation ( Carlson et al., 2012 ; Celentano et al., 2017 ; Rojas et al., 2016 ). Activities that introduce polluting substances, such as heavy metals, pesticides, polycyclic aromatic hydrocarbons (PAHs), are further causing wide-spread soil degradation. Globally, it is estimated that ~24 billion metric tons of soil are lost through factors such as erosion each year ( UNCCD, 2017 ) and that ~30% of the world's soils are now in a degraded state ( FAO, 2011 ). In China, ~19% of agricultural soil and ~ 16% of all soils exceed national soil quality standards ( MEP, 2014 ). Soil degradation threatens the realization of the United Nations Sustainable Development Goals (SDGs) ( Bouma, 2019 ). To help address soil degradation, the United Nations Food and Agriculture Organization declared 2015–2024 as the International Decade of Soils, aiming to raise public awareness of soil protection. Since then, there has been a burgeoning trend of scientific literature and public debate on soil.

Soil is primarily viewed as a critical component of agricultural production in traditional wisdom. In more recent years, the scientific community has increasingly recognized that soil is also an essential component for environmental protection ( Obrist et al., 2017 ), climate change mitigation ( Le Quere et al., 2018 ), ecosystem services ( Bahram et al., 2018 ), as well as land use and planning ( Gossner et al., 2016 ). There is also a growing recognition that soil health relates not only to the classical biogeophysical processes that are traditionally studied by soil scientists, but also information management, knowledge sharing, and human behavior ( Bampa et al., 2019 ; Bouma et al., 2019 ). Interdisciplinary studies (see Section 2.3 ) are required to understand better the coupling of complex human-nature systems linked to soil management ( Bouma and Montanarella, 2016 ). However, current knowledge on soil processes is scattered across various disciplines, lacking comprehensive views on the sustainable management of soil resources ( Vogel et al., 2018 ).

In 2015, the United Nations General Assembly established 17 goals to be achieved by 2030, which are named the Sustainable Development Goals (SDGs). These include, among others, no poverty, zero hunger, good health and wellbeing, clean water and sanitation and climate action ( UN, 2015 ). The SDGs have become a central theme of global development and international collaboration. Considerable progress has been made in recent years toward reaching the SDGs. For example, the proportion of the global population with access to safe drinking water and the percentage of children receiving vaccinations have both risen considerably. However, many challenges still exist, such as: 821 million people remain undernourished, representing a 5% increase between 2015 and 2017; investment in agriculture from governmental sources and foreign aid has dropped; and, atmospheric concentrations of CO 2 and other greenhouse gases (GHGs) continue to rise ( UN, 2019 ), exacerbating the current climate crisis. Governments from local to national levels need to develop integrated programs addressing these sustainability challenges ( Bryan et al., 2018 ).

In the ongoing actions toward reaching the United Nations SDGs, the soil science community has somewhat underplayed the potential role it could play, partly due to the scattered nature of soil knowledge mentioned above. If researchers from wider disciplines were to collaborate more with soil scientists, it may help progress approaches to achieving the SDGs in a manner more effective than acting alone. Therefore, the profile of the soil science discipline may need to be raised, especially the interdisciplinary components that support food security, climate change mitigation, biodiversity, and public health, in order to better design comprehensive strategies toward realizing the SDGs.

In the present paper, we do not reiterate the importance of the interaction between soil science and agronomy covering crop productivity, which has been discussed in other existing publications ( Sanchez, 2002 ; Tisdale et al., 1985 ). Instead, we focus on the interdisciplinary nature of soil and sustainable soil use and management and linkages with soil science with social science, climate science, ecological science, and environmental science.

2. The interdisciplinary nature of sustainable soil use and management

2.1. sustainable development goals (sdgs).

Soil plays a pivotal role in the United Nations SDGs, most notably SDGs 2, 3, 6, 12, 13, and 15 ( Bouma and Montanarella, 2016 ; Keesstra et al., 2016 ). Most people in poverty live in rural areas where crop production is a vital source of income. In these areas, soil health is a decisive factor for productivity and income levels. Among other roles, soil provides the basis for food production and ecosystem services ( Bender et al., 2016 ; Oliver and Gregory, 2015 ). Moreover, as soil biodiversity is related to lower crop diseases and pests, the ecological services offered by healthy soil systems are important in reducing poverty and ending hunger. Soil also affects water quality, GHG emissions, and other important environmental considerations in regard to the SDGs ( Bharati et al., 2002 ; Franzluebbers, 2005 ). An overview of the identified relationships between soil and the relevant SDGs are illustrated in Fig. 1 .

The relevance of soil to the United Nations' Sustainable Development Goals (SDGs).

It is imperative to disseminate soil science knowledge to policy makers and practitioners who design and implement SDG programs (see Section 3 ). Effective action needs to be taken by the soil science community to help develop suitable indicators that are not only scientifically sound, but also practical for small hold farmers and other stakeholders. Scientific research needs to be specifically directed toward realizing the SDGs, rather than to just understand soil science. The influence of human behavior must be factored into this complex human-nature system. It is also necessary to include the impacts of socio-economic activity on soil health when carrying out sustainability assessments, thus allowing more informed decision making ( Vogel et al., 2018 ).

2.2. The soil health concept

Soils have a wide range of physical, chemical, and biological properties that are attributable to the parent material (e.g., geologic origin and depositional processes), environmental factors (e.g., climate conditions, topography) as well as anthropogenic influences (e.g. farming practice, surface disturbance, pollutant emissions). Because soil plays such a critical role in multiple natural and anthropogenic systems, such soil properties will affect ecosystem services, environmental quality, agricultural sustainability, climate change, and human health. This multi-functional aspect makes traditional soil quality evaluation systems, which have tended to focus on soil fertility and agricultural production ( Doran and Parkin, 1994 ), no longer fully appropriate. Most recently, the “soil health” concept has been the subject of increasing research attention (see Fig. 2 ). This holistic approach accounts for non-linear mechanistic relationships between various physical, chemical, and biological properties. Moreover, the soil health holistic concept is advantageous over traditional soil quality assessments because it considers ecosystem services as well as agricultural production, i.e., both nature and human driven objectives ( Kibblewhite et al., 2008 ).

Number of research articles listed in the Web of Science database ( www.webofknowledge.com ) when soil AND sustainability and “soil health” were searched as topics (searched on 3rd March 2020).

Doran and Zeiss (2000) defined soil health as “the capacity of soil to function as a vital living system, within ecosystem and land-use boundaries, to sustain plant and animal productivity, maintain or enhance water and air quality, and promote plant and animal health” Their definition has been well received by the scientific community, as evidenced by the article being cited ~1500 times according to Google Scholar. The authors argued that soil health is a holistic concept which portrays soil as a living system (i.e., the capacity of soil to function as a living system), while soil quality describes a soil's capacity for a specific use (i.e., fitness for different uses). The outcomes of soil use and management decisions are reflected in soil health ( Doran and Safley, 1997 ).

Assessing soil health involves the selection of indicators, quantification or qualitative scoring, and providing a final index with appropriate weighting and integration ( Rinot et al., 2019 ). Biophysical indicators are particularly relevant for assessing soil health. This is because healthy soil is manifested through a variety of soil functions that are reliant upon biological processes, e.g. carbon transformation, nutrient cycling, maintaining soil structure, and regulating pests and disease ( Kibblewhite et al., 2008 ). Scientists have explored the use of soil microorganisms ( Nielsen et al., 2002 ; Van Bruggen and Semenov, 2000 ), enzyme activities ( Ananbeh et al., 2019 ; Janvier et al., 2007 ), earthworms and nematodes ( Neher, 2001 ), as well as other biological indicators to assess soil health. Similarly, soil structure, compaction and moisture retention have been used as physical indicators of soil health.

2.3. Interdisciplinary research

The sustainability of soil systems is affected by their bio-physico-chemical properties, and the soil use and management decisions made by farmers ( Doran and Zeiss, 2000 ). These two aspects can be broadly categorized into natural and anthropogenic processes. Complex dynamics are involved in the coupled human-nature systems, rendering many challenges for the study of soil systems from any single disciplinary lens. We must develop an interdisciplinary approach to address these challenges ( Totsche et al., 2010 ). It should be noted that interdisciplinary approaches differ from multidisciplinary approaches, in that they integrate insights on a common problem (e.g. climate change) from different disciplines (e.g. soil science and climate science) to construct a comprehensive understanding of the issue. In comparison, multidisciplinary approaches involve gaining separate insights on a common problem from the perspectives of different disciplines ( Repko and Szostak, 2020 ).

As many of the problems surrounding soil sustainability are complex and broad, they cannot be sufficiently addressed by one single discipline, thus interdisciplinary studies are needed ( Klein and Newell, 1997 ). Based on a published framework that interconnected disciplinary lines for another topic ( Hammond and Dubé, 2012 ), here we propose a general framework for developing an interdisciplinary perspective on sustainable soil use and management ( Fig. 3 ). We propose that five broad issues have a root in soil science and are linked to at least one other discipline. The issues themselves are also interconnected. Take management and behavior as an example, which is directly linked to soil science and social science. At the same time, soil fertility and soil pollution are also involved, which are directly linked to agronomy and environmental science, respectively. Another example is soil carbon (or soil organic matter) which is directly linked to both soil science and climate science while also affecting soil biodiversity linked to ecology, and soil fertility linked to agronomy. In a sense, the network shown on Fig. 3 forms a complex six-disciplinary system, which can be used for studying soil sustainability.

A framework for interdisciplinary research in soil sustainability linking soil science with social science, environmental science, ecology, climate science, and agronomy.

3. Soil and social science

3.1. knowledge transfer.

A myriad of scientific knowledge exists regarding best practice for soil management. However, there has been a general lack of adoption by farmers ( Bouma, 2019 ). This can be attributed to obstacles that hinder the distribution of relevant scientific information. Scientific evidence from in-depth studies is often scattered within various disciplines that use technical jargon that is little understood by the social scientists or journalists who are engaged in information transmittal and knowledge sharing. Modern electronic information sharing techniques, including social media tools (e.g., Twitter and Facebook), make mass information distribution easier ( Mills et al., 2019 ), but they can also make it difficult for lay people to distinguish between evidence-based reliable information and inaccurate or even misleading information. A parallel example occurred during the novel coronavirus disease (COVID-19) outbreak, during which large amounts of misinformation were transmitted across social media. Scientists felt the need to publish a joint statement to denounce such rumors ( Calisher et al., 2020 ).

Information management and knowledge sharing may help to fill the gap between knowledge generation and its useful application. This is particularly important for the application of soil science. A variety of soil information management and knowledge sharing mechanisms exist, including training workshops (online or offline), websites, social media, advisory services. In Australia, the New South Wales local government uses webinars to disseminate soil science information to a geographically disperse community of practice (CoP) ( Jenkins et al., 2019 ). Grain advisors, however, were reported to be guiding farmers to historically established “rules of thumb” for calculating nitrogen fertilizer needs, rather than the latest evidence-based science on soil water and nitrogen management ( Schwenke et al., 2019 ). Another Australian local government decided to share soil information and knowledge using a website coupled with training workshops. The type of information shared may include soil properties and landscape characteristics obtained from field assessment studies. Such initiatives show that centralized knowledge sharing can bring significant tangible benefits ( Imhof et al., 2019 ). However, a 10-year follow-up survey showed that while training workshops could be effective in the short term, behavioral change was not sustained in the long term. It was suggested that continuing professional development to upskill farm advisors and the CoP may render a more persistent uptake of knowledge at the farm level ( Andersson and Orgill, 2019 ).

In Europe, both private and public sector advisors, operating on national, provincial or local levels offer science communication to farmers ( Ingram and Mills, 2019 ). In Switzerland, sustainable soil management knowledge was successfully shared among farmers via social learning in a video format ( Fry and Thieme, 2019 ). A study in the English East Midlands suggested that soil advisors ought to incorporate hands-on practical knowledge ( Stoate et al., 2019 ). This concurs with another study in Australia, which showed that establishing a network of senior ex-governmental soil scientists and farmers enabled effective soil knowledge transfer ( Packer et al., 2019 ).

As precision agriculture incentivizes the use of sensing technologies to collect soil data, it becomes increasingly important to form public-private partnerships to collect, store, and use the huge amounts of geographically referenced soil data generated ( Robinson et al., 2019 ). The emerging fifth generation of wireless technology for digital cellular networks (5G), big data, and machine learning offer data collection and analysis techniques that may enable a new generation of soil information sharing tools. Within the 5G system, an internet of things (IoT) can be established with low latency, enabling real time soil measurement and response. For instance, unmanned aerial vehicle (UAV) based remote sensing can be coupled with soil amendment delivery in precision agricultural practice ( Kota and Giambene, 2019 ; Morais et al., 2019 ). Big data applications with machine learning also provide predictive power, facilitating smart farming to save energy, water, and cost, while increasing crop yields ( Wolfert et al., 2017 ).

3.2. Farmer behavior

The sustainability of soil use and management is ultimately reliant on the real-world behavior by practitioners, most particularly farmers. Therefore, there is a growing interest to integrate social components and farmer behavior with the ecological component of soil management ( Amin et al., 2019 ). In modern society, with the fast-growing use of various types of information technology, farmer behavior can be influenced by different network-based approaches. For instance, a study in Europe found that farmers formed a learning network by sharing information and soil knowledge on the microblogging and social networking service, Twitter. This platform has a limited length for each message (280 characters for non-Asian languages), making it easy for time-constrained farmers to follow ( Mills et al., 2019 ). In the US, an integrated network-based approach enabled a quarter of respondents to adopt cover crops for weed control, and respondents also increased their follow-up usage from information shared on Twitter (22%), YouTube (23%), and web sites (21%) ( Wick et al., 2019 ).

Farmer behavior and farming practice is also directly affected by professional advisors. In Australia, farmers apply the recommendations of professional crop advisors to select suitable fertilizer dosages. However, attitudes concerning financial risk, soil heterogeneity, and local climate conditions can affect their perception and adoption of such advice ( Schwenke et al., 2019 ). In Europe, a knowledge gap regarding sustainable soil management was identified as a major issue among both farmers and soil advisors. As the current trend of privatization and decentralization of advisory services continues, there is an increasing need to educate those who provide advisory services, thus enabling effective empowerment of farmers ( Ingram and Mills, 2019 ). Governments ought also to provide workshops that encourage farmers to adopt greater soil testing, so that they can then make informed soil management decisions ( Lobry de Bruyn, 2019 ).

Lack of education and awareness creates an obstacle for sustainable soil use and management, especially in developing countries. For example, it was found that farmer perception strongly correlates to adoption rates for conservation agriculture (r = 0.81; p < 0.05) ( Mugandani and Mafongoya, 2019 ). It has been reported that concerns over soil type, weed control, and weather conditions were the main inhibiting factors when English farmers consider reduced tillage practice. The authors suggested that enhanced adoption of sustainable soil management practice will require improved communication between the soil research community and farmers ( Alskaf et al., 2020 ).

3.3. Stakeholders

The creation, dissemination and usage of soil sustainability knowledge involves a wide range of stakeholders, such as scientists, farmers, land managers, advisory services, commercial product suppliers, regulators, funding agencies, educators, students, as well as the general public ( Knox et al., 2019 ; Tulau et al., 2019 ). Different stakeholders will have different concerns. Farmers and crop advisors are primarily concerned about local soil knowledge, while regulators and scientists are more concerned about policy, scientific solutions and the wider environment ( Bampa et al., 2019 ). There is also a dynamic interaction and potential gap between awareness and perception, i.e., what can be done and what is worth doing ( Krzywoszynska, 2019 ). Based on an analysis in England, Krzywoszynska (2019) argued that interactions between soil researchers and end users are multifaceted and that these actors must work together on both knowledge generation and knowledge sharing to enhance sustainable behavior.

Scientists and governments are pivotal stakeholders in promoting sustainable soil use and management practices. Their action can enhance the robustness of scientific knowledge creation and broaden its applicability by incorporating evidence into policy instruments. In Scotland, soil risk maps are created by scientists, policy makers and industrial representatives working in close collaboration ( Baggaley et al., 2020 ). Similarly, in Australia, soil constraints maps have been produced for site-specific management ( van Gool, 2016 ). Such tools can help mitigate constraints to achieving climate-driven genetic yield potential of agricultural crops. Models that incorporate learnings from stakeholder engagement can also render strong predictive power ( Inam et al., 2017 ). Traditionally, the main channel of soil knowledge generation has been government funded. However, there has been a general decreasing trend in the provision of government funds for soil data collection in many developed countries, while privately funded collection of soil information has increased dramatically ( Robinson et al., 2019 ). Under this situation, it is even more important to bring in additional stakeholders to create and share soil knowledge. The Soil Knowledge Network (SKN) in Australia demonstrated that ex-governmental soil scientists can exert long-lasting positive impacts by coaching new generations of early career soil scientists ( McInnes-Clarke et al., 2019 ).

4. Soil and climate science

4.1. soil organic carbon.

Soil organic carbon (SOC) has been recognized as a critical indicator of soil health, because it reflects the level of soil functionality associated with soil structure, hydraulic properties, and microbial activity, thereby integrating physical, chemical and biological health of soil ( Vogel et al., 2018 ). Recently, increasing attention has been placed on SOC beyond the traditional sphere of soil science. This is because it is a key component of Earth's carbon cycle, thus having huge implications for the current climate crisis ( Kell, 2012 ) and SDG13: Climate action. Soil is the largest terrestrial carbon pool, holding an estimated 1500–2400 GtC and permafrost (i.e. frozen soil) storing 1700 GtC ( Le Quere et al., 2018 ). A global initiative known as ‘4 per 1000’, which aims to increase soil organic carbon by 0.4% per year, would result in an additional carbon storage of 1.2 GtC per year if successful ( Paustian et al., 2016 ; Rumpel et al., 2018 ). In Australia, surface soils provide a significant reservoir of carbon, holding ~19 billion metric tons. However, most of these soils (~75%) contain <1% SOC, suggesting huge additional capacity for carbon sequestration. An annual 0.8% increase in carbon storage across all Australian surface soils would fully offset the nation's GHG emissions ( Baldock et al., 2010 )

Soil properties and vegetation are affected by the climatic condition ( Bond-Lamberty et al., 2018 ). For example, global warming may accelerate soil erosion due to its impact on microorganisms and plant and animal species ( Garcia-Pichel et al., 2013 ). Moreover, different soil types and land use systems are unevenly sensitive to temperature changes. Soil carbon that is normally recalcitrant in semi-arid regions is vulnerable to rising temperature ( Maia et al., 2019 ). Therefore, soil management practice in these areas may have a tremendous effect on carbon cycling.

Organic fertilizer applications can improve soil functionality and significantly increase SOC levels. Thus, applying organic amendments, including biosolids and composts, to agricultural land can increase carbon storage and contribute significantly to offsetting GHG emissions. Studies have shown that manure can potentially increase crop yields and soil organic contents in comparison with mineral fertilizers ( Jing et al., 2019 ). A 37-year field study showed that organic fertilization increased soil carbon input by 25% to 80%, although levels of carbon retention ranged from only 1.6% for green manure to 13.7% for fresh cattle manure ( Maltas et al., 2018 ). Similarly, Bolan et al. (2013) demonstrated that biosolid applications likely result in higher levels of carbon sequestration compared to other management strategies including fertilizer application and conservation tillage. This was attributed to an increased microbial biomass, and Fe and Al oxide-induced immobilization of carbon ( Bolan et al., 2013 ). In comparison with open-air systems, the use of organic fertilizers for indoor greenhouse soils may have a greater positive influence on soil functionality due to its effect on porosity and pore connectivity ( Xu et al., 2019 ). It should be noted that organic fertilizers may not increase crops yields to the levels achievable with inorganic fertilizers. This issue can be overcome by supplementing organic fertilizers with inorganic ones ( Maltas et al., 2018 ).

A variety of conservation farming practices can increase SOC levels, while also increasing crop productivity and decreasing water demand ( Kumar et al., 2019 ; Mehra et al., 2018 ). Crop residue return to surface soils can have a positive effect on soil carbon sequestration ( Chowdhury et al., 2015 ; Li et al., 2019b ). For example, chopping and returning wheat straw and corn stover can increase SOC levels by 14.5% in a double-cropping system ( Zhao et al., 2019 ). Reduced tillage and non-tillage practices can also increase soil SOC levels ( Chatskikh et al., 2008 ; Lafond et al., 2011 ). For example, a 22-year study showed that with no tillage, mulch treatment had a significantly positive effect on carbon retention ( Kahlon et al., 2013 ). Integrated methods have the potential to achieve even more significant increases in SOC levels. For example, SOC data collected over 35 years in a semi-arid region of China showed that carbon levels were enhanced (by 453% to 757%) using a combination of best practice cultivation, mulching, and planting methods ( Guoju et al., 2020 ). Different land uses also affect SOC, not only in terms of concentration, but also the fractions of SOC that are vulnerable to mineralization ( Ramesh et al., 2019 ). For example, labile and humified SOC fractions have been reported to be more prone to mineralization in arable lands than in grasslands ( Ukalska-Jaruga et al., 2019 ).

Accurate quantification of SOC remains a challenge because of high spatial heterogeneity in soils. For instance, features such as hedgerows and fences can influence SOC due to their impact on soil moisture and bulk density ( Ford et al., 2019 ). Soil compaction by agricultural machinery reduces macropores and creates water ponding ( Mossadeghi-Björklund et al., 2019 ), which can affect SOC. There are also discrepancies between SOC estimates using regional versus local parameters, particularly for in woodland soils containing large amounts of decaying organic matter (e.g., Histosols) and low-input high-diversity ecosystems ( Ottoy et al., 2019 ).

4.2. Biochar as a mitigation

Biochar is a carbon rich product that is produced by the burning of biomass with a limited supply of oxygen (i.e., pyrolysis) ( Lehmann and Joseph, 2009 ; Wang et al., 2020c ). It typically possess a stable fixed carbon structure with high porosity, a high specific surface area and a high alkalinity. These characteristics enable biochar to enhance soil moisture content, sorb polluting substances and increase soil pH ( Andrés et al., 2019 ). Moreover, biochar is considered carbon negative because the carbon within its structure, which is captured from the atmosphere during biomass formation, is more recalcitrant in the natural environment than carbon in biomass that has not been pyrolized. Because of its carbon negativity and beneficial properties for soil management, biochar has been proposed as a possible technology to help mitigate climate change ( Woolf et al., 2010 ). Numerous studies have explored the usage of biochar in croplands ( Laird et al., 2010b ), while recent studies have also examined its application in other systems, such as alpine grassland ( Rafiq et al., 2019 ).

At the current carbon price, applying biochar to soil is not commercially viable unless there is an additional benefit to farmers. Therefore, researchers have conducted extensive research on the benefits biochar for agricultural and environmental purposes. One of the most researched areas is the use of biochar to increase crop yields. A recent meta-analysis found that in comparison with inorganic fertilizer alone, biochar can increase crop yields by 11% to 19% (95% confidence intervals) ( Ye et al., 2020 ). Biochar has also been put forward as a sustainable technique for remediating soils degraded by contaminants, especially heavy metals ( Hou, 2020 ; O'Connor et al., 2018c ; Song et al., 2019 ). The sustainability of biochar is increased if the biomass feedstock is a biological waste that would otherwise be burned or discarded at landfill, thus avoiding air pollution or the consumption of landfill space. However, while a myriad of studies have shown biochar applications have positive effects on soil, it should be noted that such effects may diminish after 3– 5 years ( Dong et al., 2019 ). Biochar effectiveness and longevity may be enhanced by the invention of engineered biochars ( O'Connor et al., 2018b ).

4.3. Soil greenhouse gases

Soils act as significant sources of various greenhouse gases (GHGs), including CO 2 , CH 4 , and N 2 O. Reducing the emission of such GHGs is one of the greatest challenges for sustainable farming ( de Araújo Santos et al., 2019 ) and the achievement of SDG13: Climate action. Soil CO 2 emissions are affected by agricultural practice (e.g. tillage and fertilizer application), as well as the soil properties (e.g. soil texture). For sandy soils, greater macroporosity tends to be associated with higher CO 2 emissions, while microporosity is associated with lower emissions, which likely related to their respective tortuosity levels ( Farhate et al., 2019 ; Tavares et al., 2015 ). The use of lime to treat low pH soils may also relate to CO 2 emissions. Therefore, sustainable management of low pH grasslands may involve the use of low liming dosage rates, which provide almost the same result as higher rates ( Bolan et al., 2003 ; Kunhikrishnan et al., 2016 ; Lochon et al., 2019 ). A study in Denmark showed that reduced tillage practice can decrease net GHG emissions by 0.56 Mg CO 2 -eq. ha −1 per year; moreover, the use of disc coulters that minimally disturb soil can reduce net GHG emissions by 1.84 Mg CO 2 -eq. ha −1 per year ( Chatskikh et al., 2008 ).

Atmospheric N 2 O accounts for ~6% of radiative forcing caused by anthropogenic activity, which largely stems from soil systems ( Davidson, 2009 ). Therefore, emission of N 2 O from agricultural soil is particularly concerning. Davidson (2009) estimated that 2% of nitrogen in manures and 2.5% of nitrogen in fertilizers used by farmers over the period of 1860–2005 was converted to atmospheric N 2 O. In China, emissions derived from synthetic nitrogen fertilizers account for ~7% of the nation's annual GHG budget. By implementing new technology and best management practices that minimize nitrogen use in soil management, it is feasible to reduce GHG emissions by 102–357 Tg CO 2 -equivalent in China alone ( Zhang et al., 2013 ). Soil amendment with more sustainable alternatives to synthetic nitrogen (e.g., biochar) may help reduce N 2 O emissions from soil ( Senbayram et al., 2019 ).

Methane emissions from soil represent another major factor for climate change. An early study found that the application of rice straw to paddy fields increased CH 4 emissions by a factor of 1.8 to 3.5 ( Yagi and Minami, 1990 ). Recently, methane emissions from permafrost (permanently frozen soil) has drawn attention from the climate science community, owing to its critical role in carbon cycling ( Schuur et al., 2015 ). As climate change occurs, rising temperature in the polar regions causes permafrost to thaw and microbial activity to increase ( Hollesen et al., 2015 ). This leads to increased methane and CO 2 emissions from organic-rich Arctic soils ( Schuur et al., 2013 ). As these gases are associated with increased global warming potential, their emission increases the levels of permafrost thaw, thus forming a positive feedback loop. It is imperative to understand these processes in a quantitative way. As the climate change crisis worsens, it may be necessary to take mitigating measures involving soil management in areas associated with high methane fluxes.

5. Soil biodiversity and ecology

5.1. soil biodiversity.

Sustainable soil management practice can improve or conserve soil biodiversity, which represent a significant proportion of Earth's total biodiversity ( Bahram et al., 2018 ) and is pertinent to the achievement of the United Nations' SDGs (e.g., SDG15: Life on land). Among other factors, soil microbial communities are affected by the availability of nutrients corresponding to the type of soil management practice ( Bolan et al., 1996 ; Lauber et al., 2009 ; Leff et al., 2015 ). For example, the use of soluble fertilizers (e.g., monocalcium phosphate), less soluble organic fertilizer (e.g., sugarcane filter cake) or nearly insoluble rock phosphate ( Arruda et al., 2019 ) have different impacts on soil microbial communities. Soil management practices also affect soil hydraulics, which affects plant and microbial biodiversity and ecosystem resilience ( Alley et al., 2002 ; Anderegg et al., 2018 ). A study in India reported that integrating crop residue return with green manure application and no-tillage in a rice-wheat double cropping system increased SOC levels by 13%, the microbial biomass by 38%, the basal soil respiration rate by 33%, and the microbial quotient by 30% ( Saikia et al., 2020 ). Certain soil amendments are associated with increased soil biodiversity. For example, biochar amendment of a Mediterranean vineyard soil decreased the mineralization of both SOC and microbial biomass, while the functional microbial diversity and biodiversity of soil micro-arthropods were maintained ( Andrés et al., 2019 ). Soil properties and biodiversity are also affected by plant root systems within the rhizosphere ( Dey et al., 2012 ).

Larger species in soil are also an important aspect of soil biodiversity as well as being influential on soil properties ( Bardgett and van der Putten, 2014 ; Wu et al., 2011 ). Earthworms (Oligochaeta) are a particularly important soil species due to their creation of soil macro-pores (>0.3 mm) and channels (burrows) that increase water and gas infiltration rates ( Bartz et al., 2013 ; Bhadauria and Saxena, 2010 ). Thus earthworm activity can render soil environments that are more amenable to microbial activity and diversity ( Eriksen-Hamel et al., 2009 ). Conservation tillage practices that involve crop residue return to surface soils can increase earthworm numbers by hundreds of thousands per hectare ( Barthod et al., 2018 ; Giannitsopoulos et al., 2020 )

5.2. Ecosystem services

Soils provide vital ecosystem services, rendering both economic and societal benefits ( Adhikari and Hartemink, 2016 ; Dominati et al., 2010 ; Pavan and Ometto, 2018 ; Su et al., 2018 ). Monetary valuation methods have been put forward to account for the natural capital of this resource ( Robinson et al., 2014 ). In this way, a national-scale study in the UK suggested that an additional £18 billion GBP of ecosystem services could be achieved under an optimal policy scenario. This value takes into account major ecosystem services, such as agricultural production, carbon sequestration, recreational usage, and wildlife diversity ( Bateman et al., 2013 ). However, some scholars have argued that systematic monetarization is unnecessary. For example, Bayesian Belief Networks (BBNs) and Multi-Criteria Decision Analysis (MCDA) methods can provide decision makers with semi-quantitative information that takes into account the multifunctionality of soil ecosystem services ( Baveye et al., 2016 ).

Living organisms in soil have a direct impact on agricultural productivity and ecosystem services. For instance, the microbial community is essential for the natural decontamination of polluted soils. Therefore, monitoring biological indicators is necessary for managing soil ecosystems effectively. Some of the most important soil biota indicators include microsymbionts, decomposers, elemental transformers, soil ecosystem engineers, soil-borne pests and diseases, and microregulators ( Barrios, 2007 ). Soil invertebrates also play a significant role in soil ecosystem services ( Lavelle et al., 2006 ).

In Europe, a large number of monitoring programs and field studies have been conducted since the 1990s, to gain data for optimizing ecosystem services ( Pulleman et al., 2012 ). The data shows that spatial heterogeneity within soil systems translates into the uneven distribution of ecosystem services ( Aitkenhead and Coull, 2019 ). Governments may intervene to restore or improve ecological services in limited soil systems. In China, for example, the government has made subsidies available to farmers to protect natural woodlands and convert steep agricultural cropland into other land uses, such as grassland or woodland ( Liu et al., 2008 ). If farmland is degraded to an extent that it is abandoned, soil treatments may help bring about natural revegetation and the recovery of ecosystem services ( Li et al., 2019a ). For example, the recovery of severely degraded land can be facilitated by the use of soil amendments such as biochar ( O'Connor et al., 2018c ).

6. Soil and environmental science

6.1. soil pollution.

Contaminants are an issue for many agricultural sites ( Bolan et al., 2014 ; Khan, 2016 ; O'Connor et al., 2019b ; Wilcke, 2000 ), which hinders efforts toward the achievement of the United Nations' SDGs (e.g., SDG3: Good health and well-being). Soil contaminants include heavy metals, such as cadmium (Cd), copper (Cu), lead (Pb), mercury (Hg) and zinc (Zn), and organic pollutants, such as pesticides and polycyclic aromatic hydrocarbons (PAHs). As an emerging contaminant, microplastics in the soil environment have also drawn attention in recent years ( Bradney et al., 2019 ; Jia et al., 2020 ; O'Connor et al., 2020 ; Wang et al., 2020a ). Assessment of their fate and transport is critical for understanding the environmental risk ( Corradini et al., 2019 ; Wang et al., 2019a ).

A global map of soil pollution is urgently needed to understand better the situation globally, but few countries are investing in national-scale investigations ( Hou and Ok, 2019 ). Elevated levels of soil pollutants can result from a wide variety of anthropogenic activities, ranging from metal mining to fossil fuel burning ( Zhang et al., 2020b ). The spatial redistribution of these pollutants involves inter-phase transfer such as dissolution from soil to water, volatilization from soil to air, and deposition from air to soil ( O'Connor et al., 2019a ; Zhang et al., 2019 ). Anthropogenic soil pollution in under-developed regions where industrial activities are less intensive can also occur due to traffic and mining related emissions, etc. For instance, a recent study in a suburban area of Central Asia showed that Pb, Zn, and Cu can accumulate to high levels in soils because of road traffic up to 200 m away ( Ma et al., 2019 ).

The remediation of contaminated soil is an important research field interlinking soil science and environmental science. Traditionally, remediation practitioners focused on either physical cleanup methods, such as soil excavation and disposal at landfill ( Qi et al., 2020 ), or chemical treatment methods, such as in situ chemical oxidation ( O'Connor et al., 2018a ). In recent years, nature-based solutions, such as phytoremediation and green stabilization, have gained attention among the scientific research community ( Wang et al., 2019b ; Wang et al., 2020b ; Zhang et al., 2020a ). For example, microbial strains from unique natural environments are being harvested, cultured, and exploited to render economic and environmentally friendly solutions for soil decontamination ( Atashgahi et al., 2018 ; Bunge et al., 2003 ).

6.2. Soil erosion

Soil erosion, a major land degradation process, is caused by the weathering effects of water and wind ( Lal, 2003 ). For land covered by native vegetation, natural erosion rates will tend to balance with soil production rates. However, typical agricultural tillage practice can disrupt this balance, causing levels of soil erosion to be one to two orders of magnitude higher than that of soil formation ( Montgomery, 2007b ). Soil systems that experience net soil erosion can suffer the loss of fertile surface soils, removal of soil organic carbon, and reduced agricultural productivity, thus rendering a high environmental and economic cost globally ( Montgomery, 2007a ; Pimentel et al., 1995 ). Because heavy metals tend to bind strongly to eroded soil particles, the widespread distribution of soil pollutants is also often associated with soil erosion ( Xiao et al., 2019 ).

Soil erosion not only causes damage to the land where it occurs, but also jeopardizes local aquatic systems due to excessive sediment loading ( Boardman et al., 2019 ). Soil erosion models have been developed to predict impacts of water quality on a catchment-scale ( Fu et al., 2019 ). It can also cause damage to nearby housing due to increased surface runoff and landslides. Because of such impacts, many governments are taking largescale mitigating action, such as revegetation with native species and woodland restoration ( Teng et al., 2019 ).

6.3. Soil leaching

During heavy rainfall, irrigation, or recharge events, large volumes of water may come into contact with various substances as soil pore spaces fill ( O'Connor and Hou, 2019 ). In this process, there are complex interactions between gaseous, liquid, and solid phases for soil nutrients, potentially toxic elements, and organic pollutants. If soil nutrients or contaminants are leached from surface soils, they can transport into the subsurface via the vertical migration of infiltration water. This can lead to large scale groundwater pollution involving substances such as ammonia ( Jia et al., 2019 ). Leached nutrients in surface runoff may also enter nearby surface water bodies, causing eutrophication ( Maguire and Sims, 2002 ). Soil leaching may be particularly prominent in the autumn-winter season due to reduced plant activity ( Welten et al., 2019 ).

Soil leaching potential is exacerbated by common physical farming practices, including the installation of deep drainage ( Nachimuthu et al., 2019 ). The potential for soil leaching is also affected by soil management practices that alter the chemical composition of soil. For instance, liming is a common farming method to increase soil pH and reduce flocculation. However, recent studies have suggested that soil particle surfaces become more negatively charged as soil pH increases. Therefore, liming activity may lead to soil-bound harmful substances, such as perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), leaching from soil and entering groundwater systems ( Oliver et al., 2019 ). In New Zealand, intensified agricultural production on steep landscapes, which is encouraged by the government's policy to significantly increase agricultural exports, has involved the replacement of perennial pastures with winter forage crops. This has increased the use agrochemicals, including glyphosate and diazinon, which not only pose an environmental risk in themselves, but also facilitate the leaching of organic carbon and nitrogen ( Chibuike et al., 2019 ). The reporting of such unintended consequences reinforces the importance of comprehensive assessments for sustainable soil use and management. It should be noted that certain soil amendments, such as biochar, have been shown to reduce soil nutrient leaching potential ( Laird et al., 2010a ).

Soil leaching can increase the spatial heterogeneity of soil nutrients, which makes soil management more difficult. For instance, intensively farmed cropland tends to be subject to high nitrogen input levels. However, plant-animal-soil systems are not efficient in utilizing large amounts of nitrogen, with only 15–35% being embedded in agricultural products. A large percentage of the surplus nitrogen is returned to localized spots via animal urinary excretions, resulting in elevated nitrogen hotspots.

7. Summary, challenges and future directions

The international community's commitment to achieving the United Nations' Sustainable Development Goals (SDGs) hinge on soil health. However, neither the scientific community nor policy makers have paid sufficient attention to soil in their SDG efforts. Soil scientists have not been adequately involved in the discussion on SDG targets and indicators ( Bouma et al., 2019 ). Consequently, while there are four SDG targets that specifically mention soil, and others that indirectly relate to soil, only one explicit soil indicator has been established ( Bouma et al., 2019 ). The lack of involvement by soil scientists may be due to their strong focus on pure soil science, rather than conducting cross-disciplinary and elaborate discussions on big picture soil related issues with other stakeholders. To help provide effective SDG solutions, it is imperative to encourage interdisciplinary soil research among soil scientists and researchers in fields relating to social science, climate science, ecology, and environmental science. When national and local governments form policies according to the United Nations SDGs, soil scientists need to be encouraged to play a more active role, and their advice needs to be sought by decision makers. For instance, by nominating soil scientists to key steering committees.

A big challenge for sustainable soil use and management is the inherent spatial heterogeneity of soil properties, from the micro to the global scale. This makes it difficult to predict non-linear relationships among various soil processes and system behaviors ( Manzoni and Porporato, 2009 ). For example, regional estimates of soil organic carbon stocks have differed by as much as 60% on different scales due to this heterogeneity ( Illiger et al., 2019 ). There is little known about the vertical distribution of organic carbon in the subsurface ( Balesdent et al., 2018 ). As large amounts of carbon are stored in deep soils ( Yu et al., 2019 ), it is essential to understand the status, as well as the mechanisms, of soil carbon cycling across the full extent of the lithosphere.

Spatial heterogeneity also exists in socioeconomic systems. Consider for example the size of typical farm holdings among different countries. In rural China, most farms are smallholdings of <0.5 ha. In Hungary, most farms are also relatively small, with 79% being <2 ha. In contrast, Danish farms tend to quite large, with 55% being larger than 20 ha ( Ingram and Mills, 2019 ). Such differences create challenges for knowledge transfer between countries. For instance, farm size may act as a barrier to the adoption of sustainable farming technology because of financial or technical constraints ( Alskaf et al., 2020 ).

It is important to describe long-term temporal trends in soil system behavior because many prominent issues, such as the climate crisis, require perceptive solutions based on long-term evidence. However, many existing studies, especially studies on emerging issues, are based on short-term findings. For instance, a recent pasture-system study suggested that various species could be planted to control nitrogen leaching associated with cow urine ( Welten et al., 2019 ). This promising finding, however, was based on less than one year of data. Longer-term studies are necessary to verify the effectiveness of such strategies. Greater efforts should be paid on the research and development of accelerated aging techniques ( Shen et al., 2019 )

Progress in sustainable soil use and management relies upon the development of suitable and holistic indicators for soil health that reflect the diverse processes involved, in a concise, quantifiable, reliable and meaningful way. To achieve this goal, soil health needs to be evaluated under site-specific conditions that account for the different processes of different geological, climatic, and societal conditions ( Vogel et al., 2018 ). This would be particularly valuable for aiding farmers with decision making and translating soil science into practical sustainable soil use and management practice. Moreover, to support policy making processes, it is necessary to map soil properties on a regional scale, or even on national and global scales. High resolution mapping and clustering of soil properties would enable targeted recommendations for sustainable soil management ( Donoghue et al., 2019 ). It should also be noted that while many existing soil sustainability studies have focused on the impacts of socioeconomic activities (i.e. soil management) on soil systems (i.e. soil health), studies regarding the impacts of soil systems on socioeconomic systems are less common ( Vogel et al., 2018 ).

Information management and knowledge sharing are critical for building collaborative governance and delivering sustainable solutions ( Bodin, 2017 ). In this new era of information, massive amounts of valuable information (and misinformation) are produced. This poses a challenge to both the knowledge creators, who struggle to make it visible in an ocean of information, and the knowledge users, who struggle to distinguish whether information is valuable or not. Emerging and advanced technologies, such as 5G, big data and machine learning present great opportunities for addressing these challenges. Interdisciplinary studies initiated by, or in collaboration with, communication engineers and computer scientists hold much potential in advancing our capability in sustainable use and management of soil resources.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

This work was supported by the National Key Research and Development Program of China (Grant No. 2018YFC1801300).

Editor: Jay Gan

• Adhikari K., Hartemink A.E. Linking soils to ecosystem services—a global review. Geoderma. 2016; 262 :101–111. [ Google Scholar ]
• Aitkenhead M.J., Coull M.C. Digital mapping of soil ecosystem services in Scotland using neural networks and relationship modelling. Part 2: mapping of soil ecosystem services. Soil Use Manag. 2019; 35 :217–231. [ Google Scholar ]
• Alley W.M., Healy R.W., LaBaugh J.W., Reilly T.E. Hydrology - flow and storage in groundwater systems. Science. 2002; 296 :1985–1990. [ PubMed ] [ Google Scholar ]
• Alskaf K., Sparkes D.L., Mooney S.J., Sjögersten S., Wilson P. The uptake of different tillage practices in England. Soil Use Manag. 2020; 36 :27–44. [ Google Scholar ]
• Amin M.N., Hossain M.S., Lobry de Bruyn L., Wilson B. A systematic review of soil carbon management in Australia and the need for a social-ecological systems framework. Sci. Total Environ. 2019:135182. [ PubMed ] [ Google Scholar ]
• Amundson R., Berhe A.A., Hopmans J.W., Olson C., Sztein A.E., Sparks D.L. Soil and human security in the 21st century. Science. 2015; 348 [ PubMed ] [ Google Scholar ]
• Ananbeh H., Stojanović M., Pompeiano A., Voběrková S., Trasar-Cepeda C. Use of soil enzyme activities to assess the recovery of soil functions in abandoned coppice forest systems. Sci. Total Environ. 2019; 694 [ PubMed ] [ Google Scholar ]
• Anderegg W.R.L., Konings A.G., Trugman A.T., Yu K., Bowling D.R., Gabbitas R. Hydraulic diversity of forests regulates ecosystem resilience during drought. Nature. 2018; 561 :538. [ PubMed ] [ Google Scholar ]
• Andersson K.O., Orgill S.E. Soil extension needs to be a continuum of learning; soil workshop reflections 10 years on. Soil Use Manag. 2019; 35 :117–127. [ Google Scholar ]
• Andrés P., Rosell-Melé A., Colomer-Ventura F., Denef K., Cotrufo M.F., Riba M. Belowground biota responses to maize biochar addition to the soil of a Mediterranean vineyard. Sci. Total Environ. 2019; 660 :1522–1532. [ PubMed ] [ Google Scholar ]
• de Araújo Santos G.A., Moitinho M.R., de Oliveira Silva B., Xavier C.V., Teixeira D.D.B., Corá J.E. Effects of long-term no-tillage systems with different succession cropping strategies on the variation of soil CO2 emission. Sci. Total Environ. 2019; 686 :413–424. [ PubMed ] [ Google Scholar ]
• Arruda B., Rodrigues M., Gumiere T., Richardson A.E., Andreote F.D., Soltangheisi A. The impact of sugarcane filter cake on the availability of P in the rhizosphere and associated microbial community structure. Soil Use Manag. 2019; 35 :334–345. [ Google Scholar ]
• Atashgahi S., Sanchez-Andrea I., Heipieper H.J., van der Meer J.R., Stams A.J.M., Smidt H. Prospects for harnessing biocide resistance for bioremediation and detoxification. Science. 2018; 360 :743–746. [ PubMed ] [ Google Scholar ]
• Baggaley N., Lilly A., Blackstock K., Dobbie K., Carson A., Leith F. Soil risk maps–interpreting soils data for policy makers, agencies and industry. Soil Use Manag. 2020; 36 :19–26. [ Google Scholar ]
• Bahram M., Hildebrand F., Forslund S.K., Anderson J.L., Soudzilovskaia N.A., Bodegom P.M. Structure and function of the global topsoil microbiome. Nature. 2018; 560 :233. [ PubMed ] [ Google Scholar ]
• Baldock J., Sanderman J., Farquharson R. Proceedings of the 19th World Congress of Soil Science. 2010. Capturing carbon in Australian soils: Potential and realities; pp. 1–6. [ Google Scholar ]
• Balesdent J., Basile-Doelsch I., Chadoeuf J., Cornu S., Derrien D., Fekiacova Z. Atmosphere-soil carbon transfer as a function of soil depth. Nature. 2018; 559 :599. [ PubMed ] [ Google Scholar ]
• Bampa F., O’Sullivan L., Madena K., Sandén T., Spiegel H., Henriksen C.B. Harvesting European knowledge on soil functions and land management using multi-criteria decision analysis. Soil Use Manag. 2019; 35 :6–20. [ Google Scholar ]
• Bardgett R.D., van der Putten W.H. Belowground biodiversity and ecosystem functioning. Nature. 2014; 515 :505–511. [ PubMed ] [ Google Scholar ]
• Barrios E. Soil biota, ecosystem services and land productivity. Ecol. Econ. 2007; 64 :269–285. [ Google Scholar ]
• Barthod J., Rumpel C., Calabi-Floody M., Mora M.-L., Bolan N., Dignac M.-F. Adding worms during composting of organic waste with red mud and fly ash reduces CO2 emissions and increases plant available nutrient contents. J. Environ. Manag. 2018; 222 :207–215. [ PubMed ] [ Google Scholar ]
• Bartz M.L.C., Pasini A., Brown G.G. Earthworms as soil quality indicators in Brazilian no-tillage systems. Appl. Soil Ecol. 2013; 69 :39–48. [ Google Scholar ]
• Bateman I.J., Harwood A.R., Mace G.M., Watson R.T., Abson D.J., Andrews B. Bringing ecosystem services into economic decision-making: land use in the United Kingdom. Science. 2013; 341 :45–50. [ PubMed ] [ Google Scholar ]
• Baveye P.C., Baveye J., Gowdy J. Soil “ecosystem” services and natural capital: critical appraisal of research on uncertain ground. Frontiers in Environmental Science. 2016; 4 :41. [ Google Scholar ]
• Bender S.F., Wagg C., van der Heijden M.G. An underground revolution: biodiversity and soil ecological engineering for agricultural sustainability. Trends Ecol. Evol. 2016; 31 :440–452. [ PubMed ] [ Google Scholar ]
• Bhadauria T., Saxena K.G. Role of earthworms in soil fertility maintenance through the production of biogenic structures. Applied and environmental soil science. 2010; 2010 [ Google Scholar ]
• Bharati L., Lee K.-H., Isenhart T., Schultz R. Soil-water infiltration under crops, pasture, and established riparian buffer in Midwestern USA. Agrofor. Syst. 2002; 56 :249–257. [ Google Scholar ]
• Boardman J., Vandaele K., Evans R., Foster I.D. Off-site impacts of soil erosion and runoff: why connectivity is more important than erosion rates. Soil Use Manag. 2019; 35 :245–256. [ Google Scholar ]
• Bodin O. Collaborative environmental governance: achieving collective action in social-ecological systems. Science. 2017; 357 :659–+. [ PubMed ] [ Google Scholar ]
• Bolan N., Currie L., Baskaran S. Assessment of the influence of phosphate fertilizers on the microbial activity of pasture soils. Biol. Fertil. Soils. 1996; 21 :284–292. [ Google Scholar ]
• Bolan N.S., Adriano D.C., Curtin D. Soil acidification and liming interactions with nutrient and heavy metal transformation and bioavailability. Adv. Agron. 2003; 78 :5–272. [ Google Scholar ]
• Bolan N.S., Kunhikrishnan A., Naidu R. Carbon storage in a heavy clay soil landfill site after biosolid application. Sci. Total Environ. 2013; 465 :216–225. [ PubMed ] [ Google Scholar ]
• Bolan N., Kunhikrishnan A., Thangarajan R., Kumpiene J., Park J., Makino T. Remediation of heavy metal (loid) s contaminated soils–to mobilize or to immobilize? J. Hazard. Mater. 2014; 266 :141–166. [ PubMed ] [ Google Scholar ]
• Bond-Lamberty B., Bailey V.L., Chen M., Gough C.M., Vargas R. Globally rising soil heterotrophic respiration over recent decades. Nature. 2018; 560 :80. [ PubMed ] [ Google Scholar ]
• Bouma J. How to communicate soil expertise more effectively in the information age when aiming at the UN Sustainable Development Goals. Soil Use Manag. 2019; 35 :32–38. [ Google Scholar ]
• Bouma J., Montanarella L. Facing policy challenges with inter-and transdisciplinary soil research focused on the UN Sustainable Development Goals. Soil. 2016; 2 :135. [ Google Scholar ]
• Bouma J., Montanarella L., Evanylo G. The challenge for the soil science community to contribute to the implementation of the UN Sustainable Development Goals. Soil Use Manag. 2019; 35 :538–546. [ Google Scholar ]
• Bradney L., Wijesekara H., Palansooriya K.N., Obadamudalige N., Bolan N.S., Ok Y.S. Particulate plastics as a vector for toxic trace-element uptake by aquatic and terrestrial organisms and human health risk. Environ. Int. 2019; 131 [ PubMed ] [ Google Scholar ]
• Bryan B.A., Gao L., Ye Y., Sun X., Connor J.D., Crossman N.D. China’s response to a national land-system sustainability emergency. Nature. 2018; 559 :193–204. [ PubMed ] [ Google Scholar ]
• Bunge M., Adrian L., Kraus A., Opel M., Lorenz W.G., Andreesen J.R. Reductive dehalogenation of chlorinated dioxins by an anaerobic bacterium. Nature. 2003; 421 :357–360. [ PubMed ] [ Google Scholar ]
• Calisher C., Carroll D., Colwell R., Corley R.B., Daszak P., Drosten C. Statement in support of the scientists, public health professionals, and medical professionals of China combatting COVID-19. Lancet. 2020; 395 (10226):PE42–E43. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Carlson K.M., Curran L.M., Ratnasari D., Pittman A.M., Soares-Filho B.S., Asner G.P. Committed carbon emissions, deforestation, and community land conversion from oil palm plantation expansion in West Kalimantan, Indonesia. Proc. Natl. Acad. Sci. U. S. A. 2012; 109 :7559–7564. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Celentano D., Rousseau G.X., Engel V.L., Zelarayán M., Oliveira E.C., Araujo A.C.M. Degradation of riparian forest affects soil properties and ecosystem services provision in eastern Amazon of Brazil. Land Degrad. Dev. 2017; 28 :482–493. [ Google Scholar ]
• Chatskikh D., Olesen J.E., Hansen E.M., Elsgaard L., Petersen B.M. Effects of reduced tillage on net greenhouse gas fluxes from loamy sand soil under winter crops in Denmark. Agric. Ecosyst. Environ. 2008; 128 :117–126. [ Google Scholar ]
• Chibuike G., Burkitt L., Camps-Arbestain M., Bishop P., Bretherton M., Singh R. Effect of forage crop establishment on dissolved organic carbon dynamics and leaching in a hill country soil. Soil Use Manag. 2019; 35 :453–465. [ Google Scholar ]
• Chowdhury S., Farrell M., Butler G., Bolan N. Assessing the effect of crop residue removal on soil organic carbon storage and microbial activity in a no-till cropping system. Soil Use Manag. 2015; 31 :450–460. [ Google Scholar ]
• Corradini F., Meza P., Eguiluz R., Casado F., Huerta-Lwanga E., Geissen V. Evidence of microplastic accumulation in agricultural soils from sewage sludge disposal. Sci. Total Environ. 2019; 671 :411–420. [ PubMed ] [ Google Scholar ]
• Davidson E.A. The contribution of manure and fertilizer nitrogen to atmospheric nitrous oxide since 1860. Nat. Geosci. 2009; 2 :659. [ Google Scholar ]
• Dey R., Pal K.K., Tilak K.V.B.R. Influence of soil and plant types on diversity of rhizobacteria. Proceedings of the National Academy of Sciences India Section B-Biological Sciences. 2012; 82 :341–352. [ Google Scholar ]
• Dominati E., Patterson M., Mackay A. A framework for classifying and quantifying the natural capital and ecosystem services of soils. Ecol. Econ. 2010; 69 :1858–1868. [ Google Scholar ]
• Dong X., Singh B.P., Li G., Lin Q., Zhao X. Biochar has little effect on soil dissolved organic carbon pool 5 years after biochar application under field condition. Soil Use Manag. 2019; 35 :466–477. [ Google Scholar ]
• Donoghue S., Furley P.A., Stuart N., Haggis R., Trevaskis A., Lopez G. The nature and spatial variability of lowland savanna soils: improving the resolution of soil properties to support land management policy. Soil Use Manag. 2019; 35 :547–560. [ Google Scholar ]
• Doran J.W., Parkin T.B. Defining and assessing soil quality. Defining soil quality for a sustainable environment. 1994; 35 :1–21. [ Google Scholar ]
• Doran J., Safley M. CAB International; New York: 1997. Defining and Assessing Soil Health and Sustainable Productivity. Biological Indicators of Soil Health. [ Google Scholar ]
• Doran J.W., Zeiss M.R. Soil health and sustainability: managing the biotic component of soil quality. Appl. Soil Ecol. 2000; 15 :3–11. [ Google Scholar ]
• Eriksen-Hamel N.S., Speratti A.B., Whalen J.K., Légère A., Madramootoo C.A. Earthworm populations and growth rates related to long-term crop residue and tillage management. Soil Tillage Res. 2009; 104 :311–316. [ Google Scholar ]
• FAO . Earthscan; 2011. The State of the World’s Land and Water Resources for Food and Agriculture: Managing Systems at Risk. [ Google Scholar ]
• Farhate C.V., de Souza Z.M., La Scala N., Jr., de Sousa A.C.M., Santos A.P.G., Carvalho J.L.N. Soil tillage and cover crop on soil CO2 emissions from sugarcane fields. Soil Use Manag. 2019; 35 :273–282. [ Google Scholar ]
• Ford H., Healey J.R., Webb B., Pagella T.F., Smith A.R. How do hedgerows influence soil organic carbon stock in livestock-grazed pasture? Soil Use Manag. 2019; 35 :576–584. [ Google Scholar ]
• Franzluebbers A.J. Soil organic carbon sequestration and agricultural greenhouse gas emissions in the southeastern USA. Soil Tillage Res. 2005; 83 :120–147. [ Google Scholar ]
• Fry P., Thieme S. A social learning video method: identifying and sharing successful transformation knowledge for sustainable soil management in Switzerland. Soil Use Manag. 2019; 35 :185–194. [ Google Scholar ]
• Fu B., Merritt W.S., Croke B.F., Weber T.R., Jakeman A.J. A review of catchment-scale water quality and erosion models and a synthesis of future prospects. Environ. Model Softw. 2019; 114 :75–97. [ Google Scholar ]
• Garcia-Pichel F., Loza V., Marusenko Y., Mateo P., Potrafka R.M. Temperature drives the continental-scale distribution of key microbes in topsoil communities. Science. 2013; 340 :1574–1577. [ PubMed ] [ Google Scholar ]
• Giannitsopoulos M.L., Burgess P.J., Rickson R.J. Effects of conservation tillage drills on soil quality indicators in a wheat–oilseed rape rotation: organic carbon, earthworms and water-stable aggregates. Soil Use Manag. 2020; 36 :139–152. [ Google Scholar ]
• van Gool D. 2016. Identifying Soil Constraints That Limit Wheat Yield in the South-west of Western Australia. [ Google Scholar ]
• Gossner M.M., Lewinsohn T.M., Kahl T., Grassein F., Boch S., Prati D. Land-use intensification causes multitrophic homogenization of grassland communities. Nature. 2016; 540 :266–+. [ PubMed ] [ Google Scholar ]
• Guoju X., Yanbin H., Qiang Z., Jing W., Ming L. Impact of cultivation on soil organic carbon and carbon sequestration potential in semiarid regions of China. Soil Use Manag. 2020; 36 :83–92. [ Google Scholar ]
• Hammond R.A., Dubé L. A systems science perspective and transdisciplinary models for food and nutrition security. Proc. Natl. Acad. Sci. 2012; 109 :12356–12363. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Hollesen J., Matthiesen H., Møller A.B., Elberling B. Permafrost thawing in organic Arctic soils accelerated by ground heat production. Nat. Clim. Chang. 2015; 5 :574–578. [ Google Scholar ]
• Hou D. Elsevier Inc; 2020. Sustainable Remediation of Contaminated Soil and Groundwater: Materials, Processes, and Assessment. [ Google Scholar ]
• Hou D., Ok Y.S. Speed up mapping of soil pollution. Nature. 2019; 566 :455. [ PubMed ] [ Google Scholar ]
• Illiger P., Schmidt G., Walde I., Hese S., Kudrjavzev A.E., Kurepina N. Estimation of regional soil organic carbon stocks merging classified land-use information with detailed soil data. Sci. Total Environ. 2019; 695 [ PubMed ] [ Google Scholar ]
• Imhof M.P., Heemskerk G.E., Cox M.T. Soil information management and knowledge sharing in Victoria, Australia—user perspectives. Soil Use Manag. 2019; 35 :39–51. [ Google Scholar ]
• Inam A., Adamowski J., Prasher S., Halbe J., Malard J., Albano R. Coupling of a distributed stakeholder-built system dynamics socio-economic model with SAHYSMOD for sustainable soil salinity management–part 1: model development. J. Hydrol. 2017; 551 :596–618. [ Google Scholar ]
• Ingram J., Mills J. Are advisory services “fit for purpose” to support sustainable soil management? An assessment of advice in Europe. Soil Use Manag. 2019; 35 :21–31. [ Google Scholar ]
• Janvier C., Villeneuve F., Alabouvette C., Edel-Hermann V., Mateille T., Steinberg C. Soil health through soil disease suppression: which strategy from descriptors to indicators? Soil Biol. Biochem. 2007; 39 :1–23. [ Google Scholar ]
• Jenkins A., Beange L., Morris S. Using webinars to extend the reach of soil learning in New South Wales: a first look. Soil Use Manag. 2019; 35 :52–62. [ Google Scholar ]
• Jia X., O’Connor D., Hou D., Jin Y., Li G., Zheng C. Groundwater depletion and contamination: spatial distribution of groundwater resources sustainability in China. Sci. Total Environ. 2019; 672 :551–562. [ PubMed ] [ Google Scholar ]
• Jia H., Hou D., O’Connor D., Pan S., Zhu J., Bolan N.S. Exogenous phosphorus treatment facilitates chelation-mediated cadmium detoxification in perennial ryegrass (Lolium perenne L.) J. Hazard. Mater. 2020; 389 [ PubMed ] [ Google Scholar ]
• Jing J., Christensen J.T., Sørensen P., Christensen B.T., Rubæk G.H. Long-term effects of animal manure and mineral fertilizers on phosphorus availability and silage maize growth. Soil Use Manag. 2019; 35 :323–333. [ Google Scholar ]
• Kahlon M.S., Lal R., Ann-Varughese M. Twenty two years of tillage and mulching impacts on soil physical characteristics and carbon sequestration in Central Ohio. Soil Tillage Res. 2013; 126 :151–158. [ Google Scholar ]
• Keesstra S.D., Bouma J., Wallinga J., Tittonell P., Smith P., Cerdà A. The significance of soils and soil science towards realization of the United Nations Sustainable Development Goals. Soil. 2016; 2 :111–128. doi: 10.5194/soil-2-111-2016. [ CrossRef ] [ Google Scholar ]
• Kell D.B. Large-scale sequestration of atmospheric carbon via plant roots in natural and agricultural ecosystems: why and how. Philosophical Transactions of the Royal Society B: Biological Sciences. 2012; 367 :1589–1597. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Khan S.U. Elsevier; 2016. Pesticides in the Soil Environment. [ Google Scholar ]
• Kibblewhite M., Ritz K., Swift M. Soil health in agricultural systems. Philosophical Transactions of the Royal Society B: Biological Sciences. 2008; 363 :685–701. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Klein J.T., Newell W.H. Handbook of the Undergraduate Curriculum: A Comprehensive Guide to Purposes, Structures, Practices, and Change. 1997. Advancing interdisciplinary studies; pp. 393–415. [ Google Scholar ]
• Knox O.G., Osanai Y., Polain K., Pereg L., Nachimuthu G., Wilson B. Lessons from extension activity related to cotton rotation impacts on soil—a scientist’s perspective. Soil Use Manag. 2019; 35 :141–149. [ Google Scholar ]
• Kota S., Giambene G. Proceedings of the Eleventh International Conference on Advances in Satellite and Space Communications-SPACOMM. 2019. Satellite 5G: IoT use case for rural areas applications; pp. 24–28. [ Google Scholar ]
• Krzywoszynska A. Making knowledge and meaning in communities of practice: what role may science play? The case of sustainable soil management in England. Soil Use Manag. 2019; 35 :160–168. [ Google Scholar ]
• Kumar V., Gathala M.K., Saharawat Y.S., Parihar C.M., Kumar R., Kumar R. Impact of tillage and crop establishment methods on crop yields, profitability and soil physical properties in rice–wheat system of indo-Gangetic Plains of India. Soil Use Manag. 2019; 35 :303–313. [ Google Scholar ]
• Kunhikrishnan A., Thangarajan R., Bolan N., Xu Y., Mandal S., Gleeson D. Functional relationships of soil acidification, liming, and greenhouse gas flux. Adv. Agron. 2016; 139 :1–71. Elsevier. [ Google Scholar ]
• Lafond G.P., Walley F., May W., Holzapfel C. Long term impact of no-till on soil properties and crop productivity on the Canadian prairies. Soil Tillage Res. 2011; 117 :110–123. [ Google Scholar ]
• Laird D., Fleming P., Wang B., Horton R., Karlen D. Biochar impact on nutrient leaching from a Midwestern agricultural soil. Geoderma. 2010; 158 :436–442. [ Google Scholar ]
• Laird D.A., Fleming P., Davis D.D., Horton R., Wang B., Karlen D.L. Impact of biochar amendments on the quality of a typical Midwestern agricultural soil. Geoderma. 2010; 158 :443–449. [ Google Scholar ]
• Lal R. Soil erosion and the global carbon budget. Environ. Int. 2003; 29 :437–450. [ PubMed ] [ Google Scholar ]
• Lauber C.L., Hamady M., Knight R., Fierer N. Pyrosequencing-based assessment of soil pH as a predictor of soil bacterial community structure at the continental scale. Appl. Environ. Microbiol. 2009; 75 :5111–5120. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Lavelle P., Decaëns T., Aubert M., Sb Barot, Blouin M., Bureau F. Soil invertebrates and ecosystem services. Eur. J. Soil Biol. 2006; 42 :S3–S15. [ Google Scholar ]
• Le Quere C., Andrew R.M., Friedlingstein P., Sitch S., Hauck J., Pongratz J. Global carbon budget 2018. Earth System Science Data. 2018; 10 :2141–2194. [ Google Scholar ]
• Leff J.W., Jones S.E., Prober S.M., Barberan A., Borer E.T., Firn J.L. Consistent responses of soil microbial communities to elevated nutrient inputs in grasslands across the globe. Proc. Natl. Acad. Sci. U. S. A. 2015; 112 :10967–10972. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Lehmann J., Joseph S. Earthscan London; 2009. Biochar for Environmental Management. [ Google Scholar ]
• Li J., Liu Y., Hai X., Shangguan Z., Deng L. Dynamics of soil microbial C:N:P stoichiometry and its driving mechanisms following natural vegetation restoration after farmland abandonment. Sci. Total Environ. 2019; 693 [ PubMed ] [ Google Scholar ]
• Li X., Han H., Ning T., Shen Y., Lal R. Variations of SOC and MBC observed in an incubated brown loam soil managed under different tillage systems for 12 years. Soil Use Manag. 2019; 35 :585–594. [ Google Scholar ]
• Liu J., Li S., Ouyang Z., Tam C., Chen X. Ecological and socioeconomic effects of China’s policies for ecosystem services. Proc. Natl. Acad. Sci. U. S. A. 2008; 105 :9477–9482. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Lobry de Bruyn L.A. Learning opportunities: understanding farmers’ soil testing practice through workshop activities to improve extension support for soil health management. Soil Use Manag. 2019; 35 :128–140. [ Google Scholar ]
• Lochon I., Carrère P., Yvin J.-C., Houdusse-Lemenager D., Bloor J.M.G. Impacts of low-level liming on soil respiration and forage production in a fertilized upland grassland in Central France. Sci. Total Environ. 2019; 697 [ PubMed ] [ Google Scholar ]
• Ma L., Abuduwaili J., Li Y., Liu W. Anthropogenically disturbed potentially toxic elements in roadside topsoils of a suburban region of Bishkek, Central Asia. Soil Use Manag. 2019; 35 :283–292. [ Google Scholar ]
• Maguire R.O., Sims J.T. Soil testing to predict phosphorus leaching. J. Environ. Qual. 2002; 31 :1601–1609. [ PubMed ] [ Google Scholar ]
• Maia S.M.F., Gonzaga G.B.M., Silva LkdS, Lyra G.B., Gomes TcdA. Soil organic carbon temperature sensitivity of different soil types and land use systems in the Brazilian semi-arid region. Soil Use Manag. 2019; 35 :433–442. [ Google Scholar ]
• Maltas A., Kebli H., Oberholzer H.R., Weisskopf P., Sinaj S. The effects of organic and mineral fertilizers on carbon sequestration, soil properties, and crop yields from a long-term field experiment under a Swiss conventional farming system. Land Degrad. Dev. 2018; 29 :926–938. [ Google Scholar ]
• Manzoni S., Porporato A. Soil carbon and nitrogen mineralization: theory and models across scales. Soil Biol. Biochem. 2009; 41 :1355–1379. [ Google Scholar ]
• McInnes-Clarke S.K., Jenkins B.R., Rawson A., Murphy B.W. Sharing soil knowledge and evaluating progress in the New South Wales Soil Knowledge Network. Soil Use Manag. 2019; 35 :105–116. [ Google Scholar ]
• Mehra P., Baker J., Sojka R.E., Bolan N., Desbiolles J., Kirkham M.B. A review of tillage practices and their potential to impact the soil carbon dynamics. Adv. Agron. 2018; 150 :185–230. Elsevier. [ Google Scholar ]
• MEP . Ministry of Environmental Protection; Beijing, China: 2014. National Soil Contamination Survey Report. [ Google Scholar ]
• Mills J., Reed M., Skaalsveen K., Ingram J. The use of Twitter for knowledge exchange on sustainable soil management. Soil Use Manag. 2019; 35 :195–203. [ Google Scholar ]
• Montgomery D.R. Soil erosion and agricultural sustainability. Proc. Natl. Acad. Sci. U. S. A. 2007; 104 :13268–13272. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Montgomery D.R. Soil erosion and agricultural sustainability. Proc. Natl. Acad. Sci. 2007; 104 :13268–13272. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Morais R., Silva N., Mendes J., Adão T., Pádua L., López-Riquelme J. Mysense: a comprehensive data management environment to improve precision agriculture practices. Comput. Electron. Agric. 2019; 162 :882–894. [ Google Scholar ]
• Mossadeghi-Björklund M., Jarvis N., Larsbo M., Forkman J., Keller T. Effects of compaction on soil hydraulic properties, penetration resistance and water flow patterns at the soil profile scale. Soil Use Manag. 2019; 35 :367–377. [ Google Scholar ]
• Mugandani R., Mafongoya P. Behaviour of smallholder farmers towards adoption of conservation agriculture in Zimbabwe. Soil Use Manag. 2019; 35 (4):561–575. [ Google Scholar ]
• Nachimuthu G., Watkins M.D., Hulugalle N.R., Weaver T.B., Finlay L.A., McCorkell B.E. Leaching of dissolved organic carbon and nitrogen under cotton farming systems in a Vertisol. Soil Use Manag. 2019; 35 :443–452. [ Google Scholar ]
• Neher D.A. Role of nematodes in soil health and their use as indicators. J. Nematol. 2001; 33 :161. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Nielsen M.N., Winding A., Binnerup S. 2002. Microorganisms as Indicators of Soil Health. [ Google Scholar ]
• Obrist D., Agnan Y., Jiskra M., Olson C.L., Colegrove D.P., Hueber J. Tundra uptake of atmospheric elemental mercury drives Arctic mercury pollution. Nature. 2017; 547 :201. [ PubMed ] [ Google Scholar ]
• O’Connor D., Hou D. More haste, less speed in replenishing China’s groundwater. Nature. 2019; 569 :487. [ PubMed ] [ Google Scholar ]
• O’Connor D., Hou D., Ok Y.S., Song Y., Sarmah A., Li X. Sustainable in situ remediation of recalcitrant organic pollutants in groundwater with controlled release materials: a review. J. Control. Release. 2018; 283 :200–213. [ PubMed ] [ Google Scholar ]
• O’Connor D., Peng T., Li G., Wang S., Duan L., Mulder J. Sulfur-modified rice husk biochar: a green method for the remediation of mercury contaminated soil. Sci. Total Environ. 2018; 621 :819–826. [ PubMed ] [ Google Scholar ]
• O’Connor D., Peng T., Zhang J., Tsang D.C., Alessi D.S., Shen Z. Biochar application for the remediation of heavy metal polluted land: a review of in situ field trials. Sci. Total Environ. 2018; 619 :815–826. [ PubMed ] [ Google Scholar ]
• O’Connor D., Hou D., Ok Y.S., Mulder J., Duan L., Wu Q. Mercury speciation, transformation, and transportation in soils, atmospheric flux, and implications for risk management: a critical review. Environ. Int. 2019; 126 :747–761. [ PubMed ] [ Google Scholar ]
• O’Connor D., Pan S., Shen Z., Song Y., Jin Y., Wu W.-M. Microplastics undergo accelerated vertical migration in sand soil due to small size and wet-dry cycles. Environ. Pollut. 2019; 249 :527–534. [ PubMed ] [ Google Scholar ]
• O’Connor D., Hou D., Ok Y.S., Lanphear B.P. The effects of iniquitous lead exposure on health. Nature Sustainability. 2020; 3 :77–79. [ Google Scholar ]
• Oliver M.A., Gregory P. Soil, food security and human health: a review. Eur. J. Soil Sci. 2015; 66 :257–276. [ Google Scholar ]
• Oliver D.P., Li Y., Orr R., Nelson P., Barnes M., McLaughlin M.J. The role of surface charge and pH changes in tropical soils on sorption behaviour of per- and polyfluoroalkyl substances (PFASs) Sci. Total Environ. 2019; 673 :197–206. [ PubMed ] [ Google Scholar ]
• Ottoy S., Vanierschot L., Dondeyne S., Vancampenhout K., Hermy M., Van Orshoven J. The devil is in the detail: discrepancy between soil organic carbon stocks estimated from regional and local data sources in Flanders, Belgium. Soil Use Manag. 2019; 35 :421–432. [ Google Scholar ]
• Packer I.J., Chapman G.A., Lawrie J.W. On-ground extension of soil information to improve land management. Soil Use Manag. 2019; 35 :75–84. [ Google Scholar ]
• Paustian K., Lehmann J., Ogle S., Reay D., Robertson G.P., Smith P. Climate-smart soils. Nature. 2016; 532 :49–57. [ PubMed ] [ Google Scholar ]
• Pavan A.L.R., Ometto A.R. Ecosystem Services in Life Cycle Assessment: a novel conceptual framework for soil. Sci. Total Environ. 2018; 643 :1337–1347. [ PubMed ] [ Google Scholar ]
• Pimentel D., Harvey C., Resosudarmo P., Sinclair K., Kurz D., McNair M. Environmental and economic costs of soil erosion and conservation benefits. Science. 1995; 267 :1117–1123. [ PubMed ] [ Google Scholar ]
• Pulleman M., Creamer R., Hamer U., Helder J., Pelosi C., Peres G. Soil biodiversity, biological indicators and soil ecosystem services—an overview of European approaches. Curr. Opin. Environ. Sustain. 2012; 4 :529–538. [ Google Scholar ]
• Qi S., Luo J., O’Connor D., Wang Y., Hou D. A numerical model to optimize LNAPL remediation by multi-phase extraction. Sci. Total Environ. 2020; 718 [ PubMed ] [ Google Scholar ]
• Rafiq M.K., Bai Y., Aziz R., Rafiq M.T., Mašek O., Bachmann R.T. Biochar amendment improves alpine meadows growth and soil health in Tibetan plateau over a three year period. Sci. Total Environ. 2019:135296. [ PubMed ] [ Google Scholar ]
• Ramesh T., Bolan N.S., Kirkham M.B., Wijesekara H., Kanchikerimath M., Rao C.S. Soil organic carbon dynamics: impact of land use changes and management practices: a review. Adv. Agron. 2019; 156 :1–107. [ Google Scholar ]
• Repko A.F., Szostak R. SAGE Publications, Incorporated; 2020. Interdisciplinary Research: Process and Theory. [ Google Scholar ]
• Rinot O., Levy G.J., Steinberger Y., Svoray T., Eshel G. Soil health assessment: a critical review of current methodologies and a proposed new approach. Sci. Total Environ. 2019; 648 :1484–1491. [ PubMed ] [ Google Scholar ]
• Robinson D., Fraser I., Dominati E., Davíðsdóttir B., Jónsson J., Jones L. On the value of soil resources in the context of natural capital and ecosystem service delivery. Soil Sci. Soc. Am. J. 2014; 78 :685–700. [ Google Scholar ]
• Robinson N.J., Dahlhaus P.G., Wong M., MacLeod A., Jones D., Nicholson C. Testing the public–private soil data and information sharing model for sustainable soil management outcomes. Soil Use Manag. 2019; 35 :94–104. [ Google Scholar ]
• Rojas R.V., Achouri M., Maroulis J., Caon L. Healthy soils: a prerequisite for sustainable food security. Environ. Earth Sci. 2016; 75 :180. [ Google Scholar ]
• Rumpel C., Amiraslani F., Koutika L.-S., Smith P., Whitehead D., Wollenberg E. Put more carbon in soils to meet Paris climate pledges. Nature. 2018; 564 :32–34. [ PubMed ] [ Google Scholar ]
• Saikia R., Sharma S., Thind H.S., Singh Y. Tillage and residue management practices affect soil biological indicators in a rice-wheat cropping system in north-western India. Soil Use Manag. 2020; 36 :157–172. [ Google Scholar ]
• Sanchez P.A. Soil fertility and hunger in Africa. Science. 2002; 295 :2019–2020. [ PubMed ] [ Google Scholar ]
• Schuur E.A., Abbott B., Bowden W., Brovkin V., Camill P., Canadell J. Expert assessment of vulnerability of permafrost carbon to climate change. Clim. Chang. 2013; 119 :359–374. [ Google Scholar ]
• Schuur E.A., McGuire A.D., Schädel C., Grosse G., Harden J., Hayes D.J. Climate change and the permafrost carbon feedback. Nature. 2015; 520 :171–179. [ PubMed ] [ Google Scholar ]
• Schwenke G., Beange L., Cameron J., Bell M., Harden S. What soil information do crop advisors use to develop nitrogen fertilizer recommendations for grain growers in New South Wales, Australia? Soil Use Manag. 2019; 35 :85–93. [ Google Scholar ]
• Senbayram M., Saygan E.P., Chen R., Aydemir S., Kaya C., Wu D. Effect of biochar origin and soil type on the greenhouse gas emission and the bacterial community structure in N fertilised acidic sandy and alkaline clay soil. Sci. Total Environ. 2019; 660 :69–79. [ PubMed ] [ Google Scholar ]
• Shen Z., Jin F., O’Connor D., Hou D. Solidification/stabilization for soil remediation: an old technology with new vitality. Environmental Science & Technology. 2019; 53 :11615–11617. [ PubMed ] [ Google Scholar ]
• Song Y., Kirkwood N., Maksimovic C., Zhen X., O’Connor D., Jin Y. Nature based solutions for contaminated land remediation and brownfield redevelopment in cities: a review. Sci. Total Environ. 2019; 663 :568–579. [ PubMed ] [ Google Scholar ]
• Stoate C., Jones S., Crotty F., Morris C., Seymour S. Participatory research approaches to integrating scientific and farmer knowledge of soil to meet multiple objectives in the English east midlands. Soil Use Manag. 2019; 35 :150–159. [ Google Scholar ]
• Su C., Liu H., Wang S. A process-based framework for soil ecosystem services study and management. Sci. Total Environ. 2018; 627 :282–289. [ PubMed ] [ Google Scholar ]
• Tavares R.L.M., de Souza Z.M., Siqueira D.S., La Scala Júnior N., Panosso A.R., Campos M.C.C. Soil CO2 emission in sugarcane management systems. Acta Agriculturae Scandinavica, Section B—Soil & Plant Science. 2015; 65 :755–762. [ Google Scholar ]
• Teng M., Huang C., Wang P., Zeng L., Zhou Z., Xiao W. Impacts of forest restoration on soil erosion in the Three Gorges Reservoir area, China. Sci. Total Environ. 2019; 697 [ PubMed ] [ Google Scholar ]
• Tisdale S.L., Nelson W.L., Beaton J.D. Collier Macmillan Publishers; 1985. Soil Fertility and Fertilizers. [ Google Scholar ]
• Totsche K.U., Rennert T., Gerzabek M.H., Kögel-Knabner I., Smalla K., Spiteller M. Biogeochemical interfaces in soil: the interdisciplinary challenge for soil science. J. Plant Nutr. Soil Sci. 2010; 173 :88–99. [ Google Scholar ]
• Tulau M.J., McInnes-Clarke S.K., Yang X., McAlpine R.A., Karunaratne S.B., Zhu Q. The Warrumbungle post-fire recovery project—raising the profile of soils. Soil Use Manag. 2019; 35 :63–74. [ Google Scholar ]
• Ukalska-Jaruga A., Klimkowicz-Pawlas A., Smreczak B. Characterization of organic matter fractions in the top layer of soils under different land uses in Central-Eastern Europe. Soil Use Manag. 2019; 35 :595–606. [ Google Scholar ]
• UN . 2015. Transforming our World: The 2030 Agenda for Sustainable Development A/RES/70/1. [ Google Scholar ]
• UN . 2019. The Sustainable Development Goals Report, New York. [ Google Scholar ]
• UNCCD . 2017. Global Land Outlook. [ Google Scholar ]
• Van Bruggen A.H., Semenov A.M. In search of biological indicators for soil health and disease suppression. Appl. Soil Ecol. 2000; 15 :13–24. [ Google Scholar ]
• Vogel H.-J., Bartke S., Daedlow K., Helming K., Kögel-Knabner I., Lang B. A systemic approach for modeling soil functions. Soil. 2018; 4 :83. [ Google Scholar ]
• Wang J., Liu X., Li Y., Powell T., Wang X., Wang G. Microplastics as contaminants in the soil environment: a mini-review. Sci. Total Environ. 2019; 691 :848–857. [ PubMed ] [ Google Scholar ]
• Wang L., Hou D., Shen Z., Zhu J., Jia X., Ok Y.S. Field trials of phytomining and phytoremediation: a critical review of influencing factors and effects of additives. Crit. Rev. Environ. Sci. Technol. 2019:1–51. [ Google Scholar ]
• Wang L., Hou D., Cao Y., Ok Y.S., Tack F.M., Rinklebe J. Remediation of mercury contaminated soil, water, and air: a review of emerging materials and innovative technologies. Environ. Int. 2020; 134 [ PubMed ] [ Google Scholar ]
• Wang L., Li X., Tsang D.C., Jin F., Hou D. Green remediation of Cd and Hg contaminated soil using humic acid modified montmorillonite: immobilization performance under accelerated ageing conditions. J. Hazard. Mater. 2020:122005. [ PubMed ] [ Google Scholar ]
• Wang L., Ok Y.S., Tsang D.C., Alessi D.S., Rinklebe J., Wang H. New trends in biochar pyrolysis and modification strategies: feedstock, pyrolysis conditions, sustainability concerns and implications for soil amendment. Soil Use Manag. 2020 doi: 10.1111/sum.12592. (In Press) [ CrossRef ] [ Google Scholar ]
• Welten B.G., Ledgard S.F., Judge A.A., Sprosen M.S., McGowan A.W., Dexter M.M. Efficacy of different temperate pasture species to reduce nitrogen leaching from cattle urine applied in different seasons: a soil lysimeter study. Soil Use Manag. 2019; 35 :653–663. [ Google Scholar ]
• Wick A.F., Haley J., Gasch C., Wehlander T., Briese L., Samson-Liebig S. Network-based approaches for soil health research and extension programming in North Dakota, USA. Soil Use Manag. 2019; 35 :177–184. [ Google Scholar ]
• Wilcke W. Synopsis polycyclic aromatic hydrocarbons (PAHs) in soil—a review. J. Plant Nutr. Soil Sci. 2000; 163 :229–248. [ Google Scholar ]
• Wolfert S., Ge L., Verdouw C., Bogaardt M.-J. Big data in smart farming–a review. Agric. Syst. 2017; 153 :69–80. [ Google Scholar ]
• Woolf D., Amonette J.E., Street-Perrott F.A., Lehmann J., Joseph S. Sustainable biochar to mitigate global climate change. Nat. Commun. 2010; 1 :56. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Wu T., Ayres E., Bardgett R.D., Wall D.H., Garey J.R. Molecular study of worldwide distribution and diversity of soil animals. Proc. Natl. Acad. Sci. 2011; 108 :17720–17725. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Xiao J., Wang L., Deng L., Jin Z. Characteristics, sources, water quality and health risk assessment of trace elements in river water and well water in the Chinese Loess Plateau. Sci. Total Environ. 2019; 650 :2004–2012. [ PubMed ] [ Google Scholar ]
• Xu L., Wang M., Tian Y., Shi X., Shi Y., Yu Q. Changes in soil macropores: superposition of the roles of organic nutrient amendments and the greenhouse pattern in vegetable plantations. Soil Use Manag. 2019; 35 :412–420. [ Google Scholar ]
• Yagi K., Minami K. Effect of organic matter application on methane emission from some Japanese paddy fields. Soil science and plant nutrition. 1990; 36 :599–610. [ Google Scholar ]
• Ye L., Camps-Arbestain M., Shen Q., Lehmann J., Singh B., Sabir M. Biochar effects on crop yields with and without fertilizer: a meta-analysis of field studies using separate controls. Soil Use Manag. 2020; 36 :2–18. [ Google Scholar ]
• Yu H., Zha T., Zhang X., Ma L. Vertical distribution and influencing factors of soil organic carbon in the Loess Plateau, China. Sci. Total Environ. 2019; 693 [ PubMed ] [ Google Scholar ]
• Zhang W.-F., Z-x Dou, He P., Ju X.-T., Powlson D., Chadwick D. New technologies reduce greenhouse gas emissions from nitrogenous fertilizer in China. Proc. Natl. Acad. Sci. U. S. A. 2013; 110 :8375–8380. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Zhang Y., Hou D., O’Connor D., Shen Z., Shi P., Ok Y.S. Lead contamination in Chinese surface soils: source identification, spatial-temporal distribution and associated health risks. Crit. Rev. Environ. Sci. Technol. 2019; 49 (15) [ Google Scholar ]
• Zhang J., Hou D., Shen Z., Jin F., O’Connor D., Pan S. Effects of excessive impregnation, magnesium content, and pyrolysis temperature on MgO-coated watermelon rind biochar and its lead removal capacity. Environ. Res. 2020; 183 :109152. [ PubMed ] [ Google Scholar ]
• Zhang Y., O’Connor D., Xu W., Hou D. Blood lead levels among Chinese children: the shifting influence of industry, traffic, and e-waste over three decades. Environ. Int. 2020; 135 [ PubMed ] [ Google Scholar ]
• Zhao H., Ning P., Chen Y., Liu J., Ghaffar S.A., Xiaohong T. Effect of straw amendment modes on soil organic carbon, nitrogen sequestration and crop yield on the North-Central Plain of China. Soil Use Manag. 2019; 35 :511–525. [ Google Scholar ]

• Biology Article
• What Is Soil?

What Is Soil

An estimated 70 percent of the earth’s surface is covered with water, while the remaining 30 per cent constitutes land. The layer of the earth that is composed of soil and is influenced by the process of soil formation is called pedosphere. But what exactly is soil and what is soil made of?

What is Soil?

Technically, the soil is a mixture that contains minerals, organic matter, and living organisms. But broadly speaking, soil can refer to any loose sediment. Moreover, there are many types of soil that are distributed around the world and these are generally classified into the following:

Typically, the soil consists of 45% minerals, 50% empty spaces or voids and 5% organic matter. Furthermore, soil performs many important functions such as:

• Providing a growth medium for the plants
• Acts a modifier of the earth’s atmosphere
• One of the most crucial components of the biosphere
• Provides habitat for organisms

Also Read:  Soil Teeming

How is Soil Formed?

Soil is formed by weathering of rocks. Solid rock can weather away in one of the three ways into the soil, namely:

Mechanical Weathering

Chemical weathering, biological weathering.

This is commonly observed near the surface of the earth. Also called physical weathering, as this process is influenced by physical forces such as wind, water and temperature.

As the name suggests, chemical weathering occurs when rocks are broken down by chemical reactions. Often, such types of weathering can change the chemical composition of the soil.

Though not an actual weathering process, living organisms weaken and subsequently disintegrate rocks, often by initiating mechanical or chemical weathering. For instance, tree roots can grow into cracks in the rock, prying them apart and causing mechanical fractures. Microorganisms can secrete chemicals that can increase the rock’s susceptibility to weathering.

Also Read:  Soil Profile

Composition of Soil

The soil is composed of different components: 5% organic matter, 45% minerals, 20-30% different gases and 20-30% water. Therefore, the soil is known as a heterogeneous body. Given below is the composition of soil in detail:

Organic Matter

Organic substance is found in very small amounts in the soil. Plants and animals are the main sources of organic matter. Depending upon the decomposition stage, the organic matter is of the following three types:

• Completely decomposed organic matter
• Partially decomposed organic matter
• Undecomposed organic matter

Minerals are an important element of the soil. These are solid components composed of atoms. These occur naturally and have a fixed chemical composition. Olivine and feldspar are the main minerals present in the soil.

Gaseous Components

The air-filled pores of the soil contain the gaseous components. Nitrogen and oxygen present in the pores is generally the atmospheric air fixed by the microorganisms. However, the composition of carbon dioxide is higher due to the gas produced by microorganisms present in the soil.

The soil dissolves the minerals and nutrients in the water and transports it to different parts of the plants . These are essential for the growth and development of the plant.

Importance of Soil

Soil is an important element essential for the survival of living organisms. The importance of soil is mentioned below:

• The fertile soil helps in the growth and development of the plants. The plants thus produced are healthy and provide food, clothing, furniture, and medicines.
• It supports many life forms including bacteria, fungi, algae, etc. These microbes, in turn, maintain environmental balance by retaining the moisture and decaying the dead organisms.
• The topsoil supports certain life activities such as reproduction, hatching, nesting, breeding, etc. of a few organisms.
• The organic matter present in the soil increases the fertility of the soil which is responsible for the growth of the plants. It also contains certain minerals and elements that are necessary for the plants to carry out their cellular activities.
• Soil is used for making cups, utensils, tiles, etc. The contents in the soil such as gravel, clay and sand are used in the construction of homes, roads, buildings, etc.
• Useful mineral medicines such as calcium, iron, and other substances such as petroleum jelly for cosmetics are extracted from the soil.
• The soil absorbs the rainwater. This water is evaporated and released into the air during sunny days, making the atmosphere cooler.

Also Read:  Mineral Riches In The Soil

Thus we see how the soil is formed, what it is composed of and how it is important to different life forms.

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Essay on Save Soil

Students are often asked to write an essay on Save Soil in their schools and colleges. And if you’re also looking for the same, we have created 100-word, 250-word, and 500-word essays on the topic.

Let’s take a look…

100 Words Essay on Save Soil

Introduction.

Soil is a vital part of our environment. It supports plant life, which provides us with food, oxygen, and more.

Soil Erosion

Soil erosion is a major issue. It happens when wind or water carry away the top layer of soil. This can lead to less fertile land.

Importance of Saving Soil

Saving soil is crucial. It helps maintain biodiversity, supports agriculture and fights climate change.

Ways to Save Soil

We can save soil by reducing deforestation, practicing sustainable farming, and controlling pollution. These actions will ensure healthy soil for future generations.

Also check:

• Paragraph on Save Soil

250 Words Essay on Save Soil

Soil, an indispensable component of our ecosystem, plays a pivotal role in maintaining the planet’s ecological balance. Despite its crucial role, soil degradation is a growing concern, demanding immediate attention and action.

The Importance of Soil

Soil is the foundation of agriculture, facilitating the growth of plants which provide us food, fiber, medicinal plants, and other essentials. It acts as a natural filter, purifying water before it reaches groundwater reserves. Moreover, soil sequesters carbon, helping mitigate climate change.

Threats to Soil

Various anthropogenic activities, including deforestation, industrialization, and unsustainable farming practices, have accelerated soil erosion and degradation. These activities disrupt the soil’s natural structure, leading to loss of fertility and biodiversity.

Soil Conservation

Effective soil conservation strategies are a necessity. Sustainable farming practices like crop rotation, contour ploughing, and agroforestry can be instrumental in preserving soil health. Policies promoting responsible land use and discouraging deforestation can also contribute significantly.

Role of Technology

Emerging technologies can aid in soil conservation. Satellite imagery and AI can help monitor soil health, predict erosion patterns, and guide sustainable land use. These technologies can empower farmers, policymakers, and researchers to make informed decisions.

Soil conservation is not just an environmental concern, but a matter of global food security and climate change mitigation. It is high time we acknowledge the importance of soil and take collective action to save it. After all, the health of soil is directly linked to the health of our planet and its inhabitants.

500 Words Essay on Save Soil

Soil, the thin layer of material covering our planet’s surface, plays a crucial role in sustaining life on Earth. It is a complex ecosystem that supports plant growth, regulates water flow, and acts as a habitat for billions of organisms. However, soil degradation, primarily caused by human activities, is threatening this vital resource. The need to save soil is more pressing than ever before.

Soil is a cornerstone of biodiversity, serving as a home to a myriad of organisms, from bacteria and fungi to insects and small mammals. These organisms contribute to the nutrient cycle, breaking down organic matter into nutrients that plants can absorb. In turn, these plants provide food and oxygen for animals and humans. Soil also plays a critical role in climate regulation. It stores carbon, reducing the amount of carbon dioxide in the atmosphere and mitigating climate change.

Despite its importance, soil is under threat from various human activities. Industrial agriculture, deforestation, and urbanization are leading causes of soil degradation. These practices strip the soil of its nutrients, disrupt its structure, and lead to erosion. Moreover, the use of synthetic fertilizers and pesticides can harm the soil’s microbiome, reducing its fertility and resilience.

Soil Conservation Strategies

To save soil, it is essential to implement sustainable land management practices. These include crop rotation, which helps maintain soil fertility by alternating the types of crops grown in a particular area, reducing the risk of pest and disease outbreaks. Cover cropping is another effective strategy; it prevents soil erosion, improves soil health, and enhances water retention.

Moreover, reducing the use of harmful chemicals in agriculture and promoting organic farming can significantly improve soil health. Organic farming encourages biodiversity, improves soil structure, and enhances its ability to retain water and nutrients.

Role of Education and Policy

Education plays a crucial role in soil conservation. By raising awareness about the importance of soil and the threats it faces, we can encourage more sustainable practices. In addition, policy interventions are needed to promote soil-friendly practices. Governments should incentivize sustainable farming and land use practices, and penalize those that contribute to soil degradation.

Soil is not just dirt beneath our feet; it’s a living, breathing ecosystem that sustains life on Earth. Our survival depends on its health. Therefore, saving soil should be a global priority. By adopting sustainable practices, educating people about the importance of soil, and implementing soil-friendly policies, we can ensure that this precious resource continues to support life for generations to come.

That’s it! I hope the essay helped you.

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• Essay on How to Prevent Soil Erosion
• Essay on Body Shaming

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Essay on Importance of Soil

January 21, 2018 by Study Mentor Leave a Comment

The life supporting natural resource which is formed by mixing of weathered rock materials and   decomposed biomass consisting of organic matter is called soil. It is one of the important natural resources. Soil is the most essential element of existence of life on earth.

Soil is the living ecosystem. Without soil, there is no existence of life.  In our Vedas, it is said that life form on this earth consists of five elements and soil is one of them.

So, creation of life form belongs to soil, development of life form belongs to soil, destruction of life form belongs to soil.

“If a healthy soil is full of death, it is also full of life.”

Table of Contents

Formation of soil

Rocks are the chief sources for the parent materials over which soil formation takes place. Rocks are converted into parent materials by the weathering process. In other words, weathering process precedes the soil formation. Parent materials include rocks, loses, alluvium, sand etc.

Weathering process means the physical and chemical deterioration of rocks over time due to factors like temperature, heat, pressure, water, wind etc. It takes more than thousand years for the formation of just one-inch layer of soil.

Components of soil

Soil contains different kinds of components. The components are given below

Air- In between the spaces of soil particles air is present. Soil with loose surface allows air diffusion in to it. Air contains gases like carbon dioxide, nitrogen, oxygen etc. Concentration of carbon dioxide is more than other gases.

Water- Water is the solution of organic and inorganic compounds. Soil contains water as it contains both organic and inorganic materials. Soil with more number of pores contain more water as water is absorbed in those pores.

Minerals- During weathering process, disintegration of rocks occurs. At that time particles of minerals are formed inside the soil.

Organic matters- These are the decayed form of organic substances like plants, animals, micro-organisms on the soil. These kinds of substances increase the fertility of the soil.

Micro-organisms- Micro -organisms like bacteria, fungi, algae are present in high numbers in the soil. These organisms act as decomposers of plants, animals, other organisms.

The above all components make soil suitable for existence and development of life form.

Soil as life

“The soil is the great connector of lives, the source and destination of all. It is the healer and restorer and   resurrect or, by which disease passes into health, age into youth, death into life. Without proper care for it we have no community, because without proper care for it we have no life”   -Wendell Berry

So, the existence of life form on this earth solely depends on soil. It forms the surface and ecosystem of the earth.

Image Credit: Source

As we early stated that soil is the living ecosystem. Soil is the habitat of all kinds of organisms. Different kinds of bacteria, fungi, algae, protozoa and undiscovered microbes acting as decomposes are found in high numbers in soil.

These micro-organisms decompose dead plant and animal bodies. As a result, pollution due to decaying dead bodies of animals decreases and it increases the quantity of organic matters in soil which makes the soil more fertile suitable for cultivation.

Soil is the natural medium for plant growth. Soil contains air which consists of gases like carbon dioxide, oxygen, nitrogen. For plant growth air ventilation is needed. So, soil provides oxygen, air ventilation for plant to grow. Water is also a major component of soil.

For plant growth water is important as it act as nutrient carrier and a main factor of plant life. Soil also contains minerals like silicon, aluminium, phosphorous, magnesium, carbon, iron, nitrogen etc. which are important elements.

Non-renewable resources like coal, petroleum, gold, copper, silver are found inside the earth. The modern world is standstill without these resources. These resources have become the integrated part of our life.

Soil holds the souvenir of our past and our cultural heritage buried in it. Soil plays a vital role as carbon reservoir as it absorbs most of the carbon dioxide gas and reduces the greenhouse gas concentration to some extent. Soil decomposes the dead bodies of plants and animals but it preserves their existence in the form of fossil.

For us food, cloth, and house are basic needs of life. Soil is the origin for all the three needs. When there is no soil, there is no food, no cloth, no house.

“Heaven is under our feet as well as over our heads.”    -Thoreau

Soil conservation

As soil is the origin of existence and development of life form on earth, conservation of it is must. Because without soil the whole living process is unthinkable. As earlier stated above that one-inch layer of soil formation takes more than thousand years.

Soil erosion mainly takes place due to water, wind, fertilizers etc. Heavy flow of water and heavy rainfall washes away the soil from one place to another. When there is no cover of plants, wind causes soil erosion. Loss of minerals, nutrients in soil as a result of utilization of fertilizers makes a steep erosion. Deforestation holds another cause.

Roots of trees hold the soil in a compact manner.  Litter of leaves resists soil erosion caused by wind and heavy rainfall. So, deforestation enhances the process of erosion.

Soil conservation includes following process

• Afforestation prevails erosion by reducing the velocity of wind and the roots held the soil in a strong manner.
• Growing of vegetation cover on the ground conserves soil.
• Crop rotation shoots up the productivity of the lands.
• Slowing down the water movement along the slope.
• Reduction in the usage of fertilizers, pesticides.
• Protection of soil from the strike of heavy water drops.

“Soil is a resource, a living, breathing entity that, if treated properly will maintain itself. When it has finally been depleted, the human population will disappear… project your imagination into the soil below you next time you go into the garden.

Think with compassion of the life that exists there. Think the drama, the sexuality, the harvesting, the work that carries on ceaselessly.”

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• Solar Eclipse 2024

What the World Has Learned From Past Eclipses

C louds scudded over the small volcanic island of Principe, off the western coast of Africa, on the afternoon of May 29, 1919. Arthur Eddington, director of the Cambridge Observatory in the U.K., waited for the Sun to emerge. The remains of a morning thunderstorm could ruin everything.

The island was about to experience the rare and overwhelming sight of a total solar eclipse. For six minutes, the longest eclipse since 1416, the Moon would completely block the face of the Sun, pulling a curtain of darkness over a thin stripe of Earth. Eddington traveled into the eclipse path to try and prove one of the most consequential ideas of his age: Albert Einstein’s new theory of general relativity.

Eddington, a physicist, was one of the few people at the time who understood the theory, which Einstein proposed in 1915. But many other scientists were stymied by the bizarre idea that gravity is not a mutual attraction, but a warping of spacetime. Light itself would be subject to this warping, too. So an eclipse would be the best way to prove whether the theory was true, because with the Sun’s light blocked by the Moon, astronomers would be able to see whether the Sun’s gravity bent the light of distant stars behind it.

Two teams of astronomers boarded ships steaming from Liverpool, England, in March 1919 to watch the eclipse and take the measure of the stars. Eddington and his team went to Principe, and another team led by Frank Dyson of the Greenwich Observatory went to Sobral, Brazil.

Totality, the complete obscuration of the Sun, would be at 2:13 local time in Principe. Moments before the Moon slid in front of the Sun, the clouds finally began breaking up. For a moment, it was totally clear. Eddington and his group hastily captured images of a star cluster found near the Sun that day, called the Hyades, found in the constellation of Taurus. The astronomers were using the best astronomical technology of the time, photographic plates, which are large exposures taken on glass instead of film. Stars appeared on seven of the plates, and solar “prominences,” filaments of gas streaming from the Sun, appeared on others.

Eddington wanted to stay in Principe to measure the Hyades when there was no eclipse, but a ship workers’ strike made him leave early. Later, Eddington and Dyson both compared the glass plates taken during the eclipse to other glass plates captured of the Hyades in a different part of the sky, when there was no eclipse. On the images from Eddington’s and Dyson’s expeditions, the stars were not aligned. The 40-year-old Einstein was right.

“Lights All Askew In the Heavens,” the New York Times proclaimed when the scientific papers were published. The eclipse was the key to the discovery—as so many solar eclipses before and since have illuminated new findings about our universe.

To understand why Eddington and Dyson traveled such distances to watch the eclipse, we need to talk about gravity.

Since at least the days of Isaac Newton, who wrote in 1687, scientists thought gravity was a simple force of mutual attraction. Newton proposed that every object in the universe attracts every other object in the universe, and that the strength of this attraction is related to the size of the objects and the distances among them. This is mostly true, actually, but it’s a little more nuanced than that.

On much larger scales, like among black holes or galaxy clusters, Newtonian gravity falls short. It also can’t accurately account for the movement of large objects that are close together, such as how the orbit of Mercury is affected by its proximity the Sun.

Albert Einstein’s most consequential breakthrough solved these problems. General relativity holds that gravity is not really an invisible force of mutual attraction, but a distortion. Rather than some kind of mutual tug-of-war, large objects like the Sun and other stars respond relative to each other because the space they are in has been altered. Their mass is so great that they bend the fabric of space and time around themselves.

Read More: 10 Surprising Facts About the 2024 Solar Eclipse

This was a weird concept, and many scientists thought Einstein’s ideas and equations were ridiculous. But others thought it sounded reasonable. Einstein and others knew that if the theory was correct, and the fabric of reality is bending around large objects, then light itself would have to follow that bend. The light of a star in the great distance, for instance, would seem to curve around a large object in front of it, nearer to us—like our Sun. But normally, it’s impossible to study stars behind the Sun to measure this effect. Enter an eclipse.

Einstein’s theory gives an equation for how much the Sun’s gravity would displace the images of background stars. Newton’s theory predicts only half that amount of displacement.

Eddington and Dyson measured the Hyades cluster because it contains many stars; the more stars to distort, the better the comparison. Both teams of scientists encountered strange political and natural obstacles in making the discovery, which are chronicled beautifully in the book No Shadow of a Doubt: The 1919 Eclipse That Confirmed Einstein's Theory of Relativity , by the physicist Daniel Kennefick. But the confirmation of Einstein’s ideas was worth it. Eddington said as much in a letter to his mother: “The one good plate that I measured gave a result agreeing with Einstein,” he wrote , “and I think I have got a little confirmation from a second plate.”

The Eddington-Dyson experiments were hardly the first time scientists used eclipses to make profound new discoveries. The idea dates to the beginnings of human civilization.

Careful records of lunar and solar eclipses are one of the greatest legacies of ancient Babylon. Astronomers—or astrologers, really, but the goal was the same—were able to predict both lunar and solar eclipses with impressive accuracy. They worked out what we now call the Saros Cycle, a repeating period of 18 years, 11 days, and 8 hours in which eclipses appear to repeat. One Saros cycle is equal to 223 synodic months, which is the time it takes the Moon to return to the same phase as seen from Earth. They also figured out, though may not have understood it completely, the geometry that enables eclipses to happen.

The path we trace around the Sun is called the ecliptic. Our planet’s axis is tilted with respect to the ecliptic plane, which is why we have seasons, and why the other celestial bodies seem to cross the same general path in our sky.

As the Moon goes around Earth, it, too, crosses the plane of the ecliptic twice in a year. The ascending node is where the Moon moves into the northern ecliptic. The descending node is where the Moon enters the southern ecliptic. When the Moon crosses a node, a total solar eclipse can happen. Ancient astronomers were aware of these points in the sky, and by the apex of Babylonian civilization, they were very good at predicting when eclipses would occur.

Two and a half millennia later, in 2016, astronomers used these same ancient records to measure the change in the rate at which Earth’s rotation is slowing—which is to say, the amount by which are days are lengthening, over thousands of years.

By the middle of the 19 th century, scientific discoveries came at a frenetic pace, and eclipses powered many of them. In October 1868, two astronomers, Pierre Jules César Janssen and Joseph Norman Lockyer, separately measured the colors of sunlight during a total eclipse. Each found evidence of an unknown element, indicating a new discovery: Helium, named for the Greek god of the Sun. In another eclipse in 1869, astronomers found convincing evidence of another new element, which they nicknamed coronium—before learning a few decades later that it was not a new element, but highly ionized iron, indicating that the Sun’s atmosphere is exceptionally, bizarrely hot. This oddity led to the prediction, in the 1950s, of a continual outflow that we now call the solar wind.

And during solar eclipses between 1878 and 1908, astronomers searched in vain for a proposed extra planet within the orbit of Mercury. Provisionally named Vulcan, this planet was thought to exist because Newtonian gravity could not fully describe Mercury’s strange orbit. The matter of the innermost planet’s path was settled, finally, in 1915, when Einstein used general relativity equations to explain it.

Many eclipse expeditions were intended to learn something new, or to prove an idea right—or wrong. But many of these discoveries have major practical effects on us. Understanding the Sun, and why its atmosphere gets so hot, can help us predict solar outbursts that could disrupt the power grid and communications satellites. Understanding gravity, at all scales, allows us to know and to navigate the cosmos.

GPS satellites, for instance, provide accurate measurements down to inches on Earth. Relativity equations account for the effects of the Earth’s gravity and the distances between the satellites and their receivers on the ground. Special relativity holds that the clocks on satellites, which experience weaker gravity, seem to run slower than clocks under the stronger force of gravity on Earth. From the point of view of the satellite, Earth clocks seem to run faster. We can use different satellites in different positions, and different ground stations, to accurately triangulate our positions on Earth down to inches. Without those calculations, GPS satellites would be far less precise.

This year, scientists fanned out across North America and in the skies above it will continue the legacy of eclipse science. Scientists from NASA and several universities and other research institutions will study Earth’s atmosphere; the Sun’s atmosphere; the Sun’s magnetic fields; and the Sun’s atmospheric outbursts, called coronal mass ejections.

When you look up at the Sun and Moon on the eclipse , the Moon’s day — or just observe its shadow darkening the ground beneath the clouds, which seems more likely — think about all the discoveries still yet waiting to happen, just behind the shadow of the Moon.

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What Solar Eclipse-Gazing Has Looked Like for the Past 2 Centuries

Millions of people on Monday will continue the tradition of experiencing and capturing solar eclipses, a pursuit that has spawned a lot of unusual gear.

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By Sarah Eckinger

• April 8, 2024

For centuries, people have been clamoring to glimpse solar eclipses. From astronomers with custom-built photographic equipment to groups huddled together with special glasses, this spectacle has captivated the human imagination.

Creating a Permanent Record

In 1860, Warren de la Rue captured what many sources describe as the first photograph of a total solar eclipse . He took it in Rivabellosa, Spain, with an instrument known as the Kew Photoheliograph . This combination of a telescope and camera was specifically built to photograph the sun.

Forty years later, Nevil Maskelyne, a magician and an astronomy enthusiast, filmed a total solar eclipse in North Carolina. The footage was lost, however, and only released in 2019 after it was rediscovered in the Royal Astronomical Society’s archives.

Telescopic Vision

For scientists and astronomers, eclipses provide an opportunity not only to view the moon’s umbra and gaze at the sun’s corona, but also to make observations that further their studies. Many observatories, or friendly neighbors with a telescope, also make their instruments available to the public during eclipses.

Fredrik Hjalmar Johansen, Fridtjof Nansen and Sigurd Scott Hansen observing a solar eclipse while on a polar expedition in 1894 .

Women from Wellesley College in Massachusetts and their professor tested out equipment ahead of their eclipse trip (to “catch old Sol in the act,” as the original New York Times article phrased it) to New London, Conn., in 1922.

A group from Swarthmore College in Pennsylvania traveled to Yerbaniz, Mexico, in 1923, with telescopes and a 65-foot camera to observe the sun’s corona .

Dr. J.J. Nassau, director of the Warner and Swasey Observatory at Case School of Applied Science in Cleveland, prepared to head to Douglas Hill, Maine, to study an eclipse in 1932. An entire freight car was required to transport the institution’s equipment.

Visitors viewed a solar eclipse at an observatory in Berlin in the mid-1930s.

A family set up two telescopes in Bar Harbor, Maine, in 1963. The two children placed stones on the base to help steady them.

An astronomer examined equipment for an eclipse in a desert in Mauritania in June 1973. We credit the hot climate for his choice in outfit.

Indirect Light

If you see people on Monday sprinting to your local park clutching pieces of paper, or with a cardboard box of their head, they are probably planning to reflect or project images of the solar eclipse onto a surface.

Cynthia Goulakos demonstrated a safe way to view a solar eclipse , with two pieces of cardboard to create a reflection of the shadowed sun, in Lowell, Mass., in 1970.

Another popular option is to create a pinhole camera. This woman did so in Central Park in 1963 by using a paper cup with a small hole in the bottom and a twin-lens reflex camera.

Amateur astronomers viewed a partial eclipse, projected from a telescope onto a screen, from atop the Empire State Building in 1967 .

Back in Central Park, in 1970, Irving Schwartz and his wife reflected an eclipse onto a piece of paper by holding binoculars on the edge of a garbage basket.

Children in Denver in 1979 used cardboard viewing boxes and pieces of paper with small pinholes to view projections of a partial eclipse.

A crowd gathered around a basin of water dyed with dark ink, waiting for the reflection of a solar eclipse to appear, in Hanoi, Vietnam, in 1995.

Staring at the Sun (or, How Not to Burn Your Retinas)

Eclipse-gazers have used different methods to protect their eyes throughout the years, some safer than others .

In 1927, women gathered at a window in a building in London to watch a total eclipse through smoked glass. This was popularized in France in the 1700s , but fell out of favor when physicians began writing papers on children whose vision was damaged.

Another trend was to use a strip of exposed photographic film, as seen below in Sydney, Australia, in 1948 and in Turkana, Kenya, in 1963. This method, which was even suggested by The Times in 1979 , has since been declared unsafe.

Solar eclipse glasses are a popular and safe way to view the event ( if you use models compliant with international safety standards ). Over the years there have been various styles, including these large hand-held options found in West Palm Beach, Fla., in 1979.

Parents and children watched a partial eclipse through their eclipse glasses in Tokyo in 1981.

Slimmer, more colorful options were used in Nabusimake, Colombia, in 1998.

In France in 1999.

And in Iran and England in 1999.

And the best way to see the eclipse? With family and friends at a watch party, like this one in Isalo National Park in Madagascar in 2001.