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Soil Erosion Problems and Solutions

Soil Degradation

An Introduction to U.S. Soil Conservation Programs

Soil. It’s underfoot, where food is grown, and the foundation on which homes, roads, and important infrastructure are built. Wind and water soil erosion poses serious consequences to land, crops, vegetation, and human health. During erosion and runoff, sediment might be carried into the air or deposited downstream or on roadways. Infrastructure is compromised and pollutants are distributed. 

The effects of the growing agriculture industry on United States land prompted the U.S. government to implement programs and acts that work to conserve and preserve soil from erosion and degradation. Since the 1930s, the United States has expanded its various conservation programs in order to utilize the land to its full potential while reducing the harm caused by human activities such as agriculture. 

Today, several federal soil conservation programs operate under the United States Department of Agriculture and a USDA conservation service, the National Resources Conservation Service (NRCS). This program oversees the programs designed by the USDA, and with contribution from the U.S. Forest Service, to reduce the impact of soil erosion while making preservation efforts in the Great Plains and on U.S. wetlands.

History of Conservation Programs

The U.S. government has implemented programs to combat soil erosion caused by humans. Many of these acts focus on sustainable farming and agriculture.

1935 Soil Conservation Act: Congress enacted this program in order to “…provide for the protection of land resources against soil erosion, and for other purposes.” This act authorized the Conservation Options Program and the voluntary Soil Conservation Service, the predecessor to NRCS. These offshoots provided technical assistance to those looking to implement soil management programs and reduce the harmful effects of agriculture.

1936 Soil Conservation and Domestic Allotment Act: U.S. federal policy amended the Soil Conservation Act to encourage participation in agricultural conservation programs. This gave rise to the Agricultural Conservation Program, a voluntary program that provides producers the financial assistance they might require to put into use approved conservation practices

1956 Great Plains Conservation Program (GPCP): This voluntary long-term program sought to address the issues of soil erosion from wind and water, specifically on the Great Plains — an area of prime agriculture real estate. Producers were encouraged to adopt conservation practices to reduce erosion and employ best practices for the use of water and soil resources. Functions of this program included “anti-pollution practices, measures to enhance fish, wildlife, and recreation resources, and practices to promote economic land use.”

1956-today: The NRCS has greatly expanded in the years following, and today there are approximately two dozen programs designed to assist producers by providing education, and technical and financial assistance to implement conservation practices.

At the heart of these programs lie common goals:

  • Address natural resource and environmental concerns associated with agriculture.
  • Reduce soil erosion.
  • Enhance water supplies.
  • Improve water quality.
  • Increase wildlife habitat.
  • Reduce damages from floods and natural disasters.

Major Programs Today

Today, soil conservation programs are divided into two major categories: Working Land and Land Retirement. In the case of working-land programs, conservation practices are put into use on productive agricultural land. Under these programs, the land must stay in active production for the entirety of its enrollment period.

Land Retirement programs require that certain land is removed from agricultural production due to its vulnerability or high-erosion risk. Land sent into retirement then adopts conservation practices designated under the program the land is enrolled in.

Up until 2000, 90% of conservation programs focused on land retirement. Since then, the focus of the NRCS has shifted with the realization that working land needs as much, or more, protections.

Conservation Reserve Program (CRP)

This land retirement program serves to remove millions of acres of sensitive land that is susceptible to erosion from agricultural production. With 27 million acres lost to soil erosion, this program aims to reduce the damaging effects caused by agricultural production. Under this soil conservation service resides the Farm Service Agency which administers CRP in 10-year contracts under the NRCS.

Agricultural Conservation Easement Program (ACEP)

A working land program, the ACEP provides financial and technical assistance for agricultural land and wetlands to promote their conservation and the benefits both provide.

Also under this program is the Agricultural Land Easements. This component assists the NRCS in promoting Native American tribes, state and local governments, and non-government organizations to protect working land and prevent non-agricultural use of said land. The Wetlands Reserve Easements is yet another component that works to restore, protect, and enhance wetlands.

Environmental Quality Incentives Program (EQIP)

Another working-land program, EQIP may provide cost-share payments to producers and landowners to encourage them to put into place management practices to conserve and protect. Under this program reside four other programs with focused intent, which include the Conservation Innovative Grants, Ground and Surface Water Conservation, Klamath River Basin, and Colorado River Basin Salinity Control programs

The Conservation Security Program (CSP)

This working lands program offers financial incentives and technical assistance to agricultural producers. The program rewards producers who promote conservation efforts and work to improve soil, water, air, energy, plant, and animal life. This program is one of the most promising as it could eventually affect US agricultural policy.

Since the 1930s, and not that far into the 20th century, the U.S. recognized that just as the environment affected agriculture, so agriculture affected the environment. The implementation of several soil conservation programs under USDA oversight illustrate the efforts that need to be made to prevent or at least minimize the damage of soil erosion. 

World population has more than tripled since 1935, with now over seven billion humans on the planet that are fed and clothed through agriculture. As changing weather patterns produce storms and create unpredictability, agricultural producers and landowners must be more vigilant than ever.

Today there are many more programs filled with incentives and education to raise awareness and promote conservation efforts, a step in the right direction. Manufacturers are fulfilling the demand for substrates and sod-forming material to combat erosion and runoff. The National Resources Conservation Program has made strides forward to minimize the damage from soil erosion to include working land and land sent into retirement equally in the efforts to combat the effects of human activity and growth.

The Causes and Effects of Soil Compaction

Soil is the foundation on which everything else is built. Life and the experience of life need soil to grow, prosper, and create. Soil is responsible for growing food, nutrients, and shelter while it provides a foundation for homes, roads, and buildings. When soil is stable and of excellent quality, air and water circulate for maximum plant growth, erosion is minimal, and insects and microbes make their homes where they are most beneficial. Soil compaction has both positive and negative implications depending on how and why the soil was compacted. While compaction might aid construction, it doesn’t bode well for crops and harvests.

Soil compaction is most often seen on farmland and areas where land is cultivated as heavy machinery passing over land presses soil into itself. When people use heavy machinery, 70 to 80% of soil compaction takes place on the first pass. Yet the compression of soil has its benefits when used to the right advantage.

What is Soil Compaction?

When soil aggregates or particles are pressed together constantly and over time, soil compaction takes place. Soil compaction and its resulting issues must be considered when planting new crops, building roadways, or during restoration.

To illustrate soil compaction, consider a slice of bread. This slice of bread is probably full of varying sizes of holes that allow air and liquid to pass through. If the slice is squeezed until it gets doughy, the result is a lump that’s been smashed and pressed together to make it smaller and denser. This makes it much more difficult for air and liquid to penetrate. Compacted soil reacts the same way — heavy, dense, and less likely to absorb water or nutrients, which will starve roots.

Soil compaction presses soil particles together to reduce pore size. As soil pores are reduced, soil volume is affected and much less likely to drain, just as water rolls off the mushed slice of bread. When soil’s density is increased, infiltration slows and gas exchange is reduced, causing a reduction in soil nutrients and fertility.

Soil compaction also compromises soil strength. When the soil is dense and of low porosity, roots have a harder time digging down through compacted layers to take hold.

Effects of Soil Compaction

Soil compaction has far-reaching implications as it affects all stages of soil life. Burrowing animals may have difficulty creating a habitat from compacted soil which will impact soil formation. Compacted soil increases the likelihood of aeration problems that impacts rooting plants. The flow of nutrients may drastically slow and impact crop and harvest schedules.

Plants and animals aren’t the only ones who need nutrition; soil does as well. If the soil isn’t fed properly, it cannot feed roots properly. When a root tries to make its way through soil and reaches a depth it can no longer push through, it will grow in horizontally resulting in a pancake effect. This stunts the growth of the plant and minimizes its ability to draw water and nutrition from the soil. As one plant is affected, so are all. Crop yields may be drastically reduced due to soil compaction.

The structure of the soil is another essential factor in the effects of compaction. When soil structure is destabilized, compaction from external pressure is easier to achieve. Soils subject to heavy traffic are slower to warm when compared with less compacted soils.

Try reshaping the slice of bread from earlier. Although the slice might be formed back into a square shape, its integrity has forever been altered and it is no longer what it once was.

Causes of Soil Compaction

Soil compaction is most often seen when machinery or automobiles pass over the surface. Soil types also have an influence on compaction depending on their moisture level and the contents of the soil’s organic matter. Organic matter works with other elements to bind soil particles together. Areas of land susceptible to compaction might contain wet soil that is much more likely to bind and compact.

When is Soil Compaction Desired?

Soil compaction is sometimes an end result. Take for instance the case of infrastructures like roadways and bridges. Considering that compacted soil is often strengthened by making it heavier due to the force of pressing soil particles together, this makes it desirable as a base for something like a highway.

The soil under man-made structures must be stable and less likely to erode or otherwise be carried away. Housing is also where soil compaction is necessary and welcomed for a solid foundation where there will be less settling or disturbance of the underlying soil structure.

Machines such as vibrating rollers or compactors are designed for just this purpose. Proof rolling, or test rolling, is a method used to determine if the soil will bear the long-term impacts of compaction and construction. 

 Minimizing Compaction

Since wet soil is more easily compacted than dry, it is best to stay off saturated lands to avoid compressing the soil with machinery. Increasing water infiltration and storage ability by incorporating natural coir geotextiles to help soil drain and aerate efficiently. Create more efficient practices around planting and harvest to stay off the land as much as possible and allow for nature to work unobstructed.

Compaction can be tested with a simple test. Drive a stake into the ground where there is little to no machinery or heavy traffic. Note how far the stake can be driven and the number of strikes to drive it to that depth. Now do the same in areas where compaction is suspected. Note the number of strikes to drive the stake as well as its corresponding depth. Although it’s not foolproof, this method gives a rudimentary assessment of soil compaction.

Soil compaction can have its upside if it is part of the underlying foundation of concrete, asphalt, etc., to build homes and roadways, but when compaction takes place and interferes with growth and production, it becomes a problem. The good news is that soil compaction takes place primarily from human activity and human interventions can minimize its impact.

What is Land Degradation?

What is land degradation? Land degradation is a negative change in the quality of land, usually induced by a mixture of natural and man-made causes.

It affects the land’s topsoil, the vegetation that grows on it, and the nearby water sources. It is a global issue with millions of people being affected, even forcing them to relocate in some cases.

What Causes Land Degradation

In most cases, the main causes of land degradation are linked to one or more human activities. Deforestation is one of the most common activities that cause the degradation of land.

Forests play a big part in keeping the soil fertile by constantly feeding it with nutrients from fallen leaves and fruit, as well as from animal droppings. They also keep the soil’s structure in place with the help of the trees’ roots.

Therefore, cutting down a part of a forest is a clear path to land degradation.

Another major man-made cause of land degradation and development of unfertile soils is the overuse of pesticides and fertilizers. Although they have become indispensable to raising rich crops, excessive use is known to gravely deteriorate the affected land.

Certain natural nutrients within the soil become imbalanced as a result of overuse of fertilizers, with a negative long-term effect on the land. Good farming practices will always seek to balance the short-term gain of eliminating pests and growing bigger crops with the long-term downside of land degradation.

Overgrazing is another significant cause of land degradation. It usually occurs when livestock is fed on a limited patch of land and the grass and other vegetation in the area are not able to regenerate at a sufficient rate.

The resulting lack of vegetation deprives the land of much-needed nutrients, the result being the degradation of the soil. It is a major issue, especially in Africa, where the long-term grazing of livestock on small patches of land leads to rapid land degradation.

Salination is also a significant cause of land degradation. It’s defined by the increase of salt concentration in the soil; it can be either man-induced or a natural phenomenon.

A high salt concentration in water used for irrigation, excessive use of alkaline fertilizers, inadequate soil drainage, or simply the wind blowing the salt in areas near the sea are causes of land salination that leads to land degradation.

 “Land Degradation: Creation and Destruction,” by Douglas L. Johnson and Laurence A. Lewis, states that the main naturally induced causes of land degradation are wind and water erosion.

Wind erosion occurs in areas with little or no vegetation and sandy soil, so strong winds carrying soil particles deteriorate the land. Water erosion is the displacement of land either by water in motion or by heavy rains. It’s often caused by human actions like deforestation, but it can also occur naturally in situations such as heavy rain, causing soil displacement on a steep slope of land. 

Land Degradation Effects

The main effects of land degradation can be soil erosion, salinization, acidification, and alkalization of the land, and finally desertification. Land desertification is the most severe stage of land degradation. It means that a piece of land has lost all its vegetation, wildlife, and all its water supplies — it basically has been turned into a desert.

The first steps in recognizing the effects that land degradation has on the planet are understanding its causes and effects. Sadly, the effects can be felt all over the world. The countries that are most affected are usually the poorest, and the lack of crops and farmable land can lead to massive food shortages.

Also, as crops become less efficient, water sources also dry up, often leading to the mass migration of people to more hospitable lands.

The downward spiral caused by land degradation can lead to major socio-economic issues. As food and water become scarce, competition for the remaining resources increases.

In poor countries and isolated regions, this competition can often lead to a monopoly on vital resources, resulting in violent attempts to overturn such a monopoly.

Experts on land management Ephraim Nkonya, Alisher Mirzabaev, and Joachim von Braun, argue in their book, “Economics of Land Degradation and Improvement – A Global Assessment for Sustainable Development,” that degradation is also a significant health hazard to the populations in the affected areas.

Due to the relatively low standard of living in most such areas, the lack of food and water will often lead to malnutrition, as well as diseases caused by the lack of clean water and the resulting poor hygiene. If the population migrates, the risk spreads out, as certain infectious diseases can be carried by the migrating population to new lands.

How to Prevent Land Degradation

In order to prevent or reverse the effects of land degradation, a series of policies and management practices must be implemented. In areas where the degradation process is at its initial stages, it’s crucial that prevention practices are quickly put in place.

Prevention is significantly less expensive than trying to reverse the effects of land degradation. That’s why the first step in preventing land degradation is to properly inform the people in an endangered area about both the causes and effects of the phenomenon and also about the great danger of desertification.

As in most situations, properly preventing land desertification is a matter of avoiding the causes. Natural causes such as heavy rain or strong winds obviously cannot be avoided, but according to a report by the United Nations’ Economic and Social Commission for Western Asia on land degradation assessment and prevention, the man-made causes need to be better managed or eliminated in order to avoid land degradation. 

Deforestation must be kept to a minimum and always be followed by reforestation, in order to keep the land well bound and rich with the nutrients it needs.

Sustainable farming also needs to be practiced, with good management of the levels of pesticides and fertilizers used, as well as avoiding soil depletion because of overgrazing by livestock. 

Land degradation is an issue that should concern every country and every community. Although we have significantly evolved from a technological point of view, our survival still heavily relies on the quality of our lands, and that is especially true in poorer regions.

The decrease in soil quality not only affects agriculture but also creates a ripple effect of major socio-economic implications that affect the entire planet.

List of sources:

“Land Degradation: Creation and Destruction,”  Douglas L. Johnson, Laurence A. Lewis

“Economics of Land Degradation and Improvement – A Global Assessment for Sustainable Development,”  Ephraim Nkonya, Alisher Mirzabaev, Joachim von Braun

Land degradation assessment and prevention, United Nations Economic and Social Commission for Western Asia

Need to Know: Soil Degradation

The soil is a crucial component of agriculture and forestry, and degradation leads to a partial or total decline of its productive capacity. Due to natural hazards or human mismanagement, the soil can lose one or more of its potential ecological functions, leading to a steep decline in its capacity to be used in the production of goods and services.

Defining Soil Degradation

A 2004 report by the U.N. Department of Economic and Social Affairs described soil degradation as a process that occurs when “the balance between the attacking forces of climate and the natural resistance of the terrain against these forces has been broken by human intervention, resulting in a decreased current and/or future capacity of soil to support life”.

Soil degradation is primarily attributed to mismanagement or misuse of the land in domains such as agriculture, industry, or urban planning. Due to its major impact on food growth and consumption and on the environment as a whole, soil degradation causes have been a constant topic of research and concern throughout the 20th and the 21st centuries.

Causes of Soil Degradation

Throughout the world, soil degradation is usually caused by one or more of these three factors:

  • Physical factors represent the loss of the soil’s life-sustaining qualities due to natural physical forces, mainly water or wind erosion. These physical forces affect the structure of the soil mainly by damaging its top layer and subsequent organic matter, where the nutrients necessary for sustaining growth are found. Long-term exposure to massive rainfall, winds, floods, surface runoff, or any other powerful physical factors leads to the slow decline in the respective soil’s structure and quality. According to Volume 11 of the publication “Advances in Soil Science,” physical degradation can include:
    • Compaction and hardsetting, causing densification of soil due to the elimination or reduction of its structural pores, and also increasing soil’s bulk density as a result of natural and manmade factors.
    • Desertification caused by erosion and sedimentation due to constant exposure to wind and water.
    • Laterization, meaning the desiccation and hardening of plinthitic material.
  • Chemical factors are the alterations of the soil’s chemical properties that lead to it losing nutrients. University of Chittagong professor Khan Towhid Osman’s book, “Soil Degradation, Conservation and Remediation,” states that chemical degradation of soil can be caused by a number of factors, such as a rise of alkalinity or acidity levels, or simply the oversaturation of the respective soil with water. The result is usually either a buildup of salt or the hardening of the soil, with soil nutrients being irreversibly lost in the process. More than half a billion acres of land are affected by chemical soil erosion throughout the world. 
  • Biological factors refer to human activities or plant growth that cause degradation of soil quality by accentuation compaction, erosion, water runoff, anaerobiosis, nutrient depletion, reduction in SOC pool etc., as described in the book “Soil Degradation in the United States: Extent, Severity, and Trends.” An overaccumulation of fungi or bacteria can, for example, cause biochemical reactions that will drastically reduce the soil’s capacity to grow proper crops. Poor farming practices and overfarming also have the potential to diminish the fertility of the soil by depleting it of nutrients. These farming practices can be excessive cultivation, improper manuring, misuse or overuse of fertilizers, or excessive irrigation, among others. 

There are also other factors that can lead to soil degradation. Deforestation will dramatically alter the soil’s composition by removing the vegetation that binds it together. Mining and other industrial activities release toxic substances into the soil, making it poisonous and completely unusable. Also, urbanization will unavoidably affect the soil quality by covering the soil with concrete and with the inevitable rise in pollution levels.

Effects of Soil Degradation

The most significant effect of soil degradation is the loss of a land’s life-sustaining qualities. Throughout the world, more and more land becomes unusable because of factors like soil pollution, contamination, and erosion.

The overuse of fertilizers also keeps the affected land from regenerating, polluting both the land and water in the area and dramatically decreasing land value.

Another major effect of degradation to the soil is its contribution to droughts and the occurrence of arid conditions in certain areas. Soil degradation reduces the biodiversity in the area, leading to desertification and the inevitable drought and aridity that come with it.

The University of Sheffield’s Grantham Centre for Sustainable Futures estimates that approximately 40 percent of the world’s agricultural land is unusable because of the loss of soil quality caused by degradation and overuse of agrochemicals. These practices make agriculture impossible, and therefore make the respective land useless.

Due to the alteration of the degraded soil’s physical attributes, one of the consequences is the affected land’s inability to hold massive amounts of water, leading to increased chances of floods occurring.

How Big is the Range of Soil Degradation Observed Between Continents?

Soil degradation is a big issue all over the world, but Africa is by far the most-affected continent. Throughout the African continent, it is estimated that 28 percent of the land is affected by degradation.

This costs the continent as much as 56 billion euros every year. It’s usually manmade, with the lack of fertile land being compensated by mass deforestation, leading to massive soil degradation. It can be reversed, though, with massive state programs and policies that train communities to take better care of the land. 

Other areas of the world gravely affected by the degradation of soil are Southeast Asia, Northern and Central Australia, China, and parts of the boreal forests in North America and Siberia. 

Solutions for Soil Degradation

The reduction and reversal of soil degradation typically lie in the elimination of manmade causes. Chief among these causes is massive deforestation, and the trend can be reversed by educating populations and governments about the dangers of reckless deforestation. Improving the land’s organic composition and restoring its mineral matter can also reverse soil degradation.

Prevention is also crucial to reducing the amount of land that is affected by soil degradation. Reducing over-irrigation, improving overall irrigation efficiency, and preventing land salinization are all significantly more cost-effective than restoring soil that has already been affected by degradation.

Soil degradation is an issue that affects the entire world in numerous ways. It increases the odds of famine and poverty in already impoverished countries. It also increases the cost and human labor that’s necessary to grow food throughout the world, massively influencing the price and quality of the food that we eat.

Other side effects, from dramatic rises in pollution levels to socio-economic effects like mass migration, also contribute to soil degradation’s status as a major global issue.

Sources:

Advances in Soil Science Vol. 11, Soil Degradation

Soil Degradation, Conservation, and Remediation, Khan Towhid Osman

Soil Degradation in the United States: Extent, Severity, and Trends, Rattan Lal, Terry M. Sobiecki, Thomas Iivari, John M. Kimble