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Soil Erosion Problems and Solutions

Soil Education

Soil texture

Dig your hands down into the earth. What do you feel? Every handful of soil has its own individual texture, and those characteristics offer a significant contribution to crops. What determines the unique textures of soil? Why is it important, and which type of soil has more erosion resistance? Find the answers to these questions and more with this informative article.

What Is Soil Texture?

When a pedologist mentions ‘soil texture,’ they’re referring to the amount of various sized sand, clay, and silt particles in a sample of dirt. The composition of these grains makes up the inorganic parts of soil and are the bits and pieces that bind with organic matter to form topsoil.

The size of soil’s particles and their spacing also determines how much water will flow through it. Soil with a higher concentration of large grains of sand will have a greater infiltration rate, while dirt that is primarily clay will pool water on its surface as opposed to absorbing it.

Soil Textural Classes

A soil’s textural classification refers to the combination of sand, silt, and clay that make up the soil. It can be determined using exploratory research methods such as feel. A coarse-textured soil is probably composed primarily of sand, while a fine-textured soil is most commonly dominated by clay.

Farmers can also take a quantitative approach with a hydrometer. With this lab-based method, the soil is mixed with a sodium hexametaphosphate solution to separate the earth’s aggregates into identifiable parts. The U.S. Department of Agriculture outlines 12 primary soil texture classifications including the four most common types: sand, loam, silt, and clay.

Sand

Sand is the largest sized dirt particle. Each grain ranges in size from 2.0 mm down to 0.05 mm. It feels gritty to the touch. Since sand is just a bit of gravel, it drains well but doesn’t do an adequate job of retaining essential water and nutrients. Gravel particles that are larger than 2.0 mm are not considered when determining texture.

Loam

The soil that’s referred to as loam offers a proportion of 40% sand, 40% silt, and 20% clay in a single sample. It’s often the dirt of choice for making bricks and provides plenty of organic material for growing crops.

Silt

Silt particles are considered moderate in size. However, with sizes ranging from 0.05 mm down to 0.002 mm, individual particles are too small to see with the naked eye. It has a similar shape as sand particles, just worn down to a smooth texture.

While it’s not as strong as sand, silt is better at holding both water and nutrients. Because it’s prone to losing small amounts of minerals from each particle, silty soil generally makes more minerals available to your plants.

Clay

The smallest sized dirt particle, clay is less than 0.002 mm in diameter. To put that in perspective, you’ll need to line up 12,000 clay particles side by side to measure one inch. Clay feels sticky in your hands and is an excellent building medium.

What Determines the Texture of the Soil?

The percentage of materials determines a soil’s textural class, including the common particles we’ve already met: sand, silt, loam, and clay. Its texture is an important characteristic that influences a diverse number of properties, including water infiltration rates, aeration, susceptibility to erosion, and pH buffering capacity.

The Importance of Soil Texture

The texture of your field’s soil is essential to a successful harvest on a variety of levels. From saturation to water-holding capacity, let’s discuss each component of soil texture’s importance.

Infiltration

The amount of clay, sand, or silt in the dirt defines the rate at which water is able to drain through it. Once saturated, water moves more quickly through sandy soils than it does through soil that’s heavy in clay.

Availability

Soil texture influences how much water is available to your plants. Once your field’s saturation level reaches capacity, your clay soil will hold more water than its sandy counterpart.

Drainage

Well-drained fields are usually a sign of proper soil aeration. This texture of dirt is rich with air, which promotes a healthy root system and leads to a bumper crop.

Erosion

Different textured soils also respond differently to erosion. Some are more susceptible to loss based on their percentage of silt and clay particles. Those soils have a higher erodibility level than a sandy soil under the same weather and tilling conditions.

Organic Matter

Various soil textures also offer different levels of organic matter. This material breaks down faster in sandy soils than in silt and clay, likely due to the higher availability of oxygen for decomposition.

How Soil Texture Affects Erosion

Now we understand that a soil’s texture is directly related to the amount of clay, silt, and sand particles it contains. But what does this have to do with soil erosion? Soil texture has two main effects on erosion.

First, it influences the rate of infiltration and water’s ability to enter the soil. When it rains, does the water run off rapidly? If so, then you probably have sandy soil. This type of dirt has large pores that act like pipes, channeling water right into the ground.

Does the water collect on the surface or in low lying areas? If it does, then you probably have clay soils that are not known for providing good drainage.

Second, some types of dirt particles don’t detach as easily as others. Silt particles wash away easily because they’re tiny and don’t readily combine with other soil aggregates.

Which Type of Soil Is More Erosion Resistant?

One study suggests that an estimated 30 tons of agricultural soil are lost in the United States to erosion each year. This loss outpaces the rate of formation by an astonishing eight times.

So, which type of soil offers the most erosion resistance? The answer is clay. Clay is better at resisting erosion because it’s small particles hold water, making it a stickier compound than sand.

A soil’s texture affects many aspects of your garden, including erosion. Use this handy guide to help determine your dirt’s composition and how you can use that information to help you conserve topsoil.

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.

How Soil Erosion Can Affect Soil pH

Soil erosion is generally caused by one of two elements: wind or water. These two elements distribute soil sediments differently during erosion. Depending on the conditions surrounding the erosion, there could be economic and environmental losses. Water and wind erosion affect soil content and may reduce microbe induction while raising soil’s acidity, or pH level, which interferes with growth and yield.

Knowing soil’s pH can provide insight into problems such as crop loss and low yield. When a grower knows and understands these issues, they can take action and prevent further economic losses.

What is pH?

A crucial factor for soil health lies in its pH level. pH, or potential hydrogen, measures the concentration of hydrogen ions in soil. These concentrations determine whether soil is acidic or alkaline. pH levels of 5.5 and under are desirable for producing healthy crops. Subsoils should measure 4.8 or lower for more alkaline soil. The lower the pH level, the less acidity is in the soil.

Soil’s acidity or alkalinity determines whether crops will see their full yield, or be reduced unhealthy, acidic crops. pH levels decide the stability of the land for crop production by the measure of nutrients available for both soil and plant health.

While low pH should not result in production losses, high pH concentrations and acidity disturb the induction of microbes into the soil, which will weaken its overall structure.

What is Soil Erosion

Sheet and gully erosion caused by water can strip topsoil of its nutrients and change soil’s structure so that its underlying subsoils are also compromised. Saltation, an effect of wind erosion, tosses soil particles into the air and carries them great distances. These particles can cause upper respiratory conditions to flare while they blanket homes and roadways, and smother crops.

The environmental impacts of soil erosion are felt in loss of crop yields due to soil compromise and nutrient unavailability. Loss of animal habitat is felt as insects and microbes are partly responsible for soil’s structure and integrity.

Agriculture suffers overall as it is this land stripped bare of its vegetation. It is bare land that is most vulnerable to erosion and resulting acidity. Development also suffers losses as infrastructure is weakened by erosion.

How Does Soil Erosion Affect Soil pH?

Soil that is maximized to maintain its value as a resource to produce healthy, thriving crops is lower in pH for alkaline soil. Reducing high acidity in soil is needed to produce strong crops and prepare the land for the next growing season. 

As erosion occurs, it takes more than just soil. Erosion carries fertilizers and pesticides along with it as it flows or blows. These sediment deposits might affect surrounding soils and spread (or cause) acidity to nearby areas. Because acidic soil is responsible for nutrient deficiencies and toxicities found in plants, balancing pH is a crucial component to economic health.

As erosion contributes to a rise in the water table, and because pH is usually higher in moist soils, water erosion poses serious consequences to soil’s balance and stability. As acidity accumulates, it might affect surrounding areas by furthering the imbalance and making it that much more difficult to correct or offset the damage.

Managing Acidic Soils

Once pH levels are high in topsoils, underlying subsoil horizons might also be affected. If the parent layer, or O horizon, becomes too acidic, the fight to bring back balance intensifies. Knowing the pH levels of planting ground before the first crops go in is a wise move to prevent unexpected disaster.

Fortunately, there are methods a grower can use to reduce soil acidity and bring pH levels to their ideal levels for their incoming crops.

  • Applying the proper amount of nitrogen and sulfur fertilizers can have a positive effect on pH and lower its levels over time. The key is adding the proper amounts of fertilizer at the appropriate time depending on the crop’s needs.
  • Liming is a tried-and-true method of lowering soil pH. However, this method has proven to be time-consuming and labor-intensive. Moreover, not every farm can afford to purchase lime to control pH. Liming’s effects tend to last a short time and may contribute to nutrient deficiencies in the soil. Liming may also trigger a decline in microbes, compromising soil’s crucial make-up.
  • Cropping practices that improve soil’s organic matter and soil’s overall health is the ideal method of reducing soil pH. Geotextiles in natural fibers like coir can be used in strip planting and terracing to serve double duty: reduce effects of erosion and balance soil pH. Coir’s neutral pH makes it an ideal accompaniment for soil to maintain its overall structure and integrity.

How to Test Soil pH

Testing soil pH is relatively simple and can be performed with various measurement techniques. Be sure to test soil in more than one location for an accurate pH range.

  • PH kit with pH paper: Look for kits that contain a relatively broad pH level scale of 1-14. Some kits may concentrate the range with reading levels between 4.5-10. This method tests soil by adding in a little water then dipping the strip in the soil to take a pH reading. 
  • Soil pH meter: These meters are used by pushing the probe into the soil to read the meter’s measurement. 

How to Prevent pH Imbalances in the Soil

Reducing runoff and erosion are key components in maintaining soil’s ideal pH. Protecting bare land with added vegetation and the use of geotextiles is warranted and recommended to reduce the effects of soil nutrient loss. Additionally, frequent soil testing can alert growers to potential problems before they plant the first seeds.

Soil is composed of many elements for a reason. A living, evolving material, soil’s make-up can be compromised by excessive erosion or runoff that not only affects the growing topsoil but the supporting horizons beneath. Soil pH doesn’t have to be complicated to maintain, and with a little diligence and regular testing, soil will sound the alarm when there may be something wrong.

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.

Everything You Need to Know About Soil Maps

Soil maps are an essential tool when it comes to land management. As knowledge about the environment grows, experts are learning that what is done in one area can have farther reaching impacts on the surrounding area. Mapping sustainable and unsustainable land for the long term is an excellent way to ensure proper planning, and the best way to move forward. Think of soil maps as a much larger version of testing the soil in your garden. Let’s deep dive into this topic and see how it can help your gardening efforts.

At the beginning of your growing season, most farmers and gardeners make the decision to test their soil. It’s important to determine whether or not you need to add fertilizer to your garden to provide your plants with the elements they need to grow strong and healthy. You don’t want to plant your garden with too much or not enough of a particular nutrient in the ground. In the long run, this practice could cause problems with your plants not performing as expected. 

What Are Soil Maps?

Think about how your backyard garden is set up. You may have several different types of soil to work with around the yard. For instance, you may not use the back portion because it has heavier clay soil, while the middle of your backyard has better soil for your garden’s vegetable plants. This soil is more conducive to successful gardening without requiring any changes, unlike the clay areas. On a smaller scale, when you test your garden soil, you’re creating your own soil map. 

The United States Department of Agriculture’s Natural Resources Conservation Service collects data and creates soil maps. They collect web soil survey data from throughout the country that examines the soil in detail. They then compile the web soil survey data into the soil maps. The maps will describe and classify the type of soil found in these areas. Soil-type maps can then help determine land management practices based on what dirt is located in that particular area.

How Are Soil Maps Made?

The USDA creates soil maps through a variety of means. They go out to the region they are mapping and compile data through physical field sampling and technology. They collect additional data through aerial photography and other sensing technology.

Technology has changed how the USDA maps the regions where they gather data. In the past, researchers had to use paper maps, cameras with film that needed to be developed, and topographic sheets to input their data. 

Now, they can use tablets that offer GPS and all of the map equipment they need on it. Their digital photos and other data can all be combined using the tablet, to create the soil map as they go along. An additional technological benefit is that in the past these surveys had to be printed. It could take years for the public to have access, which left the potential for the public to only have access to outdated information. That’s no longer the case with the use of tablets, computers, and online publishing. 

Information Included in the USDA Soil Survey

A USDA soil survey includes a wide variety of information that provides all of the data. It starts with an overview of the geography of the area, data about the major soil types, detailed pictures, and information on crops and plants located in the area. It also includes in-depth information on the soil, such as depth of the dirt, texture, and permeability.

Value of USDA Soil Survey Maps

To many, dirt is just dirt. The soil is so much more than that, though, as the qualities of the earth can differ from place to place. Land can have limitations and benefits that prompted experts to create a classification system for clay that’s called soil taxonomy. This taxonomy establishes a basis for the proper agricultural and engineering applications available for the soil that exists in a particular spot. 

Who Uses Soil Maps?

It may seem like soil maps aren’t something accessible for anyone outside of the US government but these maps are beneficial to other groups. Anyone can get access to the soil maps the USDA creates. The plans are available to the public and have a variety of uses. People can visit the Web Soil Survey site or WSS to access the data and create their own custom soil survey of the areas they choose.

What are Soil Maps Used For?

Developers and builders can use these maps to help in planning out their buildings. The structure of the soil can be crucial to whether or not the area can support development. The ground may be more beneficial for a particular type of construction, or it may show that building in that site isn’t advisable. 

Businesses that work with soil, such as farms and ranches, can use soil maps to determine where they should plant their fields or graze their livestock. They can use the information from the soil survey to determine if they should move their flocks to another area or if they should leave a particular field fallow. It can also help if they plan on expanding their farms with an additional property, to give them an idea of whether or not the soil in the area can support their plans.  

Even homeowners can benefit from using soil maps. The maps can help them when it comes to starting a garden, planting trees, picking out a new home, or even adding on to an existing home. The information can allow you to make an educated decision on matters that pertain to the land around you.

Whether it’s a prominent developer building a new shopping plaza or a homeowner trying to determine the best place in their backyard to grow vegetables, soil mapping is beneficial. The soil that’s under every building, park, farm, and place on earth has a story to tell. Soil maps make it possible to make the right decision for future soil planning on every level.