Soil erosion, or the movement of soil, is a common problem for many farmers and homeowners. Though simple in definition, the consequences can be dire. Although it is often a natural process, it causes many issues ranging from landscape changes to ecosystem destruction.
While physical landscape changes may be a bother to the amateur gardener, loss of essential nutrients from the soil surface is a harmful effect of erosion. It disrupts the balance of carbon, nitrogen and oxygen in topsoil and agricultural stormwater runoff. This results in dead soil, which lowers the chance of success when planting crops.
The oxygen deficit created through eroding and runoff has created dead zones in the ocean, killing marine life and their habitat. Knowing how to reduce erosion is an important skill in ensuring healthy crops and ecosystems.
What causes soil erosion?
Several farming practices can lead to erosion. When farms are created and native plants are removed, topsoil is left vulnerable. Overgrazing, tillage and heavy fertilization can also lead to crop fields eroding. While farming is a large contributor to the loss of topsoil, agriculture is absolutely necessary to feed our world. We'll always need farmland, so we just need to be responsible and protect our arable land from eroding.
Grade and length of slope are also important factors in noting when and how eroding might occur. Close proximity to non-permeable surfaces such as retaining walls, asphalt and concrete can pose a threat as they do not absorb water and therefore compound the problem. For example, a small concrete wall that is merely 100 square feet will add 100 square feet of water to the slope. The runoff then becomes a compounding problem over time.
Means of soil erosion
When most people think in terms of erosion they are often envisioning creeks and rivers overflowing, torrential downpours and other causes of flooding. While it is true that water is the largest factor, wind plays a very important role.
Open prairies typically have flat areas and lush vegetation. This prevents the strong winds from ripping at the ground and scattering particles everywhere. There is little need for wind breaks due to the prairie grass and flat ground. However, in other parts of the world where the ground consists of rock, silt or clay, wind rapidly chips away at the surfaces and creates a detrimental environment for crops to grow. Imagine a newly established seedling, with roots only ½ inch deep being whipped by the wind. It is likely that the wind would erode the entire base of the soil and expose the root zone, leaving the seedling at risk. The result is barren ground.
Water is the most common eroding factor. Rainy season conditions can destroy pond dams, rip through river basins and tear away crop rows. These natural phenomena are obvious, but the slow unchecked degradation of soil conditions by light rains can be more detrimental if gone unchecked. It's important to be aware of concentrated water flow around farms, as running water with pesticides can negatively impact nearby water quality.
Soil Texture and Conditions
Compacted soil is a real problem. When soil structure evolves to the point where it no longer absorbs water, then erosion is bound to occur. Compacted clay and rocky ground do not hold water. There is also little chance to establish successful crops on compacted soils in order to prevent further erosion.
Likewise, loose and sandy soil is just as problematic. Wind and water are likely to wash and blow sand and soil particles, quickly leaving exposed ground that is not conducive to many natural activities.
Lack of Vegetation
Soils that have little to no vegetation stand to be ripped apart. Nature takes no mercy on barren grounds. That is why weeds, trees and grasses populate so quickly. It is nature's defense against her own elements. It's important to quickly establish cover crops and grass and seed for erosion control on bare ground to protect it from erosion.
Weeds have their place. When forests are timbered and land is cleared, it is a good practice to spread grasses, clovers and allow weeds to temporarily establish. These are situations where irrigation will not be in place, so drought-tolerant plants are better. The focus is not on beauty but strictly on ground cover. This holds in soil nutrients and will reduce soil runoff from the site. Plants hold better than man-made contraptions, such as silt fencing.
Slope and Contour Farming
Being well-versed in slope erosion control will serve you well and give your plants a fighting chance!
Flat surfaces are relatively safe choices when planting seed, but if you are hoping to establish crops on steep slopes, you must be mindful of success rates on different grades. In contour farming, crops are planted in rows level to the slope of the land on which they are planted as opposed to vertically. This can create reservoirs that help conserve rainwater and limit water running off.
Anything steeper than a 25 percent grade will be difficult to establish a healthy root system. Because of this, slope erosion control is especially important. At slopes greater than 25 percent, success rates diminish greatly.
Knowing how to stop erosion on a steep hill is another important skill needed to establish healthy soil. A 3:1 slope ratio means that for every 3 feet of horizontal run, the vertical change is 1 foot. This grade will require special care. On a 2:1 slope ratio, only very large rocks (riprap) should be used to control the erosion.
The slope length is also important in determining crop success. The longer the slope, the greater the gravitational pull of the water when it rains. If you are planting on a long slope, consider building terraces to break up the runoff and decrease erosion.
Loss of soil health is a deadly impact of eroding farmland. When nutrients essential to plant growth are lost, arable land is lost as well and fertile ground becomes and area where no farming can occur. Maintenance of soil health through erosion control can prevent the loss of fertile agricultural land.
Prevention: Farming Techniques That Prevent Erosion
There are many ways to reduce yard, garden or field plot eroding, and most are quite simple. Slowing down the effects of natural elements, such as wind and heavy rain, is important.
Which of the following is the best method for preventing soil erosion in an agricultural area? It really depends on the type of area you're working with and what form of erosion the area faces.
What can be done to prevent soil erosion: Work with Nature, Not Against it
Since wind plays such an important role in the process, you should consider normal wind patterns and seek to establish windbreaks, such as planted trees and structures. Man-made berms can also be positioned in ways to “spoil” the wind up and over areas that need protection.
The easiest and most effective way to prevent erosion is to create root systems through growing cover crops. If you're wondering, what is the most effective method to reduce water erosion on a farm field?, This is your answer. Strong plant root systems hold the soil and create stability beneath the surface. This is a farming method that does not remove the original vegetation from the ground.
Mats, especially on steep grades and inclines, are another farming method used to reduce erosion on steep slopes. As the grade increases, consider the use of rocks or stone riprap to keep soil in place. Another effective prevention method is using contour lines, or planting across a slope instead of vertically on it.
Planting cover crops is a planting technique that helps prevent soil erosion. When establishing cover crops, it is important to be aware of how you are preparing and maintaining the soil. There are many ways to prepare the soil and ensure that your cover crops take root quickly and combat erosion. Striking the right balance of carbon, nitrogen and oxygen will allow necessary microbes to flourish and feed your seed! Using cover crops in crop rotations helps ensure proper micro and macronutrients will be maintained in the soil so it can sustain life for as long as possible.
No-till farming can also help by leaving more crop residue that protects ground from eroding forces. There are many ways to prevent soil erosion, but the most important is a healthy soil environment and root system.
At Southland Organics, we manufacture and sell all-natural soil conditioners that increase seed germination, helping root systems develop faster and stronger. Heartier plants with healthier roots can better withstand erosion!
Which is the best method for preventing soil erosion in an agricultural area? There's really not one that always works in any scenario. It really depends on the area, type of soil and slope. Soil erosion can be best prevented by different methods in different areas.
About the Author
This blog was written by Mike Usry, the President of Southland Organics. Mike is an entrepreneur and soil enthusiast with a passion for educating on agriscience-based topics to help business owners and homeowners alike grow plants, turf, poultry and more. Mike received his Bachelor of Science in Education from the University of Georgia and his MBA from the University of South Florida. The combination of his education and experience has given him a deep understanding of both business and the science behind our products. Mike founded Southland Organics in 2009. Learn more about Mike here.
This blog was edited by Izy Dobbins, Southland Organics' Marketing Manager. Izy has devoted her education and career to communicating science-related topics. With an enthusiasm for sharing accurate and honest content relating to science and agriculture, she ensures Southland Organics' publications are as informative as they are interesting. Izy graduated from the University of Georgia with a bachelor's degree in advertising, minors in both Spanish and environmental health science and a Certificate in Sustainability. She has been working at Southland Organics since 2021. Learn more about Izy here.