Other factors are the length and slope of a piece of land, which can affect the speed and strength of water runoff. Vegetation—typical cropping as well as the strategic use of cover crops—can buffer the impact water has on a farm field.
Land managers may also mitigate soil erosion through selective tillage practices. Typically, farmers till their soils to prepare fields for seed planting, control weeds, and retain moisture. But decades of agricultural research has revealed that a less-is-more approach may be the best way to minimize soil erosion. In other words, reducing mechanical disturbance to farm fields may help preserve soil.
Water, though vital for life and agriculture, can be incredibly corrosive. Every raindrop splash has the potential to impact the structure of soil. Below are four common types of water erosion. Sheet erosion —the removal of soil in thin, uniform layers sheets by raindrop impact and shallow surface water flow. Sheet erosion can sometimes be difficult to detect unless the soil is deposited nearby or if the damage is already severe.
This erosion process removes the fine soil particles that contain most of the important nutrients and organic matter. Rill erosion —a type of erosion that results in small yet well-defined channels—typically smaller than gully erosion channels. After some time, rill erosion may fade away or, in more serious cases, be smoothed over with tilling.
Gully erosion —the washing away of soil through deep grooves or channels across unprotected land. Gully erosion can refer to soil being washed away through human-made drainage lines or describe the process of soil traveling through grooves created by hard rains.
Farmers will typically fill these grooves back in with fresh soil as a temporary solution. As seen across the Midwest in , gully erosion can hinder the ability to plow fields and grow crops. Bank erosion —the progressive undercutting, scouring, and slumping of natural rivers and streams as well as man-made drainage channels by the intense movement of water. When land managers remove vegetation or ranchers allow their livestock to overgraze the land near streams and riverbanks, it can exacerbate the problem.
Bank erosion represents a serious threat to lands around the globe. For example, the claylike soil of southwestern Bangladesh is particularly vulnerable to erosion during the rainy season. Every year, riverbank erosion displaces tens of thousands of people and has a devastating impact on regional farming.
The effect of soil loss depends on the type and depth of the topsoil that has been washed away. As topsoil is lost, the ability of the remaining soil to hold nutrients and moisture is diminished—which can greatly reduce crop emergence, growth, and yield. Some seriously eroded soils are not usable for crop production at all. If areas remain flooded during the planting season, it can delay or impede the planting of new crops. Water erosion can also have dire consequences beyond farm fields: The devastating series of floods that caused destruction in much of the Midwest in sent record volumes of agricultural runoff into waterways.
The impacts of excess fertilizer can be disastrous for aquatic systems as well as public health. Each summer, high levels of manure and fertilizer are responsible for harmful algal blooms that not only kill marine life by depleting oxygen in the water but leave fresh water undrinkable and unsafe for recreation.
Wind erosion is a natural process that moves loose soil from one location to another. Very strong winds, in fact, can form large, destructive dust storms. In drier regions of North America, millions of tons of soil are lost to wind erosion annually. In October , a huge dust storm , visible from space, moved across the Great Plains , from Colorado into Nebraska and Kansas.
One study found that dust storms have become more common and more intense over the past 20 years due to frequent droughts and the expansion of croplands. Soils types that are loose, dry, and finely granulated are less desirable for farmland, as these qualities create smooth surfaces and increase erodibility. On the other hand, soil structure—roughness, clumps, and ridges—can help absorb wind energy and reduce erosion.
Fields that are covered with vegetation or bordered by shrubs and trees also known as shelterbelts are also much less vulnerable, as the plants can help block wind. Last but not least, climate plays a big role in wind erosion: Studies suggest that a warmer climate would bring a greater risk of wind erosion on arid and semiarid lands. Like water erosion, wind erosion can harm the fields where it picks up soil, as well as the areas where the dirt—and whatever minerals and contaminants it includes—are deposited.
It can also have health impacts: worsening air quality, obscuring visibility, and causing people to experience breathing difficulties. Below are some examples of the effects of wind erosion on farmland. In this way, we can help prevent hunger and mitigate the climate crisis.
To learn more about WRI's work restoring eroded soils, click here. WRI relies on the generosity of donors like you to turn research into action.
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Search WRI. More on. Forests land use restoration agriculture food security. What Are the Impacts of Soil Erosion? Use Soil-friendly Agricultural Practices Terraced farming needs to be implemented to make hillside agriculture manageable.
Offer Incentives for Land Management Although the science of sustainable land management has been gaining support, the socio-economic context often makes implementation difficult. Prevention AND Rehabilitation The key to managing and reducing soil erosion is to rehabilitate already-damaged land , stop further degradation and put erosion-preventative measures at the core of land management policy.
Relevant Work Forest and Landscape Restoration. Forest and Landscape Restoration. The Road to Restoration Research October 1, Tractor tires make deep grooves, which are natural pathways for water.
Fine soil is blown away by wind. The soil that is most likely to erode is the nutrient-rich topsoil, which degrades the farmland. Figure 1. Grazing animals Figure 2 wander over large areas of pasture or natural grasslands eating grasses and shrubs.
Grazers expose soil by removing the plant cover for an area. They also churn up the ground with their hooves. A land is overgrazed if too many animals are living there. Grazing animals can cause erosion if they are allowed to overgraze and remove too much or all of the vegetation in a pasture. Logging removes trees that protect the ground from soil erosion. The tree roots hold the soil together and the tree canopy protects the soil from hard falling rain.
Logging results in the loss of leaf litter , or dead leaves, bark, and branches on the forest floor. Leaf litter plays an important role in protecting forest soils from erosion Figure 3.
Many of the tropical forests that remain are currently the site of logging because North America and Europe have already harvested many of their trees Figure 4. Soils eroded from logged forests clog rivers and lakes, fill estuaries, and bury coral reefs. Figure 4. Deforested swatches in Brazil show up as gray amid the bright red tropical rainforest.
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