Erosion of Topsoil Across the Midwest

Midwestern Regions of the United States are some of the most productive agricultural landscapes. Their carbon-rich soil is an essential contributor to the agriculture of crops and is considered the foundation of its productivity (Thaler, Larsen, & Yu, 2021). Unsustainable farming practices have caused topsoil to be overturned and left vulnerable to erosion by winds and water. Surveys were completed by researchers at the University of Massachusetts Amherst. They measured the eroded soil, comparing them to the natural prairie remnants. Results show that topsoil has declined by a rate of 2 mm per year over the past 150 years (Thaler, Kwang, Quirk, Quarrier, & Larsen, 2022). If the erosion of topsoil continues at this rate, successful agriculture in the United States may no longer be possible.

The Corn belt encompasses twelve midwestern states that have dominated United States agricultural production. This agricultural region produces important crops such as corn and soy which are vital to supporting the ever-growing global population. The landscape in these areas mainly consists of tallgrass prairie or savanna. The soils in this area are classified as carbon-rich mollisols (Thaler, Kwang, Quirk, Quarrier, & Larsen, 2022). Certain prairies in Midwest regions remain unaltered and provide locations that have preserved the presettlement topography (Thaler, Kwang, Quirk, Quarrier, & Larsen, 2022). This is essential for researchers when comparing the erosion of agricultural soils and natural prairie landscapes. Large amounts of this productive soil have been eroded leading to topsoil degradation and damage to environmental services.

Topsoil is actively eroded by many natural factors such as strong winds, rain, and flowing water. However, there are also high rates of erosion caused by certain farming methods (Thaler, Kwang, Quirk, Quarrier, & Larsen, 2022). When farmers overturn the soil through the process of tilling they are loosening the soil and overturning the ground. This leaves the soil vulnerable to erosion by natural winds and water. This can cause negative effects on the remaining soil, such as a decrease in soil thickness. When the soil is eroded, further negative offsets such as sedimentation and the movement of nutrients occur. It also can reduce remaining soil nutrients, making it difficult for the soil to support plant growth and water storage (Gamillo, 2022).

Researchers at the University of Massachusetts studied the differences in natural prairie remnant topography and the tilled agricultural landscapes. This study was conducted across several states in the Midwest including Iowa, Illinois, South Dakota, Minnesota, Kansas, and Nebraska (Gamillo, 2022). The prarie remnants that were examined are able to show the landscapes of this area pre-European settlement when they began being used for large-scale farming. This significantly lowered those certain areas due to their vulnerability to erosion. The results of this study showed that on average the farmed regions were 1.2 feet below the prairie landscapes (Gamillo,2022).

Since soil is being degraded, it makes it more expensive and difficult to grow crops. At the rate the population is increasing, this issue needs to be made a priority. Without an abundance of nutrient-rich soil, nutrient-rich food cannot be grown to appease this increasing demand. This leads to an increase in the cost of goods, making fresh food less accessible and affordable. Erosion of topsoil diminishes soil fertility as this process removes nutrients and organic matter (Thaler, Kwang, Quirk, Quarrier, & Larsen, 2022). This can also lead to reductions in crop yields and further contribute to rising prices and food shortages.

To prevent the future impacts of this unsustainable erosion, farmers can implement no-till practices such as using disc seeders or agricultural drills. Along with this, soil regenerative practices may be necessary to reduce erosion rates (Thaler, Kwang, Quirk, Quarrier, & Larsen, 2022). Many of these practices are already common and are currently used by 51 percent of soybean, cotton, corn, and wheat farmers in the United States (Gamillo, 2022). Despite this, there are political, social, and economic barriers to this issue (Thaler, Kwang, Quirk, Quarrier, & Larsen, 2022). Providing incentives around no-till farming is essential for reducing soil erosion. No-till farming is necessary for soil productivity, ecosystem services, and long-term sustainability (Thaler, Kwang, Quirk, Quarrier, & Larsen, 2022).