Challenge #1: Soil Erosion from Agricultural Fields
Land degradation due to soil erosion
Soil erosion adversely impacts agronomic productivity. Additionally, soil erosion negatively impacts the environment, food security, and quality of life. The effects of soil erosion have both on-site and off-site impacts. For example, on-site impacts may include reduced crop yield and increased nutrient loss, while off-site impacts may include water contamination and increased food prices.
Three reasons why soil erosion is an important issue:
- Soil erosion impacts soil quality and productivity
- Soil erosion impacts the quality of the environment
- Because of 1 and 2, soil erosion impacts world food production
Further evidence of the impact of soil erosion is supported by Eswaran et al. (2001): “The productivity of some land has declined by 50% due to soil erosion and desertification.”
Harris and Iyer (2014) also capture the severity of soil erosion by saying:
“…over half of the prairie-built topsoil of Iowa has been lost in the past 50 years.”
Pictured below is an example of gully erosion caused by water carrying soil particles down slope along a grass strip. Gully erosion is one of the most noticeable types of erosion. Sheet erosion is just as severe, yet less noticeable.
(photo by Willard Mott, 2017)
Soil erosion reduces soil quality (Brady and Weil, 2008).
The following are potential negative consequences of soil erosion:
- Loss of organic matter
- Loss of soil structure
- Reduced nutrient cycling
- Reduced soil depth
- Reduced water holding capacity
- Change in soil pH
- Changes in soil texture (percent sand, silt,clay)
Soil Erosion Rates
Although soil erosion rates have decreased over the past 25 years, 28% of all cropland is still eroding above soil loss tolerance levels. The national average soil loss in 2007 was 4.8 tons per acre per year compared to 7.3 tons per acre per year in 1982 (NRCS, 2017h).
Figure 1. Erosion Rates on Cropland, 1982-2007 (NRCS, 2017h)
Soil erosion is one challenge of agricultural production. For more information on the potential consequences of soil erosion and the various types of soil erosion, please click the following link to read the article:
“Soil erosion: An agricultural production challenge”
by Mahdi Al-Kaisi, Department of Agronomy, Iowa State University.