By Naeem Kalwar
Losing six inches of topsoil could cost farmers more than $6,600 in nutrients and organic matter, according to a new analysis by North Dakota State University researchers.
Topsoil is the most fertile layer of a soil, rich in microbial activity and essential for crop production. When it erodes, thousands of dollars’ worth of nutrients and organic matter erode with it.
NDSU researchers’ findings showed that the cost of direct nutrient loss and nutrient loss due to organic matter loss totals over $1,100 for every inch of lost topsoil, or $6,600 for a 6-inch layer.
These numbers show that soil erosion is an economic issue, not just an environmental one, says Naeem Kalwar, NDSU soil health specialist at the Langdon Research Extension Center. “Protecting topsoil from erosion is crucial. That layer is where farmers plant seed, and it is responsible for feeding the world.”
Soil erosion, which is the loss of soil sediments or material, can happen due to wind, water and tillage. Tillage can worsen wind- and water-related erosion by loosening the soil. When topsoil erodes into roadside ditches, it pollutes the drinking water for humans and livestock.
“Farmers, ranchers and landowners will eventually have to pay to replace those nutrients,” says Kalwar.
Kalwar set out to determine the value of an inch of topsoil in terms of replacing lost crop nutrients and organic matter. Researchers collected a 6-inch-deep sample of topsoil that had eroded into a roadside ditch from an adjoining field and sent it to a soil testing laboratory for a comprehensive fertility analysis. Results showed appreciable quantities of essential plant nutrients and a significant amount of soil organic matter.
Source : ndsu.edu