Move over, Farmville. Researchers at the University of Missouri have simulated a century of agriculture. A graduate student at MU in Columbia, Mo., used computers to help him step back in time and watch how soil changed as prairies turned into farms.
Much of America’s grassland was plowed under to make way for corn, soybeans and other crops before accurate records were kept. Farmers, conservationists and scientists want to know how soil changed under cultivation. Knowing that allows them to understand the value of prairies and develop strategies to protect or restore the land’s fertility.
Ashish Mudgal, who recently received his doctorate from MU, observed dramatic changes in soil fertility and pesticide runoff. During the 100 years of simulated agriculture, corn yields declined by 39 percent and soybean yields fell by 75 percent.
Pollution washing off from the land also increased. The average annual amount of the herbicide atrazine in runoff went up by 82 percent.
Some research has associated atrazine with deformities in wildlife, but the Environmental Protection Agency has deemed it safe. Atrazine is banned in the European Union because of possible groundwater contamination.
To model a century of agriculture, Mudgal measured the characteristics of soil from a never-farmed prairie and from a field cultivated for 100 years. He fed those measurement into a computer model developed at Texas A&M, called the Agricultural Policy Environment Extender. The computer program estimated changes in erosion, runoff and the flow of sediment, nutrients and herbicides.
“These results show that the restoration of agricultural lands would be beneficial not only to enhance crop yields but also to reduce nonpoint-source pollution,” Mudgal said in an MU press release.
The research helps put economic value on restoring prairies, since they are associated with higher soil quality. Simulations like this could help develop land management strategies that used the natural fertility of prairies in rotation with farming to reduce fertilizer dependence and pollution while increasing grain production.