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K-State Research and Extension

Cover crops and fertilizer management improve water quality

What we are doing:

cover cropsScientists test water runoff from corn and soybean fields at the Kansas Agricultural Watershed Laboratory south of Manhattan. The 22 acres of cropland are divided into 18 plots, each about the size of a football field. Researchers track the runoff of sediment, phosphorus and nitrogen as it snakes its way to local streams and rivers. Poor water quality affects nearby land values. When cities pay more to clean drinking water, it ultimately means a bump in water bills for homeowners.

Our impact:

A research team led by agronomist Nathan Nelson is using winter cover crops, such as triticale, rapeseed or winter wheat, and 4R nutrient management (Right source, Right rate, Right time, Right place) to protect and enrich the soil, reduce phosphorus loss and improve water quality. The team found that planting cover crops can reduce soil loss, or erosion, by 70 percent compared to land where cover crops are not planted. Subsurface placement of phosphorus fertilizer can reduce phosphorus loss by more than 25 percent. Reducing soil and phosphorus loss helps protect public waterways and improve long-term productivity of Kansas farm ground.

“Dr. Nelson’s timely research with cover crops in combination with fertilizer best management practices is providing farmers with quantifiable results and clarity on ways to improve water quality without sacrificing productivity. Not only do farmers benefit from this research but also all the communities in the watershed clear to the Gulf of Mexico.”

— Justin Knopf, Gypsum farmer and Kansas Association of Wheat Growers vice president