Does Healthier Soil Produce Significant Nitrogen?

By Jonathan Eisenthal

Farmers who engage in soil health practices like no-till and cover crops—especially those who have engaged in these practices for ten years or more—often describe a reduced requirement for nitrogen fertilizers. 

But this phenomenon has not been tested and quantified, according to soil scientist Anna Cates, who is close to completing the first year of a three-year project that closely examines the relationship of those practices to measures of biological activity in the soil, and then attempts to draw the connection with changes in the Economic Optimum Nitrogen Rate for fields where soil health practices are used. Cates is a professor at the University of Minnesota, and the director of the Minnesota Office of Soil Health (MOSH). 

Cates’ project, funded by the Minnesota Corn Checkoff, uses ‘triplets’ as the basis for comparison. 

“Triplets are three fields, in close proximity, each with different management. That way we can control for soil and weather during the growing season’s effects on corn yield. Precipitation (in Minnesota) can be especially localized, so it’s nice to have things close.”