STATE COLLEGE, Pa., June 14 (UPI) — A U.S. ecologist says she’s found straw residue left in fields after grain harvesting reduces nitrogen leaching into waterways, but might also reduce profits.
Anna Starovoytov of Pennsylvania State University’s College of Agricultural Sciences says agriculture is the largest source of nitrogen pollution in U.S. waterways via erosion or leaching from the soil. Minimizing nitrogen pollution is a key environmental goal since it not only degrades the ecosystem, but nitrates in drinking water are linked to various cancers and birth defects.
“In this study, three different quantities of straw residue were spread on research plots that were later planted with hairy vetch,” Starovoytov said. “A corn grain crop was later no-till planted into the vetch/straw residues. The type of residue present affected not only the magnitude of the peak of nitrogen in soil, but also the timing of this peak, which is important when considering the synchrony of nitrogen availability to corn nitrogen demand.”
Her study, led by Associate Professor Robert Gallagher, revealed that adding straw residues to hairy vetch cover crops tended to lower soil inorganic nitrogen content but also negatively affected corn yields by as much as 16 percent.
The study that included Assistant Professor Jason Kaye and researchers Brosi Bradley and Krista Jacobsen appears in the May/June issue of the Agronomy Journal.
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