This week, NPR followed up on a story about nitrates in Iowa’s water supply.
During the initial broadcast, journalist Dan Charles mentioned fertilizer as a source of nitrogen on the farm crops. The nitrogen in the fertilizer turns to nitrate, which runs off and into streams.
Sara Carlson of Practical Farmers of Iowa contacted Charles and explained nitrate is usually used by plants in the soil, but when the soil is barren — like soybean and corn fields are in the winter — the nitrate continues to be produced with nowhere to go.
The solution? Cover crops.
What Is A Cover Crop?
A cover crop grows during the winter when everything else freezes.
In Indiana, that means rye or wheat, or certain late summer or early fall legumes, like hairy vetch, bigflower vetch, Austrian winter peas and crimson clover.
Not only do cover crops keep nitrate from overflowing into streams and then wreaking havoc on habitats and wildlife, they protect against water and wind erosion, improve the soil, and boost crop yield.
Cover crops also attract honeybees and beneficial insects.