Location: Iowa State University
Featuring: Derek, Research Soil Scientist
The drainage water in agricultural fields significantly contributes to nitrate contamination of Iowa surface waters and the Mississippi River.
In fields where the water table is close to the surface, tile drainage is used to remove excess water from the soil. This contributes significantly to nitrate (N) contamination of Iowa surface waters and ultimately the Mississippi River.
At Iowa State University, scientists use sump pits to collect water samples from three fields using different farming practices. Then they calculates the concentration and volume of nitrate in this subsurface drainage water. Nitrate testing in these fields shows that organic farming leaches less nitrogen than more conventional methods.