The Iowa Environmental Protection Commission is considering banning the practice of spreading manure on farmland that’s been planted with soybeans. DNR Division Administrator Wayne Gieselman says the proposed ban makes sense because soybeans don’t need the nitrogen the manure provides.
Gieselman says soybeans are legumes, a plant that can “fix” nitrogen they absorb out of the air and don’t need supplemental sources of nitrogen applied to their soil, which sets it apart from corn. At its meeting this week, the E-P-C directed the Department of Natural Resources to write a rule outlining the ban so they can consider it at their November meeting.
The purpose of the rule is intended to cut down on the amount of nitrates entering Iowa waterways by means like drainage through field tile or leaching through the sub-surface. Gieselman says there’s no sense in applying manure to ground that’s going to be used for a crop that does not need the nitrogen that’s available in manure. “To a certain extent, spreading manure on soybean ground is essentially wasting the nutrient value,” Gieselman says. He adds it’s probably not happening to any great extent, but shouldn’t be happening at all.