This practice involves moving all current fall anhydrous ammonia and/or fall liquid swine manure application to the spring before planting.
An estimated 12.9 million acres out of 50.6 million acres in the Midwest Corn Belt have fertilizer nitrogen applied in the fall. If this fractional estimate is applied to Iowa, approximately 3.12 million acres have fertilizer applied in the fall. The research summary showed there could be an average 6% reduction in nitrate-N concentration in tile drainage water when moving from fall to spring-applied nitrogen fertilizer, considering the same application rate. (It's important to note that 6% reduction on areas where this practice could be implemented would translate into only a 1% reduction in nitrate-N loss statewide.)