In field Management

Nitrogen fertilizer use is not the primary reason for nitrate loss, nevertheless improved nitrogen fertilizer management is important and can contribute to reducing loss.

  • Most nitrate loss to Iowa waterways is caused by a mismatch in timing between nitrate production from soil organic matter and nitrate demand from rapidly growing drops. The majority of nitrate is lost when there is little crop growth (in April- June). 
  • Nitrate loss from corn and soybean crops is the same despite the fact that fertilizer is applied to corn and not applied to soybean.