NO3-N Concentrations in Shallow and Deep Groundwater Wells from 1991 to 2003

Nitrates from fertilizers and manure application have been detected in the surface and groundwater in many agricultural regions of the country including Iowa. The current practices of fertilizer application methods and rates are believed to be contributing significantly in the contamination of groundwater. Therefore, it is imperative that tillage and planting systems, regarded as best management practices for agricultural sustainability, minimize the potential for chemical runoff and leaching losses into groundwater with alternative chemical management systems. If the potential for contamination is not reduced by developing and successfully demonstrating the innovative nitrogen management practices, additional regulations could be the result.