Nitrogen management and nitrification inhibitor effects on nitrogen-15 urea. II. Nitrogen leaching and balance

Nitrification inhibitors (NI) may reduce N leaching losses, and should have the greatest effect on sandy soils where leaching potential is high. This study used 27 lysimeters to evaluate the effect of a NI, nitrapyrin [2-chloro-6(trichloromethyl) pyridine], on soil water percolation (SWP) and N leaching losses from an irrigated sandy loam soil (Typic Hapludoll) planted with corn (Zea mays L.), and monitor the fate of a single application of ¹⁵N-enriched urea over a multiyear period. Nitrification inhibitors may reduce the potential for nonpoint-source pollution by delaying NO₃ leaching, but will be most effective if coupled with proper N rates and conservative irrigation water management.