Mitigation of ammonia volatilization and nitrate leaching via loss control urea triggered H-bond forces

Abstract

Excess nitrogen (N) fertilizer applied to crops, which discharges to the environment, principally through denitrification, runoff, leaching, and volatilization, results in a waste of resources and pollution. Here, a high-performance loss control urea (LCU) was prepared by adding a loss control agent (LCA) with high thermal stability, large specific surface area, and good water retention capacity complex (6%) to traditional urea (94%). The existence of hydrogen bonds between LCA and N source for LCU in the presence of water enhanced N source adsorption capacity, where adsorption between LCA and NH4+-N was strongest, for urea and NO3−-N was weakest. In a laboratory experiment, cumulative losses of NH3 volatilization from soils treated with N application rates of 80, 160 and 240 kg N ha−1 were 14.8, 18.1, and 24.2% for urea, respectively, and 10.1, 12.7, and 17.5% for LCU. Simulated rapid and long-term leaching experiments showed that, compared with urea, LCU reduced N leaching loss within 30 d, and delayed long-term N leaching loss. Hydrogen bonds in LCU effectively controlled NH3 volatilization and N leaching loss. This type of LCU may optimize supply of N in soils and increase adsorption and utilization of N in crops.