Reactive Nitrogen inflows and Nitrogen use efficiency in agriculture: An environment perspective

Abstract

Increased use of nitrogenous (N) fertilizer has significantly altered the global N-cycle and produced nitrogenous gases of environmental consequence. While nitrous oxide (N2O) emissions contribute to global greenhouse gas accumulation and the stratospheric ozone depletion, degradation of groundwater quality by N use in agriculture is fundamentally a nitrate leaching problem. Despite these evident negative environmental impacts, consumption of N fertilizer cannot be reduced in view of the food security for teeming population in the developing countries. Various strategies, from agronomic to genetic engineering, have been tried to tackle this problem. Split application of N, use of slow-release fertilizers, nitrification inhibitors, and the use of organic manures are some agronomic techniques adopted. One of the important goals to reduce N-fertilizer application can be effectively achieved by choosing N-efficient (i.e., which can grow under low N conditions), ensuring their optimum uptake of applied N by application of adequate amounts of fertilizer nutrients in a balanced manner and knowing the molecular mechanisms for their uptake as well as assimilatory pathways. Newer approaches like quantitative trait locus and proteomics could also help us in understanding these processes fully, hence could contribute greatly in enhancing nitrogen use efficiency and reduction of N pollution in the environment.