The Continuing Challenge of Agricultural Nitrogen Loss to the Environment in the Context of Global Change and Advancing Research

Abstract

Excess nitrogen in soil, aquatic and atmospheric environments is an escalating global problem as a result of technology and human actions increasingly dominating the nitrogen cycle at all environmental scales, which often leads to an accumulation of reactive nitrogen compounds in ecosystems. While sources of environmental nitrogen pollution are diverse and agriculture is not solely responsible, there is growing concern about the large number of identified impacts on water quality and greenhouse gas emissions, which originate from intensified agricultural management with its continually increasing nitrogen fertiliser consumption. Interactions of nitrogen in and with the environment are complex and our understanding of nitrogen cycling continues to be re-defined with the discovery of new nitrogen cycling processes and pathways. There is an increasingly urgent need for interdisciplinary, international studies that holistically investigate measures to control nitrogen losses and reduce agricultural costs while maintaining productivity. This is best achieved by joint actions among researchers, land managers and policy makers by assessing and implementing improved farm management practices that optimise agricultural production, minimise adverse effects on human and animal health and reduce environmental pollution. Similarly promising approaches to enhance environmental and economic sustainability of agricultural production are put forward by recent studies that take advantage of the improved understanding of soil nitrogen processes and plant uptake.