Challenges and opportunities for mitigating nitrous oxide emissions from fertilized cropping systems

Abstract

Nitrous oxide (N2O) is often the largest single component of the greenhouse‐gas budget of individual cropping systems, as well as for the US agricultural sector as a whole. Here, we highlight the factors that make mitigating N2O emissions from fertilized agroecosystems such a difficult challenge, and discuss how these factors limit the effectiveness of existing practices and therefore require new technologies and fresh ideas. Modification of the rate, source, placement, and/or timing of nitrogen fertilizer application has in some cases been an effective way to reduce N2O emissions. However, the efficacy of existing approaches to reducing N2O emissions while maintaining crop yields across locations and growing seasons is uncertain because of the interaction of multiple factors that regulate several different N2O‐producing processes in soil. Although these processes have been well studied, our understanding of key aspects and our ability to manage them to mitigate N2O emissions remain limited.

Global metaanalysis of the nonlinear response of soil nitrous oxide (N 2 O) emissions to fertilizer nitrogen

“…Needed especially are additional studies in climate zones other than north temperate, in rice and upland grain crops, and with different fertilizer formulations and application timings. Further knowledge of the factors and practices that affect N 2 O emissions from agricultural soils is crucial not only for developing effective mitigation strategies for this important GHG but also for developing a more robust means for balancing the global N 2 O budget (18,23,35).…”

Enhanced-Efficiency Fertilizers in Nitrous Oxide Emissions from Urea Applied to Sugarcane

“…Cantarella (2007), Ghiberto et al (2009), andGhiberto et al (2011) observed very little NO 3 -leaching from N fertilizers in sugarcane using fertilizers labeled with 15 N. Although losses of N as N 2 O are environmentally important, they are a small fraction of fertilizer costs, and sugarcane growers may not be willing to pay the cost of NIs if no yield increases accompany this environmental benefit. Mitigating N 2 O emissions from agriculture may, therefore, require broader approaches, such as the internationalization of costs of GHG abatement Venterea et al, 2012), in addition to the technical solutions found by researchers.…”

Evaluation of the Agronomic Impacts on Yield-Scaled N2O Emission from Wheat and Maize Fields in China

“…Additionally, more work is needed to optimize the application options of inorganic N fertilizer (such as N source, placement and application time) that allow for N-rate reductions to better match crop growth demand and mitigate N 2 O emissions without yield loss in high-yield croplands [41]. Improving these options could lessen the need for financial compensation [42].…”