Nitrogen fertilizer management for nitrous oxide (N 2O) mitigation in intensive corn (Maize) production: An emissions reduction protocol for US Midwest agriculture

Abstract

Nitrous oxide (N 2O) is a major greenhouse gas (GHG) product of intensive agriculture. Fertilizer nitrogen (N) rate is the best single predictor of N 2O emissions in rowcrop agriculture in the US Midwest. We use this relationship to propose a transparent, scientifically robust protocol that can be utilized by developers of agricultural offset projects for generating fungible GHG emission reduction credits for the emerging US carbon cap and trade market. By coupling predicted N 2O flux with the recently developed maximum return to N (MRTN) approach for determining economically profitable N input rates for optimized crop yield, we provide the basis for incentivizing N 2O reductions without affecting yields. The protocol, if widely adopted, could reduce N 2O from fertilized row-crop agriculture by more than 50%. Although other management and environmental factors can influence N 2O emissions, fertilizer N rate can be viewed as a single unambiguous proxy-a transparent, tangible, and readily manageable commodity. Our protocol addresses baseline establishment, additionality, permanence, variability, and leakage, and provides for producers and other stakeholders the economic and environmental incentives necessary for adoption of agricultural N 2O reduction offset projects. © The Author(s) 2010.