Decreasing reactive nitrogen losses in organic agricultural systems

Excess reactive nitrogen (Nr) in the global system has led to a wide variety of environmental and human health problems. To minimize the negative impacts of nitrogen loss from agriculture, we need to develop more sustainable farming systems that can efficiently produce food for humans while balancing ecological functioning and reducing Nr losses. This paper looks at recent research examining Nr losses in organic systems, using conventional Nr losses in the United States (U.S.) as a baseline to identify leverage points for reducing Nr loss. The paper discusses the sources of Nr used in organic versus conventional farming and highlights the importance of increasing the use of recycled Nr to prevent additional Nr loss to the environment. Specifically, we note that organic production is advantageous when it comes to the creation of new Nr because of its reliance on recycled sources of Nr, improved ability to access nutrients in the soil, and higher residue recycling rates. We also highlight areas where additional research, policies, and protocols are needed to improve Nr efficiency, including increasing organic yields, increased recycling of processing waste, matching nutrient flows, reducing and recycling edible food waste, and examining potential benefits and risks of land application of sewage sludge in organic systems.