Nitrogen is essential to plant growth and animal production. Large quantities of fertilizer are needed to produce the main crops in the United States, including corn, soybeans and wheat. Many of these crops provide essential feed for animals. Much of the nitrogen consumed by animals is excreted, and the manure can be used to fertilize crops. However, large losses of nitrogen occur during this cycling. While the loss of nitrogen is difficult to quantify because it occurs through both the air and water, a full understanding of nitrogen loss is needed to ensure U.S. agriculture is resilient to changing weather patterns and economic pressures.
FarmFlux will quantify the loss of nitrogen to the atmosphere and track its downwind fate. From the perspective of the atmosphere, agriculture is the single largest source of ammonia (NH3), methane (CH4), and nitrous oxide (N2O) in the U.S.(EPA, 2017, 2022), and agricultural soils are an increasingly important source of nitrogen oxides (NOx) (Geddes et al., 2022). NH3 is a major precursor to particulate matter (PM), and soil NOx emissions are a precursor to tropospheric ozone (O3), both of which are criteria pollutants (EPA, 2020a, 2020b). Current estimates attribute over 10,000 deaths per year in the U.S. to agricultural PM (Domingo et al., 2021). CH4 and N2O are greenhouse gases, and N2O contributes to destruction of ozone in the stratosphere. Thus a full coupled understanding of the agricultural-atmospheric interface is important for clean air and planetary health.
The agricultural economy is also highly sensitive to air quality. For example, near-surface ozone damages crops, leading to billions of dollars per year in yield loss (WMO, 2023). Farm workers are especially susceptible to adverse health effects from agricultural emissions, and air pollution reduces productivity by economically meaningful amounts (Hill et al., 2023). Air pollution and temperature impact dairy cow production and health (Beaupied et al., 2022; Cox et al., 2017).
Food security is central to our prosperity, as is the health and wellbeing of our communities and the planet. To develop effective agricultural and environmental policy, we must understand the coupling of the agricultural and atmospheric systems. Current observations at the agriculture-atmosphere interface are sparse and not sufficient to properly evaluate emission inventories or improve predictions of future impacts. In particular, we have an incomplete grasp of how processes central to nitrogen cycling will respond to different farming management practices and changing weather patterns.
