Climate Solutions: Biological Nitrification Inhibition in Modern Crop Varieties

Abstract:

Investigating low-nitrifying sustainable farming systems is essential as current agriculture accounts for approximately 80% of total anthropogenic emissions of nitrous oxide, a highly potent greenhouse gas (GHG) that has also become the largest ozone depleting substance in the atmosphere. It is estimated that only about 30-50 percent of applied N-based fertilizers is utilized by crops. The remainder is lost through various mechanisms and becomes environmental pollutants through nitrification, denitrification, leaching or runoff. Nitrous oxide is an intermediate product that is released during microbial nitrification and denitrification processes. Some plants can suppress nitrification by releasing specific root exudates that inhibit soil nitrifier activity and production of nitrates (NO3-) in soils (a property called biological nitrification inhibition, BNI). The practice of applying abundant amounts of nitrogen fertilizers to agricultural crops has generally made nitrogen easily available but, in the process, has largely removed these genetic traits that were
critical in protecting soil-nitrogen from losses. Breeding for high BNI activity could be an effective and innovative strategy for developing long-term solutions for improving environmental sustainability of agricultural practices. In this presentation, we will provide an overview of BNI, current international research collaborative effort on BNI, preliminary findings of BNI in sorghum (sorghum bicolor), and the potential of low-nitrifying BNI production systems for improving environmental sustainability of agricultural practices in the U.S. and around the globe.