Enlisting the “Weatherman” in Decisions about Enhanced Efficiency N Fertilizers.

Enhanced efficiency nitrogen fertilizer products use nitrification inhibitors, urease inhibitors, and polymer coatings to delay conversion into plant-available forms of nitrogen (N) that are also at high risk for denitrification and leaching losses. While individual studies have examined the effectiveness of these products in certain locations and cropping systems, we don’t fully understand the impact of near-term weather (temperature and precipitation) on the yield benefits and N losses. Using a parameter that depicts precipitation abundance and distribution into a single factor, and another parameter for temperature, we explore the effects of near-term weather (2 weeks prior and 2 weeks following fertilizer application) on the yield and loss responses to various enhanced efficiency N fertilizers. The source data are all available published studies of corn and wheat in North America that test relevant EEFs. The resulting meta-analysis also considers management and soil factors.