Reducing nitrogen losses in a changing climate

This project evaluated the efficacy of Pivot Bio’s designer microbe product (PROVEN®) in reducing reactive nitrogen losses from corn systems and its impact on overall plant health and productivity. Here, we tested nitrogen-fixing BI (PROVEN and PROVEN 40, Pivot Bio) and evaluated its efficacy to produce a sustainable corn (Zea mays L.) yield over a range of fertilizer rates (FRs) and examined its impact on N2O emissions. The experiments were conducted over seven seasons in an indoor mesocosm facility. The results indicate that the BI treatment did not have any significant effects on N2O emissions, yield, leachate, soil or plant N concentrations, or nitrogen use efficiency. Fertilizer rate showed a significant relationship for increasing N2O emissions, increasing soil N concentrations, and decreasing NUE. Nitrous oxide emissions increased linearly with increasing FR from 81 to 404 kg N ha-1. Overall, the results indicate that BIs did not effectively mitigate N2O emissions or improve yield.