Does Biochar Improve Nitrogen Use Efficiency in Maize?.

Nutrient loss reduction strategies have been developed across the U.S. Midwest with the goal of substantially reducing nitrogen (N) losses from agriculture. Prior work has demonstrated the potential for biochar to reduce N losses and increase N use efficiency, yet little information is available for typical corn-soybean rotations in the Midwest. A two year field study was conducted to test the hypothesis that biochar application reduces N requirements for maize (i.e. equivalent yields are achieved at lower N rates), thereby increasing N use efficiency. Treatments included four inorganic N rates (0, 90, 179, and 269 kg ha^-1 as broadcast UAN) applied with or without biochar (10 Mg ha^-1) prior to planting. Soil inorganic N concentrations were monitored early in the season and crop yield and fertilizer use efficiencies were determined at harvest. Preliminary results indicate that biochar did not significantly increase soil ammonium or nitrate availability, yields, or N use efficiency at any of the N rates applied. This presentation will summarize two years of results.