Pronitridine and Nitrapyrin With Anhydrous Ammonia for Corn

Abstract

Nitrogen (N) losses due to leaching, denitrification and/or ammonia volatilization are of utmost concerns since they reduce farm profitability and adversely affect environmental quality. To combat these N losses, a new nitrification inhibitor (NI), pronitridine, can be used to slow down the nitrification process. A two-year (2014, 2015) field experiment was conducted to evaluate the effectiveness of pronitridine at different rates (9.4, 18.7, and 28.1 L ha-1) with anhydrous ammonia (AA) at 112 kg N ha-1 when applied in the fall or pre-plant on claypan soils in northeast Missouri. Using pronitridine at 9.4 L ha-1 with AA in the fall during a low yielding year (2015) increased corn grain yield 7% compared to AA + nitrapyrin (2.3 L ha-1). Agronomic efficiency and yields were greatest with pronitridine at 9.4 L ha-1 than AA + nitrapyrin. Grain N removal was highest for AA + pronitridine at 18.7 L ha-1 compared to AA + nitrapyrin. Pre-plant application of AA + pronitridine at 9.4 L ha-1 increased grain starch content compared to AA without NI, but it was not significantly different from AA + nitrapyrin. Results indicated that pronitridine was effective in increasing yields when applied in the fall and was similar to other NI’s when applied pre-plant in the spring.