Effect of anhydrous ammonia with and without nitrapyrin applied fall and spring on corn yield

Abstract

Abstract Fall application of N for corn [Zea mays (L)] on clay pan soils in northeastern Missouri has not become an accepted practice as wet soils conductive to denitrification often delays corn plantings. Since nitrification inhibitors have the potential to reduce denitrification loss of fall applied N, a 4‐year study (1979–82) was conducted on a Mollic Albaqualf soil, subject to excessive spring wetness and representative of the corn growing region in northeastern Missouri to study the effect of the nitrification inhibitor, nitrapyrin, on fall and spring applied anhydrous ammonia. A randomized block design with 4 replications was employed using 0, 56, 112, 168 and 224 kg N/ha as anhydrous ammonia applied fall and spring with and without 0.56 kg/ha of nitrapyrin. Measurements included grain yield, leaf N and grain protein. The second year, 1980, high day and night temperatures and July rainfall 118 mm below normal eliminated any response due to N and nitrapyrin treatments. Grain yield, leaf N and grain p...