http://oar.icrisat.org/id/eprint/8166 2014-07-08T05:41:58Z info:eu-repo/semantics/descriptiveMetadata http://oar.icrisat.org/8166/ Initial and residual effects of nitrogen fertilizers on grain yield of a maize/bean intercrop grown on a Humic Nitosol and the fate and efficiency of the applied nitrogen Ssali, H Agriculture-Farming, Production, Technology, Economics Fertilizer Applications Initial and residual effects of nitrogen (N) fertilizers on grain yield of a maize/bean intercrop grown on a deep, well-drained Humic Nitosol (66% clay, 3% organic carbon) were evaluated. Enriched (15N) N fertilizer was used to study the fate of applied N in two seasons: using urea (banded) at 50 kg N ha−1 in one season, and15N-enriched urea (banded), calcium ammonium nitrate (CAN, banded), and urea supergranules (USG, point placement) were applied in the other season (different field) at 100 kg N ha−1. Nitrogen fertilizer significantly (P = 0.05) increased equivalent maize grain yield in each season of application with no significant differences between N sources, i.e., urea, CAN, and USG. Profitmaximizing rates ranged from 75 to 97 kg N ha−1 and value: cost ratios ranged from 3.0 to 4.8. Urea gave the highest value: cost ratio in each season. Most (lowest measurement 81%) of the applied N was accounted for by analyzing the soil (to 150 cm depth) and plant material. Measurements for urea, CAN, and USG were not significantly different. The high N measurements suggest low losses of applied N fertilizer under the conditions of the study. Maize plant recovery ranged from 35 to 55%; most of this N (51–65%) was in the grain. Bean plant recovery ranged from 8 to 20%. About 34–43% of the applied N fertilizer remained in the soil, and most of it (about 70%) was within the top soil layer (0–30 cm). However, there were no significant equivalent maize grain increases in seasons following N application indicating no beneficial residual effect of the applied fertilizers Kluwer Academic Publishers 1990 Article PeerReviewed application/pdf en http://oar.icrisat.org/8166/1/FertRes_23_63-72_1990..pdf Ssali, H (1990) Initial and residual effects of nitrogen fertilizers on grain yield of a maize/bean intercrop grown on a Humic Nitosol and the fate and efficiency of the applied nitrogen. Fertilizer Research, 23 (2). pp. 63-72. ISSN 0167-1731 http://dx.doi.org/10.1007/BF01063332 info:eu-repo/semantics/objectFile info:eu-repo/semantics/humanStartPage