Evaluation of sulphur-coated urea fertilizers in savannah soils: 1. Response of cotton and sorghum

Abstract

SUMMARYTwo sources of sulphur-coated urea (SCU) were compared with calcium ammonium nitrate (CAN) as sources of N for cotton and sorghum in the savannah zone of Nigeria. At the lowest rate of N application (30 kg/ha for cotton and 40 kg/ha for sorghum), SCU-11 with a dissolution rate of 11% in 7 days was found to be more effective than SCU-30 having a dissolution rate of 30% in 7 days and CAN. A single application of SCU-11 produced a higher sorghum yield than a divided application of CAN at the same rate. These results indicate that a slow-release nitrogen fertilizer might be useful for improved grain sorghum and cotton varieties.