Patterns Of N Loss In A Nigerian Soil

An experiment was conducted on a bare well drained soil of the Apomu Series, classified as a Quartzipsamment (USDA). The loss patterns of 100kg N ha-l of ammonium sulphate, sulphur coated urea (SCU) and urea were compared during ten weeks in the rainy season. After approximately 2Smm of rainfall the soil was sampled at l5cm intervals down to 90cm. Measurements of the inorganic N (NH4-N and N03-N) showed: a) SCU had no advantage over the other forms of N used, b) there was little evidence of leaching, c) volatile losses were possible during the first seven days after addition and could have been 29% and 71% for ammonium sulphate and urea respectively; and d) all the added N was lost by 40 days after addition. ----- Se realizd' una experiencia en un suelo raso bien drenado de la serie Apomu, con clasificacidn de Quartzipsamment (USDA). Se compararon los patrones de perdida de 100 kg Nha-1 de sulfato de amonio, de urea revestida de sulfato (SCU) y de urea por diez semanas dudante la estaci6n lluviosa, Tras aproximadamente 2Smm de precipitacion, se tom6 muestras del suelo a intervalos de IScm de profundidad hasta 90cm. Las mediciones del N inorgfinico (NH4 N Y N03 - N) demostraron que: (a) la SCU no ofrecfa ninguna ventaja comparada a las otras formas de N que se utilizaron; (b) habra poca evidencia de desalacidn; (c) habra una posibilidad de perdidas por evaporaci6n durame,los primeros siete dias posteriores a la aiiadidura. Estas nudieron haber sido del 29% en el caso del sulfato de amomo y del 71% en el caso de la urea; y (d) la totalidad del N aiiadido se perdi6 dentro de los 40 dias posteriores a la afiadidura.