SOIL FERTILITY MANAGEMENT INVESTIGATIONS ON A RHODIC PALEUSTULT IN SOUTH WESTERN NIGERIA

Abstract

A trial was carried out at Isoya in south-western Nigeria to determine the effect of N, P and K applications and weeding on the yield potential of maize grown and the Itagunmodi soil series. This soil is classified as clayey, oxidic, isohyperthermic, Rhodie Paleusfult. Following a short-mixed fallow cycle of four years, N and P responses were observed in the first year of cropping and K response in the second cropping year after land clearing. The soil which has a moderate P sorption capacity is very deficient in P. Results of incubation studies showed that under laboratory conditions about 5 ppm of fertilizer P was required increase the gray P-l test level by 1 ppm. High maize yield of above 4.6 tons/ha was obtained with variety TZPB during the first season and above 2.0 tons with variety TZE in the second season with weeding. The maize crop can compete effectively with weeds under high fertility.