EFFECTS OF TILLAGE AND NITROGEN FERTILIZATION ON SOIL ORGANIC CARBON AND MAIZE PERFOMANCE IN THE SOUTHERN GUINEA SAVANNA OF NIGERIA

Abstract

The study evaluates the effects of tillage and split nitrogen fertilization on soil organic carbon and maize performance in the rainy season of 2022 at Anyigba, southern Guinea savanna agro ecological zone of Nigeria. The treatments were tillage practices with two levels, manual ridging (MR) and minimum tillage (MT) and split nitrogen fertilization with five levels 0, 30 + 60, 45 + 45, 60 + 30 kg N ha^-1 applied in split form at 2 weeks after planting and at tasseling growth stage and 90 kg N ha^-1 full dose applied at 2 weeks after planting. The experimental design was 2 x 5 factorial fitted to randomized complete block design with three replicates. The results showed that there was no significant effect of the treatments on seedling emergence. Manual ridging recorded significantly higher soil organic carbon content with mean value of 28.72 g kg^-1 at 2 weeks after planting compared with minimum tillage. Tillage significantly affected maize grain yield with MR recording 1.3 Mg ha^-1 which was significantly higher than 1.2 Mg ha^-1 recorded for MT.  There was response to N fertilization with the N fertilized treatments having significantly higher grain yield than the control treatment. The split application of N, 60 + 30 kg N ha^-1 produced the highest grain yield of 2.2 Mg ha^-1 which was significantly higher than of the split, 30 + 60 kg N ha^-1 and the zero N treatment. Manual ridging and split application of recommended rate of N seem to be the most appropriate for maize production in the area.