Application of Taxonomic Classification in Soil Fertility Management Using Maize (<i>Zea mays </i>L<i>.</i>) as Test Crop in Alfisols of Makurdi, Benue State

Abstract

The Alfisols of Makurdi Local Government Area of Benue State was studied with the aim to characterize and classify the soils and determine the optimum fertilizer rate for maize production on the selected soil type of the study area. The soils were formed on Makurdi sand stone, deep (141 cm) and well drained. They were coarse-textured and moderately acidic in reaction (pH 6.6 – 7.0). They had low organic carbon contents ranging from 3.36 to 3.78 % and high base saturation of 58.6 % to 77.4 %. Based on the physical and chemical characteristics, the soils were classified as Eutric Ochrustalfs/Eutric Luvisols. In terms of growth parameters; plant height and number of leaves were not significantly different while leaf area, leaf area index and the stem diameter were significantly different. The highest (130.60 cm, 12.30 and 79.88 mm) plant height, number of leaves and stem diameter were observed at the rate of NPK 150:75:75 kg/ha of fertilizer. In terms of yield parameters, ear weight and grain yield were not statistically significant whereas, ear length and ear diameter were statistically significant. However, NPK 60:30:30 kg/ha showed the highest (178 g) ear weight while application of NPK 150:75:75 kg/ha gave the highest (2.82 kg) grain yield. Since there was no significant difference between the fertilizer rates, it could be concluded that the minimum application rate (NPK 60:30:30 kg/ha) should be used in cultivating maize in Alfisols of Makurdi instead of the highest or the blanket recommendation which involved higher cost.