CHARACTERISTICS AND CLASSIFICATION OF SOILS OF A REPRESENTATIVE TOPOGRAPHIC LOCATION IN THE UNIVERSITY OF AGRICULTURE, ABEOKUTA

Abstract

Detailed soil and landuse maps of an area approximately 32.592ha, along a representative topographic location in the University of Agriculture, Abeokuta were produced for effective landuse planning. The site is underlain by Basement Complex rocks with quartz schist, coarse grained and fine grained granite and gneiss  as parent material. Thirteen soil series were identified with soil properties varying within short distances from upper slope to valley bottom. Soil textual class ranges from sand to sandy clay loam with percent gravel ranging from 8.67 to 46.84. Soil reaction is almost neutral (pH 6.06—6.73) with moderate to high available phosphorus (5.85 to 22.95 ppm) and High base saturation (704-93.20%). The coefficient of variability for soil properties ranges from 4.10 to 63.69% with 63.69% for % clay; 57.37% for % gravel; 32.61% for Ca⁺⁺ me/100g soil; 32.31% for % C, 30.33% for profile depth and 29.03% for Available P.  Soil mismanagement in the area is reflected in the degeneration of fallow vegetation consisting mainly of Imperata cylindrica and Chromolaena odorata as the land is presently cultivated without regard for soil properties. Ekiti, Okemesi and Gambari series are recommended for pasture; Egbeda and Iwo series for cocoa and kola; Ibadan, Apomu, Iregun and Balogun series for arable cropping; Adio, Matako and Ikire series for dry season cultivation of arable crops and vegetables while Oshun series should be left to swarmp forest and fish cropping. Land suitability classification is however essential for optimum crop production and soil management. The soil were classified into Alfisols and Entisols of the USDA classification with corresponding FAO classification.