Crop Yield Potentials of The Inland Valleys of Ibadan Urban Area, South Western Nigeria
Increasing demands on agricultural and potential agricultural lands for other uses, especially in the urban environment is necessitating the investigation of flood prone low lands, especially inland valleys for agricultural production. This is for the purpose of supplementing rainfed crop production of the uplands. Inland valleys are the least attractive to urban development. Incidentally, those characteristics that make inland valleys less attractive to urban development confer on them high potential for agricultural uses. This work investigated the crop yield potentials of some of the inland valley soils in Ibadan urban environment. Maize and Okra were used as the test crops. The selection of the sites was based on geological origin, valley shape and whether forested or not forested. The soils of the inland valleys are generally young (Entisols/Gleysols). They are slightly acidic to neutral with high base saturation and moderate to high nutrient status. Water-table depth determines to a large extent their usefulness. At low management levels (no fertilizers), yields of 4.6 t/ha and 7.5 t/ha were obtained for maize and okra respectively. At improved management levels (fertilized), yields were much higher: 6.8 t/ha and 13.3 t/ha for maize and okra respectively. Poor drainage and high weed infestation despite moderate to high fertility status are constraints for optimum usage of the inland valley soils, especially in the rainy season. Adequate exploitation of the potentials of these inland valleys for crop production, especially during the dry season, will go a long way to supplementing the food requirement of the urban dwellers.
Keywords: Inland valley soils, Crop yield, Alluvial deposits, Fertilized and non-fertilized plots, maize, Okra