SUITABILITY EVALUATION OF SOILS OF LOWER RIVER OSHIN FLOODPLAIN, KWARA STATE, NIGERIA FOR RAIN-FED ARABLE CROPS CULTIVATION

Abstract

The rapid population growth of Nigeria and the need to satisfy their food requirements have resulted in the cultivation of floodplains hitherto regarded as marginal lands for rain-fed agriculture. In a bid to generate adequate information that may aid optimal and sustainable exploitation of the soils of lower River Oshin floodplains in Kwara State, Nigeria, the FAO land suitability evaluation (LSE) for rain-fed maize and paddy-rice was used to evaluate the land. The total land area was 788 ha. Three soil units designated as OSH-1, 118 ha, OSH-2, 221 ha and OSH-3, 449 ha were identified. Maize and paddy-rice were the crops commonly cultivated by farmers in the area. The soil units, OSH-2 and OSH-3 had surface texture of sandy loam and bulk densities of 1.22 and 1.13 Mg m3 that favour good agricultural production. All the soils had medium to high fertility status with available P ranged from 10 - 40 mg kg-1, organic C, 27.5 – 35.5 g kg-1, and CEC, 19.14 – 21.99 cmol kg-1. None of the soil units rated highly suitable (S1) for both crops. Topography and P-fixation were the limiting factors controlling the choice of OSH-1 and OSH-3 respectively for paddy-rice, while drainage was the controlling factor limiting suitability of all the soil units for maize production. Generally, all the soils have enormous potential for rain-fed cultivation of rice and other arable crops that are intolerant to waterlogged soils, if adequate drainage is provided and problem of P-fixation in OSH-3 is properly managed.