Suitability Assessment of Soils for Oil Palm Cultivation in Ofunwengbe, Ovia North East Local Government Area of Edo State, Nigeria

Abstract

The aim of the study was to determine the suitability of an18 hectare piece of land situated in Ofunwengbe Village Area, Ovia North East Local Government Area of Edo State, Nigeria for oil palm cultivation. Field survey was made along the transverses for physical, morphological and landscape examination. Also, surface and subsurface soil samples were collected in addition to relevant climatic data for suitability and fertility evaluation. The soil samples collected were analyzed in the laboratory using standard methods.The vegetation consists of primary forest, the topography ranged from flat to undulating / sloppy with elevation above the sea level of greater than 100 m. The soil ranged from sandy loam to loamy sand with increase in clay content with depth. The effective soil depth is greater than 90 cm (rooting zone) and the soil is well drained and free from hard pan and impediment. Temperature, sunshine hours, relative humidity and rainfall amount are adequate for oil palm establishment but number of dry months is marginal for oil palm production. The pH of the soils ranged from acid (4.7) to slightly acid (5.9). The percentage organic carbon content was generally low than 0.8% in the entire site. Similarly, the nitrogen content was considerably low in all the examined points, with the values ranging from 0.002% to 0.008%. Available phosphorus content ranged from very low (6.4 mg/kg) to very high (33.92 mg/kg). Exchangeable magnesium was generally high (greater than 0.2 cmol/kg) in all the examined points; hence magnesium is not a limiting factor for oil palm production in the site. However, exchangeable potassium was generally low (less than 2.0 cmol/kg) in all the examined points. Thus, the values fall below the recommended level especially for oil palm cultivation. Effective Cation Exchange Capacity (ECEC) was very low < 10 cmol/kg. This falls below the requirement for oil palm production. The results indicated that the site had good potential for oil palm production. Therefore, in order to improve the condition and raise the productivity of the land to optimum level, planting of cover crops and application of organic residue like empty fruit bunches (efb) should be considered to compensate the soil moisture deficit during the dry month when the production of fresh fruit bunch commence.The soil reaction level (pH) is adequate for nutrient availability. The main fertility constraint is the low effective cation exchange capacity (ECEC), low level of nitrogen (N) and exchangeable potassium (K). These can be augmented by the addition of appropriate fertilizer and proper timing from field establishment to fruit-bearing period.