Soil Nutrient Status of the Fresh Water Swamp at the NIFOR Raphia Hookeri Outstation, Otegbo

Abstract

Soil nutrient status of the Fresh Water Swamp at the NIFOR Raphia hookeri outstation, Otegbo was studied. Samples were obtained from mini pits sunk at two plantations in the study area. The collected samples were air-dried at room temperature for seven days and analyzed for physico-chemical properties in the laboratory using standard methods. The results showed that clay increased significantly with increased depth in both plantations while sand decreased significantly with increased depth in both plantations. Silt however decreased significantly with increased depth in plantation 1 and decreased not significantly with increased depth in plantation 2. The silt/ (silt + clay) ratios were all less than unity. Soil nutrient status was generally low as revealed by their estimated levels of availability. Organic carbon, Nitrogen and Phosphorus decreased with increased depth. Though Potassium was the same at both the top and subsoil in plantation 1, it however decreased not significantly with increased depth in plantation 2 Mean soil pH of between 5.55 in the top soil and 5.85 in the subsoil seemed optimum as revealed by the positive and significant correlation of soil pH with ECEC with (r = 0.803, p< 0.01) and negative correlation of ECEC with soil pH between 5.47 in the top soil and 5.61 in the subsoil with r = -0.286 in plantation 2. This study however revealed that the Fresh Water Swamp soil nutrient status can be improved for Raphia hookeri cultivation by appropriate soil organic matter management as well as enhanced sand and silt weathering.

Key words: Fresh water swamp, NIFOR, Raphia hookeri, Otegbo.