EVALUATION OF THE AVAILABLE PLANT NUTRIENTS AT DIFFERENT pH LEVELS OF AHOKOR CLAY DEPOSIT LOCATED IN KOGI STATE, NIGERIA.

Abstract

The nutrient level of Ahokor clay deposit in Kogi State, Nigeria was evaluated with the view of using it as a soil ammendments in soils deficient in plant mineral nutrients. Exchangeable bases (EB), cation exchange capacity (CEC), exchangeable acidity (EA) and percent base saturation were determined at five different pH levels for the top (LT) and bottom layers (LB) of the clay. These parameters were determined at pH4, pH5, pH7, pH8 and pH9 respectively. The exchangeable bases varied with change in pH with optimum values of K+ (1.120 0.300 cmolKg-1) and Na+ (0.701 0.010 cmolKg-1) for LT obtained at pH7 and pH4 respectively, while those of Ca2+ (0.920 0.025 cmolKg-1) and Mg2+ (0.298 0.027 cmolKg-1) were recorded at pH9. Optimum values for the exchangeable bases for the bottom clay (LB) were recorded at pH9 with values of 0.536 0.020 cmolKg-1, 3.522 0.023 cmolKg-1, 1.959 0.020 cmolKg-1 and 0.358 0.036 cmolKg-1 recorded for Na+ , K+, Ca2+ and Mg2+ respectively. The optimum condition for application as soil ammendment was obtained at pH9 as the percent base saturation which indicates that the crystal lattice is occupied with more of the desired base cations was highest at this pH for both layers.