Cations Ratios Distribution in Selected Rice Soils of Ebonyi, Southeastern Nigeria

This research work was carried out on the rice soils of Ebonyi State, considering the cation ratios distribution in upland, lowland and irrigated rice in the three agro-ecological zones of Ebonyi, namely; Ebonyi North, Ebonyi Central and Ebonyi South. The location at Ebonyi North was at Amachi Izzi in Abakaliki and designated by AUP, ALP and AIP for Abakaliki Upland, Lowland and Irrigated pits respectively. Ebonyi Central was located at Ikwo and designated by IUP, ILP and IIP for Ikwo Upland, Lowland and Irrigated pits respectively. Ebonyi south located at Ivo and designated by IvUP, IvLP, and IvIP for Ivo Upland, Lowland and Irrigated pits respectively. Each of the rice land utilization types were delineated, and three profile pits dug in each of the rice land uses to investigate the distribution of cations ratios for optimal yield and growth of the rice plant. The cation ratios that were investigated include; Ca/Mg, K/Mg, Ca+Mg/Al+H and Ca/Al. The Ca/Mg ratios of Ebonyi central were the highest at the three different agro-ecologies. The highest means occurred at ILP1 (10.61:1) followed by IUP1 (9.14:1), IIP3 (8.13:1) and ILP3 (7.39:1). Also at Ebonyi south rice soils, Ca/Mg ratios were as follow; IvUP 1 (7.78), IvIP1 (6.87), IvUP2 (8.36) and IvIP2 (8.12). The mentioned pedons have the Ca/Mg ratio within the acceptable range of 6.5 according to Grahams Model of Basic Cation Saturation Ratios, although they fall below Loides recommendation of (10-20). K/Mg ratios of all the investigated soils were low when compared to the acceptable limits of 0.5 according to Grahams Model, as means were less than 0.5 in all the investigated soils of Ebonyi north, central and south. Analysis of variance of Ca: Mg, K:Mg, Ca+Mg: Al+H and Ca: Al showed that they were significant (0.05% level of probability) at the different rice zones (locations) and landuses, although Ca+Mg: Al+H indicated non-significant at the landuses. However when the interactions of different factors were considered, Ca: Mg was significant at location X pedons and non-significant at location X landuse, landuse X pedons, and location X landuse X pedons. K:Mg was significant (0.05% probability) at location X landuse, location X pedons and location X landuse X pedons and non-significant at landuse X pedons.