Abstract:
A study was conducted to determine the distribution of forms of K (water soluble K, exchangeable K, non-exchangeable K, and total K) of potassium in some Ghanaian soils occurring along toposequence using standard laboratory procedures. The soils were the Edina, Atabadzi, Benya, Udu and Kakum series (Acrisols), which form the Edina catena. The concentrations of total K in the soils ranged from 0.64 to 2.37 (cmol (+) kg-1) with Kakum series showing the lowest (P < 0.05) value. Water soluble K and exchangeable K concentrations in the soils ranged from 0.05 to 0.25 c mol (+) kg-1, and 0.26 to 0.89 cmol (+) kg-1, respectively, with the Kakum series again showing the lowest values (P < 0.05) for both K forms. The Edina series, occurring at the summit of the catena, showed the highest concentrations of both water soluble and exchangeable K. In the study non-exchangeable K concentrations measured in the soils varied between 0.20 and 1.25 cmol (+) kg-1. The study showed that exchangeable K constituted the highest proportion of the total K measured in the soils, while the proportion of water-soluble K in the total K measured was the lowest. Pooling all the data obtained in the study, water soluble K and exchangeable K concentrations positively correlated with organic matter, cation exchange capacity and percentage bas saturation
