Exchangeable potassium (K+) was the highest (0.14 Cmol kg 1 in topsoil and 0.12 Cmol kg 1 in the subsoil) under cultivated land and the lowest (0.03 Cmol kg 1 in topsoil and 0.02 Cmol kg 1 in the subsoil) under bush land (Table 2). The percent20 age changes in K+ content of subsoil from topsoil were decreasing in all land uses.
The change was the highest in grazing land ( 58 %) and the lowest in cultivated land ( 14 %), while it was intermediate in the forestland ( 54 %) and bush land ( 33 %) (Fig. 2). The highest content of K+ under cultivated land in both sampled depths may be related to frequent supply of fertilizers i.e. urea and DAP (up to 100 kg ha 1 each) 25 applied to cultivated land. Whereas, the lowest value of K+ in both sampled depths under bush land was attributed to high browsing, erosive nature of the soil (sandy soil) and high level erosion (Table 1). In addition, the highest variability of K+ with depth under grassland may be attributed to cattle manure supplied to the topsoil.