FIXED AMMONIUM IN NIGERIAN SOILS

In soil profiles from Nigeria native fixed ammonium was positively and significantly correlated with per cent silt, per cent clay, per cent silt plus clay, pH, exchangeable potassium and cation exchange capacity but not with exchangeable ammonium or organic matter. The results of multiple and partial regression analyses indicated that native fixed ammonium was most closely correlated with per cent clay, exchangeable potassium, and cation exchange capacity.