STUDY OF MANGANESE OXIDES AND HYDROXIDES DITRIBUTION IN SOME CALCAREOUS SOILS IN NINEVEH PROVINCE EXTRACTED BY DIFFERENT DISSOLUTION METHODS.

Forty soil samples from eight profiles were chosen to represent Al-Fadhilia , Kara-Tapa and Al-Hamdania regions, in Nineveh Province . Three selective dissolution methods were used to extract the different manganese phases DTPA , DCB and GAc. The results indicated that GAc, method was effective in extracting manganese adsorbed on calcium carbonates and clay surfaces ranged 38.78 - 47.74 mg.Kg-1 soil, DCB method was effective in dissolving manganese oxides especially in the thin black deposits and in Mn-Fe concretions was in second order ranged 11.78 - 39.9 mg.Kg-1 soil , while DTPA method was the lowest in extracting available manganese ranged 0.9 - 3.34 mg.Kg-1 soil.