Abstract

Total magnesium obtained by summing up the four fractions of magnesium. namely, mineral magnesium, acid-soluble (reserve) magnesium, exchangeable magnesium and organic-complexed magnasium, was found to be as good as estimating total magnesium separately. The pattern of distribution of magnesium in the Nilgiris depended largely on rainfall which influenced indirectly through its manifested effect of pH. base saturation, exchangeable aluminium and total acidity which are interrelated among themselves. Wide variations may also be attributed to the parant materials which varied even within a small area. charnockite the parent rock of most Nilgiris soils which is known to vary considerably from acid to ultra basic conditions. Increase in clay content of the soil was found to increase total My as weil as magnesium fractions, Among other parameters, organic carbon, moisture. pH. total acidity, exchangeable H. E. C. and base saturation were also observed to influence the pattern of distribution.

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