Magnesium status of soils

Abstract

The magnesium status of the soils of Kerala was studied. In general, they were deficient in total Mg reserves (61 per cent of the soils studied). Altogether, 17 per cent of the soils were deficient in available Mg and 25 per cent deficient in exchangeable Mg. Black soils were rather rich in total Mg, available Mg and exchangeable Mg. The most deficient were the sandy loam soils of coastal alluvium. The laterite group was in between. The inter-relati onships among total, available and exchangeable Mg were found to be significant and positive. Exchangeable Mg correlated positively with other exchangeable cations. About 24 per cent of the total Mg reserve in the soils under study is considered available and 11 per cent exchangeable. The total Mg reserves in Kerala soils are found to be poor and Mg can be considered as a critical element in these acid soils