Abstract

A detailed soil survey of the Laccadive Islands, a group of nineteen islands off the West Coast in the Arabian Sea, brought to light the presence of large deposits of phosphorus. These deposits have a high content of calcium carbonate and are low in organic matter. Phosphorus is present in the citric soluble form and in spite of the high content of calcium carbonate present in the deposits, reversion of phosphorus to insoluble forms does not take place. The absence of ammoniacal nitrogen must be due to the presence of calcium carbonate and the nitrate nitrogen, if any, must have been washed off. The origin of the phosphate deposits in the Laccadives is not definitely established. It is presumed that the accumulation of birds' guano through centuries must have enriched the soil with phosphorus and calcium. If the Laccadive phosphate could be used as a substitute to the ordinary phosphatic fertilisers, it will go a long way to ease the current fertiliser shortage threatening the country's agricultural production plans. Hence it was felt feasible to compare its efficiency as a 'fertiliser' with one of the commonly used chemical fertilisers

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