Influence of Intensity of Soil Reduction on the Availability of Iron, Manganese and Phosphorus and the Growth and Nutrition of Rice

The influence of intensity of soil reduction on the availability of iron, manganese and phosphorus and the growth and nutrition of rice was investigated. The different intensities of reduction were created by applying starch at the rate of 0, 0.25 and 0.50 per cent to the soil. The availability of iron, manganese and phosphorus was highest in the soils which were treated with 0.50 per cent starch. Plants grown under this treatment recorded highest dry weight and also absorbed highest amounts of iron, manganese, phosphorus and nitrogen. The beneficial effect of this treatment on the growth and nutrition of the plants was possibly due to the capacity of the higher state of reduction, as was developed in presence of decomposing organic matter, to maintain a higher amount of iron, manganese and phosphorus in available form in soil.