Effect of Nitrogen and Sulphur Additions on the Availability of Manganese for Rice

Twelve soils with variable amounts of water soluble, exchangeable and easily reducible manganese content were used for growing rice in a greenhouse experiment with nitrogen alone and nitrogen plus stdphur treatments. The manganese content of the plant varied significantly from soil to soil, bearing a correlation (r=+0.72) to the water soluble plus exchangeable manganese of these soils. Nitrogen application induced increased uptake of manganese, and when extra sulphur was supplied as sulphate, it resulted in further significant increase in the manganese content of rice.