Studies on the Distribution and Availability of Micronutrients in Maharashtra Soils I. Manganese

Representative surface soil samples were collected from six agro-climatic zones of the Maharashtra State and their manganese fractions were estimated. The ranges for available, easily reducible, active and HCl-soluble manganese were 1.5 to 67.0 ppm, 88.0 to 516.0ppm, 102.5 to 520.0 ppm and 250.0 to 1652, 5 ppm respectively. In general, the soils from arid to semi-arid and transition zones were richer in their active manganese status in comparison with the laterites. The acid soils contained more available manganese than the black soils. Rainfall was the most potent factor to increase available manganese, Higher the pH and CEC, lesser was the available manganese and vice versa. The easily reducible, active and HCl-soluble forms increased with the increase in silt plus clay fractions of soils. The possibilities of probable deficiency and toxicity of manganese appear to exist respectively in the neutral to alkaline soils and laterite soils of the western belt of the State.