Accumulation and Decline of Available Phosphorus and Potassium in a Soil under Multiple Cropping

Accumulation and decline of avail. P and K in the soil were measured after two cycles of crop rotation in a multiple cropping system. The initial low status of avail. P improved to medium or high levels commensurate with the rates of fertilizer P application. However, initially low status of avail. K of the soil remained as such with all the rates (50, 100 and 150 per cent of the optimum soil test based dose) of potash fertilization. The status of avail. P and K further declined where fertilizer P and K were not being added.