An experiment was conducted to assess the changes in different pools of soil K due to cropping in an Alfisol of West Bengal with rice and potato grown in two successive seasons in a year. Result showed that there was a general decline in the reserve pool of soil K at the harvest of rice, particularly at no or lower rates of applied K. When potato was grown as a succeeding crop, decline in the plot receiving no fertilizer K was 22.8% at the harvest of potato. It is concluded that at the recommended dose of fertilizer K, mining of native K under rice-potato crop sequence would be to the extent of 9%, which could be reduced by applying higher rate of K than the recommended level. This will help in sustaining the productivity of these crops. The Q/I parameters measured after harvest of both the crops supported the depletion pattern of K.
Non-exchangeable K, Alfisol, uptake, yield, rice, potato
