Long-term soil fertility experiment has been conducted at National wheat Research Program to evaluate the effects of long-term application of fertilizer and manure on soil fertility in a Rice-Rice-Wheat system. Nine fertilizer treatments including F. Y.M were tested Sharp yield decline was observed in minus P treatments. Yield decline was severe in early rice compared to normal Rice, and wheat. In minus P treatments yield came down to zero by 5th year. Yield reduction in minus K treatments was not observed in early rice but there was significant yield reduction in Normal Rice and Wheat. Reduction in available P seems to limit the grain yield followed by Potassium. F. Y.M increased almost all soil properties except exchangeable K. Despite the increase in soil properties in F. Y.M plots, yield could not sustain. Application of P and K, regained almost the original yield in P and K deficient plots.

Long-term soil fertility experiment has been conducted at National wheat Research Program to evaluate the effects of long-term application of fertilizer and manure on soil fertility in a Rice-Rice-Wheat system. Nine fertilizer treatments including F. Y.M were tested Sharp yield decline was observed in minus P treatments. Yield decline was severe in early rice compared to normal Rice, and wheat. In minus P treatments yield came down to zero by 5th year. Yield reduction in minus K treatments was not observed in early rice but there was significant yield reduction in Normal Rice and Wheat. Reduction in available P seems to limit the grain yield followed by Potassium. F. Y.M increased almost all soil properties except exchangeable K. Despite the increase in soil properties in F. Y.M plots, yield could not sustain. Application of P and K, regained almost the original yield in P and K deficient plots.