A long-term fertility field experiment (1978179 - 1996/97) in rice-wheat-fallow cropping system was conducted at Regional Agriculture Research Station (RARS), Tarahara to evaluate the effict of organic and inorganic manure on the grain yield of rice and wheat as well as chemical properties of soil. The application of 100 kg nitrogenlha was found in negative relation with the grain yield of rice and wheat, while it had positive to the application of 50 kg nitrogenlha under Tarahara condition. Similarly the response of phosphorous in combination with nitrogen alone or with potash attained positive effect of grain yield showing 30 kg of phosphorous and potashlha were inadequate dose for rice crop. The positive response of both of phosphorous and potash indicated to be verified for their accurate combination and dose for optimum yield The application of 30 and 40 kg of phosphorous and potash in combination with sole nitrogen or with each other nutrients, the response was positive but not peifect. The effict on soil properties, the pH was found decreasing less in the field supplied with combination of nitrogen, phosphorous and potash than any single or double major nutrients applied plots. Organic matter increased even without any external supplementation of any nutrients and also the percentage of nitrogen was found increasing which was recorded as higher in the plots supplied with combined nutrient application rather than the application of any one or two major nutrients. Similarly the external supply of phosphorous and potash was found as not properly substituting the quantity that was removed by rice and wheat crops in the experiment.

A long-term fertility field experiment (1978179 - 1996/97) in rice-wheat-fallow cropping system was conducted at Regional Agriculture Research Station (RARS), Tarahara to evaluate the effict of organic and inorganic manure on the grain yield of rice and wheat as well as chemical properties of soil. The application of 100 kg nitrogenlha was found in negative relation with the grain yield of rice and wheat, while it had positive to the application of 50 kg nitrogenlha under Tarahara condition. Similarly the response of phosphorous in combination with nitrogen alone or with potash attained positive effect of grain yield showing 30 kg of phosphorous and potashlha were inadequate dose for rice crop. The positive response of both of phosphorous and potash indicated to be verified for their accurate combination and dose for optimum yield The application of 30 and 40 kg of phosphorous and potash in combination with sole nitrogen or with each other nutrients, the response was positive but not peifect. The effict on soil properties, the pH was found decreasing less in the field supplied with combination of nitrogen, phosphorous and potash than any single or double major nutrients applied plots. Organic matter increased even without any external supplementation of any nutrients and also the percentage of nitrogen was found increasing which was recorded as higher in the plots supplied with combined nutrient application rather than the application of any one or two major nutrients. Similarly the external supply of phosphorous and potash was found as not properly substituting the quantity that was removed by rice and wheat crops in the experiment.