Cumulative, Direct and Residual Effects of Phosphorus, Potassium and Farmyard Manure on Crop Yield and Soil Characteristics

Results obtained from a field experiment conducted on bajra (pearl millet)-wheat sequence for 8 years have shown that mean responses of the order of 5.6, 5.5, 4.9 q/ha in bajra and 13.2, 12.1, 10.0 q/ha in wheat were obtained with 60kg P₂O₅/ha when applied as cumulative, direct and residual phases of manuring, respectively. Direct and residual effect of 15 t/ha FYM in both the crops were equivalent to 30 kg P₂O₅/ha with the same mode of application. Cumulative use of 60kg P₂O₅/ha dose raised the available P level in soil from 17 to 28.6kg P/ha at the end of the experiment. Available N and K status decreased with continuous cropping from 215 to 132 kg/ha and 616 to 256kg/ha, respectively. Potassium application did not show any significant effect on these attributes.