1Division of Agronomy and Soil Science, Central Potato Research Institute, Shimla-171 001, (HP).
Publication No. 1588, CPRI, Shimla.
Controlled pot study using labelled superphosphate was conducted during 1996 on acidic soil of Fagu (Shimla) to investigate the effect of farmyard manure on P use efficiency in potato (Solanum tuberosum L.) and also the residual effect on succeeding barley crop (Hordeum vulgare L.). Combined application of P and FYM had a significant effect on potato dry matter yield and P-uptake as compared to control and was better than their application alone. The beneficial effects were also reflected in higher radioassay values, viz. 7.6 and 23.9 percent for % Pdff and % P utilization, respectively. This was also supported by the autoradiograph of the potato roots which indicate presence of dense root mass with FYM+P.
The residual effect of P on succeeding barley was substantial and was highest in presence of FYM+P. The radioassay data showed that barley was able to utilize 3–6% of residual P within 30 days of plant emergence. The residual effect of FYM alone was, however, non significant.
