Effect of FYM and n levels on spinach yield, N-use efficiency and soil fertility in potato – spinach sequence

A field study was conducted at Shimla during 2002–03 to 2004–05 to work out the farmyard manure (FYM) and N requirement of spinach and its effect on soil fertility in potato - spinach sequence. Residual effect of 30 t FYM, 150 kg N, 83 kg P and 43.7 kg K/ha applied to potato resulted in saving of 25 kg N/ha in spinach. However, application of recommended FYM (10 t/ha) was essential to achieve potential yield of spinach. The partial factor productivity (PFP) of applied N in spinach showed a declining trend with increasing N rates but showed an improvement when FYM was applied. The mean values of PFP in the absence and presence of FYM were 0.29 t and 0.42 t/kg N, respectively. Agronomic and physiological efficiencies also increased in the presence of FYM. Nutrient balance and NPK status of soil improved over three years period.