Site specific NPK recommendation in wheat (Triticum aestivum) for sustained crop and soil productivity in mollisols of Tarai region

Field experiment was conducted in three consecutive rabi seasons of 200607 to 200809 at the Crop Re- search Centre of G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India to study the effect of site specific NPK recommendation in wheat {Triticum aestivum (L.) emend. Fiori & Paol} for sustained crop and soil productivity in mollisols of Tarai region. The experiment consisted of eight fertilizer combinations comprising of N, P O , and K O. Treatments were T - 170: 60: 120, T - 170: 30: 120, T - 170: 0: 120, T - 170: 30: 2 5 2 1 2 3 4 80, T - 170: 30: 40, T - 170: 30: 0, T - 150: 60: 40 and T - 120: 40: 0, which were laid out in RBD with four replica- 5 6 7 8 tions. Experimental findings revealed that application of N, P O and K O @ 170: 60: 120 kg/ha produced maxi- 2 5 2 mum grain yield, which increased by 7.1% and 16.5 % over recommended NPK (150N: 60 P O : 40 K O kg/ha) 2 5 2 and farmer practice (120 N: 40 P O : 0 K O kg/ha), respectively. Application of nitrogen @ 120 kg N/ha and phos- 2 5 2 phorus @ 40 kg P O /ha as farmer fertilizer practice produced lowest grain yield. Increasing fertilizer nitrogen up to 2 5 170 kg N along with 30 kg P O and 80 kg K O increased the crop growth, yield contributing characters and yield of 2 5 2 wheat significantly. Significant response of P was observed up to 30 kg P O /ha and in case of K up to 80 kg K O/ 2 5 2 ha over no application, whereas further increase in P and K doses had nonsignificant response . However, fertil- ity status of soil after harvest of three cycles of crop increased with increased application of N, P and K upto 170 kg N, 60 kg P O and 120 kg K O/ha. Thus, the results suggests that application of N, P O and K O @ 170, 30 2 5 2 2 5 2 and 80 kg/ha to wheat crop is required for achieving higher productivity on sustainable basis besides maintenance of soil fertility in Tarai region of north India.