An Appraisal of Various Nutrient Availability Indices of N, P, K and S for Gobhi Sarson (Brassica napus L.) in Ustochrepts of Punjab

A pot experiment was conducted to evaluate different indices of N, P, K and 8 availability for gobhi sarson in Ustochrepts of Punjab. The results showed that crop responded well to the application of both N and P. Nutrient uptake responses were the highest for P followed by N, K and S, respectively. Amongst the various soil test methods employed, organic carbon, Olsen P, 1 M NH₄Ac-K and water soluble 8 were significantly correlated with yield and uptake parameters. Critical levels of soil available N, P, K and S below which the crop may respond to their application were 0.31% O.C., 11.0 mg kg⁻¹ of Olsen P, 56 mg kg⁻¹ of 1 N NH₄OAc-K and 10 109 kg⁻¹ of water soluble S, respectively.