Soil test crop response approach for optimizing integrated plant nutrients supply to achieve targeted yield of hybrid maize (Zea mays L.) in Mollisols

A field experiment was conducted during 2017-18 at Crop Research Centre, G.B.P.U.A.&T., Pantnagar with the objective of developing fertilizer adjustment equations and quantifying doses for achieving targeted yield of hybrid maize (Zea mays L.) by using STCR approach. Response of hybrid maize to four levels of N, P and K and two levels of FYM under different fertility levels was studied. Nutrient requirements (NR) were reported as 2.17, 0.46 and 2.74 kg q-1 for N, P and K, respectively. The contribution of nutrients N, P, and K from fertilizers (%CF) was found as 58.2, 62.7 and 420.4% , from soil (%CS) as 33.1, 26.8 and 22.7%, from organic matter FYM (%CFYM) as 45.2, 14.4 and 239.4% , from fertilizer with FYM (%CF*) as 62.4, 63.5 and 427.6%, respectively. Fertilizer adjustment equations and ready reckoners were developed with and without FYM for different targeted yield and soil test values of N, P and K. It was observed that response of hybrid maize to N, P and K fertilizers was higher when integrated with FYM application as compared to N,P and K alone. The average saving of fertilizer by application of 10 tonnes FYM was 24.52 kg ha-1 N, 7.11 kg ha-1 P and 3.50 kg ha-1 K within the range of soil test value and yield targets on Mollisol.