Prediction of post-harvest soil nutrient status through multiple linear regression for targeted yield of hybrid maize

A field experiment was conducted during 2017–18 at Crop Research Centre (CRC), Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, to develop post-harvest soil test values (PHSTVs) and response type of fertilizers with the help of fertilizer prescription equations for achieving targeted yield of hybrid maize following STCR principle. In the present study, the response of hybrid maize to selected four levels of nitrogen (N), phosphorus (P), and potassium (K) and three levels of farm yard manure (FYM) at graded fertility levels was studied. Nutrient requirements (NR) of maize were recorded as 22, 5 and 27 kg/tonnes for N, P, and K, respectively. The contribution of NPK nutrients was observed; from fertilizer (%CF) at 58.2, 62.7, and 420.4%, from soil (%CS) at 33.1, 26.8, and 22.7%, from FYM (% C FYM) at 45.2, 14.4 and 39.4% and from fertilizer with FYM (% IPNM) as 62.4, 63.5 and 427.6%, respectively. Integration of N, P, and K fertilizers with FYM (10 t/ha) resulted in fertilizer savings of 31.2%, 18%, and 16% over NPK alone for a target yield of 4500 kg/ha on soil test values of 150, 35 and 200 kg/ha of KMnO4 -N, Olsen-P and NH4 OAc-K, respectively. The fertilizer response type for phosphorus was “+ - - “. The response of hybrid maize to NPK fertilizers was higher when integrated with FYM as compared to NPK alone. The prediction equations for PHSTVs help in predicting soil test values (STVs) which may save the cost of testing.