Integrated Effect of Organic and Inorganic Manuring on Crop Yield and Soil Nutrient Balance in the On-going Century-old Permanent Manurial Experiment

Aim: The present study reports the results of continuous application of different rates of N, P and K and organic manure to a Maize-Sunflower cropping system on the changes in soil available nutrients status after harvest of 172th crop of maize.

Materials and Methods: We studied the long-term effect of organic and inorganic manuring on crop yield and soil nutrient management under Maize–Sunflower cropping system in 112 years old Permanent Manurial Experiment Field. Significant build-up in soil fertility in terms of alkaline KMnO4-N, Olsen-P, NH4OAc-K, K2Cr2O7–C and CaCl2-S as well as DTPA-Fe, Mn, Cu, Zn were assessed under eight treatments consist of Unfertilized Control, NP, NP, NPK (Chemical Fertilizer Alone), FYM (N Equivalent Basis), FYM (Every Year), Poultry Manure and NPK+FYM.

ResultS and Discussion: Recorded data from 2008 shows that continuous application as 100%NPK+FYM @12.5 t ha-1 achieved highest grain yield (hybrid maize CO 6), soil organic carbon, available nitrogen, available potassium, available sulphur and micronutrients content. Highest P recorded in poultry manure on nitrogen equivalent basis than INM irrespective of the crops. Inorganic fertilizer application alone resulted in a pH of >8.0, whereas fertilizer and manure application as well as manure application alone resulted in a pH of < 8.0 in soil. The increase in available S in INM, NPK alone might be due to single super phosphate (SSP) and FYM which contained about 12 and 0.74 % of S, respectively. Thus, considering soil-quality conservation and crop yield, 112 years of study indicated that combined application of NPK and organic manure is a better nutrient-management option in this irrigated maize sunflower cropping system.

Conclusion: These results conclude that for better crop yield and soil quality, integrated usage of organic and inorganic nutrient should be advocated in the Maize-Sunflower cropping system under Alfisol.