Long-term Effects of Zinc, FYM, and their Combination on Soil Chemical Properties in Rice-based Cropping Systems

This study examines the long-term effects of zinc (Zn), farmyard manure (FYM), and their combination with NPK fertilizers on soil chemical quality in rice-based cropping systems (RBCS) on calcareous soils in Northern Bihar.Initiated in Kharif 1985 at RPCAU Experimental Farm, Pusa Bihar, the experiment involved four fertility levels (control, 50%, 100%, and 150% recommended dose of fertilizers, RDF) and six replications in a randomized block design (RBD).Two cropping systems were tested: Rice-Wheat-Sorghum (R-W-S) and Rice-Mustard-Moong (R-M-M).Recommended NPK doses were 120:60:40 for rice and wheat, 60:50:30 for mustard and sorghum, and 20:50:30 for moong.After ten cropping cycles, zinc deficiency was noted in treatments with 150% RDF.Thus, Zn and FYM amendments were superimposed on four replications, leaving two untreated.Superimposed treatments included application of 10 kg Zn/ha, 10 kg Zn/ha + 5 t FYM/ha, 10 t FYM/ha, and 10 kg Zn/ha + 10 t FYM/ha, applied in alternate years.Using paired t-test for analysis, soil chemical parameters were assessed in the 36 th crop cycle after the 106 th rice harvest in 2020.The combination of 10 kg Zn/ha and 10 t FYM/ha significantly improved soil chemical parameters, including organic carbon and available N, P, K, S, Zn, Cu, Fe, Mn, and B, while soil pH and EC remained unchanged.The study concludes that integrated use of NPK fertilizers with FYM enhances soil quality in long-term RBCS, with 10 kg Zn/ha crucial for maintaining Zn balance in calcareous soils. HIgHLIgHtSm It was a long-term experiment, after 10 th cycle of cropping, superimposition treatments applied over the replication of initial treatments m We have taken the soil samples after the harvest of only rice cop from both the cropping sequences m The integration of NPK fertilizers with FYM proved to be beneficial with regards to soil quality and health.m Integration nutrition management strategy is viable approach to restore soil chemical attributes.m The micronutrients deficient calcareous soil particularly Zn, can be optimize with the use of Zn fertilizer sources integration with FYM.