tailieunhanh - Crop productivity and soil biological properties influenced by long term application of mineral fertilizers and manures under rice-wheat sequence on mollisols of Northern India

The rice-wheat cropping system, which is considered as the backbone of food selfsufficiency, is facing a sustainability problem due to practices of modern production system with indiscriminate use of chemical fertilizers and pesticides. So, effects of long term use of mineral fertilizers and farmyard manure (FYM) under rice (Oryza sativa)– wheat (Triticum aestivum) cropping system in a Mollisol was investigated. Rice and wheat yields were highest ( and q ha-1 , respectively) with 100% NPK + 15 t FYM ha−1 and lowest in control ( and q ha-1 , respectively). Balanced fertilizers use of (100% NPK + Zn) was also at par with 100% NPK + FYM treatment in rice and wheat yields. The FYM amended treatment gave the highest and significantly more counts of bacteria, fungi and actinomycetes in all four depths of soil (0-15cm, 15-30cm, 30-45cm and 45-60cm) as compared to all other treatments after crop harvest. The observed microbial biomass C with 100% NPK + FYM in four soil depths were (, , and after rice and , , and µg g-1 after wheat, respectively, which was highest and significantly higher over all other treatments. Soil enzymes dehydrogenase, acid and alkaline phosphatase and urease activities were significantly higher with 100% NPK + 15 t FYM ha−1 than all the other treatments. Mineral fertilizer treatments with 100% NPK and 150% NPK were comparable and significantly better than application of 50% NPK, 100% N and 100% NP in different soil biological properties. Application of Zn with 100% NPK increased the crop yields and soil biological properties over 100% NPK. Imbalanced use of mineral fertilizers had the harmful effect on soil biological health. | Crop productivity and soil biological properties influenced by long term application of mineral fertilizers and manures under rice-wheat sequence on mollisols of Northern India