Shri RamVineet Kumar2020-02-292020-02-292019-08http://krishikosh.egranth.ac.in/handle/1/5810143988A Study was conducted during 2016-17 to assess the soil quality and relationship between soil quality indices with crop productivity in an ongoing long term fertilizer experiment at Norman. E. Borlaug Crop Research Centre, G. B. Pant University of Agriculture and Technology, Pantnagar. To achieve the objectives of the study soil samples were collected from each plot from 0-15, 15-30, 30-45 and 45-60 cm depth after harvesting of rice and wheat crops and were analyzed for soil physico-chemical and biological properties. Results showed that continuous application of 100% NPK in combination with FYM@ 15 t ha-1 gave highest grain yield of rice (51.87 q ha-1) and wheat (48.60 q ha-1) which was significantly higher than all other fertilizer treatments. The soil organic carbon declined in control up to one third (0.62 per cent) from initial organic carbon (1.48%), whereas combined use of NPK fertilizers and FYM restored its initial status. Availability of all macro and micro nutrients was decreased with the increase in soil depths. Avoiding P, K and Zn application with continuous cropping, drastically reduced their availability in soil in both surface and subsurface soil. Physical properties of soil viz. BD, WHC, SHC and MWD were also improved with integrated nutrient management system. Soil biological properties were better under 100% NPK+FYM @ 15 t ha-1 compared to alone mineral fertilizer application and control. Highest soil dehydrogenase enzyme activity (353.61 and 365.22 μg TPF 24 h-1 g-1 soil) was observed in FYM amended treatment followed by balanced application of fertilizers (312.64 and 327.02 22 μg TPF 24 h-1 g-1 soil) after rice and wheat harvest, respectively. Physical, Chemical and Biological indices and soil quality after rice and wheat harvest with balanced and imbalanced alone mineral fertilizer or with FYM was significantly correlated with each other as well as productivity of rice and wheat crops. Available Zn content showed significant regression coefficient for contribution in improving the yields of both rice and wheat. A good soil quality index values were observed under 100% NPK+FYM and balanced application of fertilizer treatments (100% NPK+Zn). Continuous increase in minimum temperature and decrease in bright sunshine hours believed to decrease rice and wheat grain yield. Similarly SOC, available NPK decreased and bacterial population in soil increased by all fertilizer treatments as compared to control. The results indicated that integrated use of chemical fertilizer along with FYM and balanced use of fertilizer nutrients for rice-wheat cropping on a Mollisols is a sustainable nutrients management practice to the farmers.enThesis