Phogat, V.K.Sheoran, Hardeep Singh2018-05-082018-05-082018http://krishikosh.egranth.ac.in/handle/1/5810044903Organic agricultural systems aim at reducing the use of synthetic fertilizers and pesticides in order to improve soil quality and food safety. Despite the integral role of the management practices in agricultural production, there is a limited understanding of the effects of organic farming system on soil properties for seeking as an alternative to the conventional practices. The impact of organic farming on soil quality in terms of changes in various soil properties as compared to conventional farming was evaluated. Surface soil samples were collected from organic farm under different cropping systems visa- vis agricultural and horticultural cropping systems and their adjoining conventional farms from 25 different locations in 11 districts of Haryana. The texture of soils at different locations varied between sand to clay loam, representing almost all the soil types of the state. The soil samples were analyzed for various soil physical, chemical and biological properties. Organic farming system decreased the bulk density of soils at majority of the locations. The average bulk density values of all the locations reduced significantly from 1.47 to 1.45 Mg m-3 under organic as compared to conventional farming system. The water stable aggregates (>0.25 mm), moisture content at field capacity and plant available water were found to increase. Shifting from conventional to organic farming had no effect on pH and EC but reduced the CaCO3 significantly.Organic farming significantly increased the SOC from 51% to 62% as a result of which the SCS increased from 11.17 to 13.29 Mg ha-1 over conventional farming. The magnitude of increase in LOC, POC and MOC was 48.9, 23.6 and 14.7 %, respectively. Different organic carbon pools in various fractions followed the order MOC > POC > LOC. In addition, an increase in macro and micro nutrients was also observed. The total bacterial, fungal and actinomycetes counts were increased by 56.9, 55.2 and 49.5%, respectively, than those in the conventionally managed soils. Overall, population of rhizobium, azotobacter, azospirillum and PSB increased significantly by 44.1, 39.0, 47.1 and 43.5%. Under organic farming, dehydrogenase activity, alkaline phosphatase activity and MBC increased by 57.5, 22.8 and 69.1 %, respectively, as compared to conventional farming system. It is concluded that the conversion of land from conventional to organic farming is good for maintaining soil quality and could be adopted or promoted as an alternative to the conventional farming practices for sustainable use of natural resources, and food safety coupled with climate change.enThesis