Phogat, V.K.Lamba, Shubham2018-10-172018-10-172018http://krishikosh.egranth.ac.in/handle/1/5810081688Maintenance of carbon stocks in agricultural soils to an optimum level is crucial for achieving food security and environmental quality. Carbon is continuously cycling between diverse global carbon pools, understanding the dynamics of soil organic carbon and its relation with farming practices is utmost important for management of soil organic carbon pools and sustainability in agricultural production systems. The availability of nutrients and organic carbon in soils of Haryana is depleted primarily because of exhaustive crops, chemical fertilizers, and poor management followed by less or no application of manures and organic amendments. Soils of Haryana have potential to sequester carbon in varying amounts depending upon the soil texture and cropping system adopted. Samples from the surface and sub-surface soils were collected with the help of handheld GPS from Sonepat, Panipat, Karnal, Kurukshetra, Ambala, Yamunanagar, Panchkula, Jind, Kaithal, Rohtak, Jhajjar, Faridabad, Mewat, Palwal and Gurugram districts. The soil organic carbon (SOC) (3.53 g kg-1), soil organic carbon stock (SCS) (8.81 Mg ha-1 C) and carbon sequestration rate (0.88 Mg ha-1 C) were significantly higher under rice-wheat cropping system as compared to rest of the cropping systems. Likewise, the Microbial biomass carbon (MBC) (54.33 mg kg-1), light fraction carbon (LFC) (0.32 g kg-1), heavy fraction carbon (HFC) (0.98 g kg-1), coarse particulate organic carbon (cPOC) (0.26 g kg-1), fine particulate organic carbon (fPOC) (0.37 g kg-1), mineral-associated organic carbon (MAOC) (1.29 g kg-1) and dehydrogenase activity (DH) (5.878 μgTPF/g soil/24 h) were also significantly higher under rice-wheat cropping system. At various soil profile depths, the SOC (4.73 g kg-1), SCS (9.94 Mg ha-1 C), SCR (0.99 Mg ha-1 C), and carbon pools such as MBC (112.86 mg kg-1), LFC (0.43 g kg-1), HFC (1.38 g kg-1), cPOC (0.37 g kg-1), fPOC (0.49 g kg-1) and MAOC (1.96 g kg-1) were found significantly higher at surface 0-15 cm depth as compare to sub-surface soil depths. Nitrogen (217 kg ha-1), phosphorus (19.4 kg ha1), potassium (219 kg ha-1) were found significantly higher at the surface (0-15 cm) of rice-wheat cropping system. Among DTPA extractable micronutrients zinc (0.712 mg kg-1) was found significantly higher in cultivated fields of rice-wheat cropping systems whereas copper was found higher in cultivated fields of all cropping systems with significant differences. Higher values of bulk density (BD), pH and EC were observed in pearl millet-based cropping systems dominated by loamy sand texture. The relationship of SOC, SCS, SOC pools and different physicochemical properties showed both positive and negative correlation with the varying level of significance. The pH and EC were found most non-significant parameters when correlated with SOC, SCS, SOC pools and nutrients. The soils of the state have significantly lost SOC from cultivated fields and thus bears significant potential for carbon sequestration whereas rice-wheat cropping system is nearly saturated and possess very less or no potential to sequester carbon.enThesis