Impact of Inorganic Fertilizers, Organic Manures, and their Integration on Soil Carbon Sequestration in a Long-term Rice-rice Cropping System

The present study highlights the impact of Inorganic Fertilizers, Organic Manures, and their integration on Soil Carbon Sequestration in a long-term rice-rice cropping system. Large scale changes in land use like deforestation and agricultural activities like biomass burning, ploughing, drainage, low input farming have resulted in significant changes in SOC pools. A field experiment was carried out under field conditions during both kharif and rabi seasons of 2016-2017 and 2017- 2018 at Andhra Pradesh Rice Research Institute and Regional Agricultural Research Station, Maruteru, West Godavari district in the ongoing All India Coordinated Research Project on Long Term Fertilizer Experiment Project. The results reported that the application of 100 % RDF along with ZnSO4 @ 40 kg ha-1 and application of 100 % RDF were not significant. Among different fertilized plots, SOC stocks and carbon sequestration rate in the 15 cm plough layer were significantly higher under 100% RDF + FYM + ZnSO4 (T7) followed by 50 % NPK + 50% N through FYM (T10). At the starting of the experiment in kharif, 1989, the soil organic carbon stock was 11.14 Mg ha-1 and after 29 years of continuous application of organic and inorganic fertilizers, SOC stocks ranged from 11.06 to 24.39 Mg ha-1 at harvest of rabi rice in 2018.