Effect of organic rice (Oryza sativa) cultivation on greenhouse gas emission

Organic cultivation of crops is important for improving and maintaining soil health and reducing environmental pollution. The organic sources of fertilizer also have impact on emission of greenhouse gases. A field experiment was conducted during 2015-16 and 2016-17 in organic rice (Oryza sativa L.) field to study the impact of organic farming on Global Warming Potential (GWP).Treatments consisted of eight combinations namely: (T1) non-amended control; (T2) Recommended dose of fertilizers; (T3) FYM; (T4) VC; (T5) FYM + CR; (T6) VC+CR; (T7) FYM + CR + B; and (T8) VC+CR+B. Experimental results revealed that Global Warming Potential (GWP) of various treatments varied from 569.95 kg to 1840.55 kg CO2 eq. ha-1 and 634.66 kg to 1899.20 kg CO2 eq. ha-1 during both years, respectively. Different organic treatment combinations led to about 3.0 to 29.4%reduction in GWP over the conventional system, while 67.78%reduction was observed in control.The order of GWP among different combination of treatments was as follows: Control < VC < FYM < FYM+CR < VC+CR < VC+CR+B < FYM+CR+B < Conventional. This study indicated that replacement of existing conventional systems with various organic practices could reduce GWP of the system and thus needs to be considered for development of sustainable farming systems.