Integrated rice-crab co-culture system shows capability to reduce greenhouse gases emission and global warming potential

Rice plays an important role in feeding the world population, but despite that it brings environmental problems associated with greenhouse gases (GHG) emissions. The rice-crab co-culture (RC) system is environmentally friendly, with improved rice and farm production. Despite all this, study gaps exist to identify the response of GHG emissions and global warming impact (GWI) with the RC system. Two experiments were conducted to elucidate the RC system's influence on said aspects. The first experiment consisted of four treatments: ricemonoculture (RM), 3000 crabs wha(-1) without feed (RC3000), 6000 crabs ha(-1) with feed (RC6000), and 12,000 crabs ha(-1) with feed (RC12000). The results expressed that cumulative emission for N2O was reduced by 74.4 % in RC3000, followed by 71.7 % in RC6000, and 59.2 % in RC12000, while the CH4 emissions were reduced in RC6000 (42.4 %) and RC12000 (62.1 %) as compared to the RM, respectively. Compared with RM, GWI was significantly reduced to 12.4, 45.1, and 61.8 %, respectively, in RC3000, RC6000, and RC12000. For NH3 volatilization, the results achieved herein indicated that RC3000 and RC6000 reduced the emissions significantly compared with the other treatments. The tested treatments in the second micro-plot experiment were: flooded rice monoculture (RM-F), alternate wetting-drying rice monoculture (RM-D), and rice-crab co-culture (RC). The results showed that cumulative N2O emission was reduced significantly with RM-D (8.7 %) and RC (23.9 %), and the CH4 emission was reduced in RM-D (35.4 %) and RC (13.5 %) compared with RM-F. In addition, the GWI was significantly reduced with RM-D (34.9 %) and RC (13.7 %), respectively. The crab's movement in the field enhances the aerobic condition to reduce the emissions, also eating of phytoplankton disturbs the emission pathways to reduce GHG losses. Promoting this system will achieve sustainable intensification and multiple economic benefits for the farming community depending on the success of co-culture systems in different countries. The current study provides more insights into global warming control due to rice cultivation. It suggests using the RC system will reduce GHG emissions and associated problems. The difference among their emission suggests that RC system gaseous emission largely depends on soil fertility status.