Assessing the efficacy of water management and wheat straw addition in mitigating methane emissions from rice paddy fields

To improve the quality of soil, agriculture typically uses organic additions like wheat straw (WS). Water management (WM) methods such as alternative wetness and dryness irrigation (AWDI) in paddy rice farming can increase water use efficiency and reduce greenhouse gas (GHG) emissions. In this study, a randomized complete block design (RCBD) pot greenhouse experiment was conducted to assess the effects of WM (CFI (continued flooding irrigation) and AWDI), WS (15.0 and 30.0 ton ha(-1)), and their interaction (WS*WM) on CH4 emissions and rice yield in a paddy calcareous soil cultivated with rice. The largest CH4 emission occurred 30 and 70 days following rice planting. Single applications of WS at 15.0 and 30.0 ton ha(-1) significantly increased CH4 emissions by 19.60% and 68.70% (P < 0.01), respectively, compared to the Control. Compared to CFI, the AWDI reduced CH4 emissions by 31.20% (P < 0.01). The correlations between AWDI and CH4 emissions in days after rice planting were significantly negative at the 0.01 level based on Pearson correlation. Adding WS in the AWDI significantly decreased CH4 emissions by 27.70 and 25.64% in 15.0 and 30.0 ton ha(-1) added WS (P < 0.05), respectively, compared to sole WS. Both rates of WS resulted in a considerable increase in biomass and rice grain compared to the Control, while the AWDI had no significant effect on biomass and grain yield. Our data showed significant interaction between AWDI and WS on biomass. Our study shows that the AWDI saved 18.50% water compared to the CFI.