Rice Genomics and Genetics 2025, Vol.16, No.5, 254-259 http://cropscipublisher.com/index.php/rgg 256 yield (Ishfaq et al., 2020; Martínez-Eixarch et al., 2021). This makes AWD a viable option for sustainable rice cultivation in Jiangsu, where water resources are limited. 3.2 Guanghan, Sichuan—AWD ecological benefits in a double rice cropping system In Guanghan, Sichuan, the implementation of AWD in a double rice cropping system has highlighted several ecological benefits. The technique not only conserves water but also reduces methane emissions, a significant contributor to greenhouse gases from rice fields (Malumpong et al., 2020; Martínez-Eixarch et al., 2021). The reduction in methane emissions is particularly important in addressing climate change impacts. Additionally, AWD has been shown to improve water productivity, making it an eco-friendly alternative to continuous flooding (Patikorn et al., 2018; Ishfaq et al., 2020). These ecological benefits make AWD a suitable irrigation strategy for the double rice cropping systems prevalent in Sichuan. 3.3 Comparative insights and practical implications Comparing the application of AWD in Xinghua and Guanghan reveals several insights. Both regions benefit from reduced water usage and improved water productivity, which are crucial in areas facing water scarcity (Patikorn et al., 2018; Wijesundara, 2024). However, the ecological benefits, such as reduced methane emissions, are more pronounced in Guanghan due to the double cropping system (Malumpong et al., 2020). Practically, the adoption of AWD requires careful management to ensure water levels are maintained appropriately, as variations can impact yield and environmental benefits (Martínez-Eixarch et al., 2021; Duong et al., 2024). The successful implementation of AWD in these regions underscores its potential as a sustainable irrigation practice that balances water conservation with agricultural productivity. 4 Effects on Water Use and Irrigation Efficiency 4.1 Change in total irrigation volume Alternate wetting and drying (AWD) irrigation significantly reduces the total volume of water used in rice cultivation compared to continuous flooding (CF). Studies have shown that AWD can decrease irrigation water usage by approximately 33.88% globally, highlighting its potential as a water-saving technique (Gao et al., 2024). In Nepal, AWD plots received 57% less irrigation water than CF plots without a significant difference in yield, indicating a substantial reduction in water use (Howell et al., 2015). Similarly, in Italy, AWD was found to require less water from June onwards compared to continuous flooding, while still maintaining groundwater recharge (Gilardi et al., 2023). 4.2 Field seepage and evaporation comparisons AWD irrigation affects field seepage and evaporation differently than continuous flooding. In the Mid-South United States, AWD did not result in decreased gross primary production (GPP), evapotranspiration (ET), or transpiration (T), suggesting that the periodic drying associated with AWD does not negatively impact these processes (Reavis et al., 2024). This indicates that AWD can maintain similar levels of field seepage and evaporation as CF, while using less water overall. 4.3 Improvement in water use efficiency (WUE) AWD irrigation has been shown to improve water use efficiency (WUE) in rice cultivation. In China, AWD increased WUE by 25.3% to 28.9% across different rice cultivars, primarily due to enhanced root and shoot growth and development (Chu et al., 2016). A global meta-analysis also reported that AWD enhances WUE by 20.27% and irrigation water use efficiency by 47.58% (Gao et al., 2024). In Bangladesh, AWD treatments demonstrated higher WUE compared to continuous flooding, with treatment T1 achieving a WUE of 41.86 kg/ha/cm, compared to 38.64 kg/ha/cm for the control. 5 Impact on Rice Growth and Yield 5.1 Tiller number and plant height trends Alternate wetting and drying (AWD) irrigation has shown varied effects on tiller number and plant height in rice cultivation. In a study conducted in Nepal, it was observed that tillering was significantly higher under AWD compared to continuous flooding (CF), although leaf elongation rates did not differ between treatments (Howell et
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