Field Crop 2025, Vol.8, No.3, 154-165 http://cropscipublisher.com/index.php/fc 159 5.2 Water resource utilization efficiency and water-saving potential The greatest advantage of AWD is actually water conservation, which is particularly useful in alleviating the pressure on water resources caused by rice cultivation. The traditional rice fields have been flooded all along, and a lot of water has actually seeped or evaporated, which is quite a waste. AWD reduces unnecessary water accumulation in the fields, allowing more water to be truly used for crop transpiration. This means maintaining yields with less water and sometimes even allowing for more grain production. Research shows that AWD can generally save 15% to 30% of irrigation water, and in some areas, it even exceeds 40%, and water use efficiency is also increased by 10% to 30% (Rejesus et al., 2011). Especially in areas that frequently suffer from water shortages, AWD can also reduce the frequency of water pumping, and electricity and fuel costs can be saved by 20% to 30% (Husain et al., 2010). This directly means cost reduction and income increase for farmers. From a broader perspective, due to the reduced water consumption per unit area, the same amount of water can irrigate more fields, and the overall grain output can also increase. At the same time, it can alleviate the over-exploitation of groundwater and save energy for pumping water. Therefore, AWD not only performs well in farmers' fields but also plays a role in water resource allocation throughout the region. It can be regarded as an effective approach to addressing water shortages and promoting sustainable agricultural development. 5.3 Role in biodiversity and ecosystem services Rice fields are actually quite unique. They are not only farmlands but also have the characteristics of wetlands, and their ecological functions change with the way water is managed. The AWD, which alternates between dry and wet irrigation, alters the hydrological conditions in the fields through periodic drying, exerting considerable influence on animals, plants and ecological services. When the water keeps flooding, the fields are more like wetlands, suitable for living creatures such as apple snails and aquatic insects-some of which are pests and some are beneficial. However, AWD will break this aquatic environment, reducing snail damage and some weeds, and at the same time making it easier for some terrestrial natural enemies to enter the fields to catch pests. As a result, the effect of ecological pest control is enhanced (Chapagain et al., 2011). The fields being dry and wet can also reduce fungal diseases like rice blast and inhibit the reproduction of rice planthoppers, but it may also make field mice more active. For soil microorganisms, AWD enhances the diversity of aerobic bacteria and nitrifying and denitrifying bacteria, making the nitrogen cycle more active. At the same time, methanogens are less active, which is helpful for emission reduction (Brito et al., 2021). As for carbon sinks, the situation is a bit more complicated: AWD may accelerate the decomposition of organic matter, but if combined with straw returning to the field, it can actually increase net carbon sinks. Overall, while AWD saves water and reduces emissions, it also improves some ecological functions. However, it is necessary to pay attention to the possible problems it may bring and try to balance production and ecology through optimized operation. 6 Considerations at the Social, Economic and Policy Levels 6.1 Economic benefit analysis of AWD When it comes to promoting agricultural emission reduction technologies, whether they are economically feasible is actually very crucial. The greatest advantage of the AWD field management approach is that it can save money and even earn more. It directly reduces the cost of oil, electricity or water by cutting down on irrigation water and the frequency of pumping. In some places, it can save several hundred yuan per hectare. Moreover, the output was basically not affected. Sometimes, the harvest was even slightly higher, truly achieving "saving money without reducing production" (Suwanmaneepong et al., 2023). As a result, the actual income of farmers increased instead. There are also some less obvious benefits, such as fewer pests and diseases and less money on pesticides. The root system grows better and there are fewer cases of lodging. In the long run, AWD can alleviate the problem of over-exploitation of groundwater and is beneficial to the sustainable development of agriculture. If it is a larger farm, more land can be cultivated with the same amount of water, and the potential income will be even more considerable (Uddin et al., 2020). Although using AWD requires more effort in field patrol and management, it is still more convenient overall. Many farmers, seeing that it can indeed save money without affecting the harvest, are willing to follow suit and use it. As a result, the promotion of AWD becomes much easier, laying a good foundation for its wide application.
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