Evaluation of resource and energy utilization, environmental and economic benefits of rice water-saving irrigation technologies in a rice-wheat rotation system

Currently, numerous challenges such as excessive irrigation water consumption, labor shortage, lower economic and environmental benefits pose serious threats to rice cultivation systems. Therefore, more water- and labor-efficient irrigation technologies are needed in rice production for minimal environmental hazards and greater economic benefits. After the screening experiment of water-saving cultivation technologies and cultivars, a two-year field experiment was conducted to further explore the effects of efficient water-saving technologies and rice cultivars on the comprehensive benefits, global warming potential (GWP), grain yield, economic benefits, water productivity, nitrogen partial factor productivity, radiation, accumulated temperature and energy use efficiency (EUE) of a rice-wheat rotation system. Conventional flooding irrigation (F), intermittent irrigation (IR), transplanting rainfed (TR) and rice dry cultivation (D) were implemented with two rice cultivars, including Hanyou73 (HY) and Huanghuazhan (HH). After rice harvest, a winter wheat cultivar (Huamai 2566) was planted with traditional methods. The system of rice dry cultivation and wheat rotation had higher comprehensive benefits, which were attributed to greater water productivity, economic benefits and EUE and lower GWP, especially in the rice growing season. D treatment enhanced the comprehensive and economic benefits by 2.5% and 26.8%, 1.6% and 11.3%, 3.3% and 0.6%, and reduced the GWP by 3.4%, 56.7% and 30.2% compared with F, IR and TR treatments in the rotation system, respectively. During the rice season, D treatment significantly (P < 0.05) increased the economic benefits, water productivity and EUE, but slight decreased the grain yield than other treatments. Overall, rice dry cultivation (especially with the HY cultivar) can achieve higher comprehensive benefits in rice growing season as well as in the whole rotation system.