Research on Irrigation Decision-making Method for Salinized Farmland Based on Actual Farmland Water Consumption Monitoring

Abstract: Under the increasing pressure of water scarcity, irrigation decision-making plays a critical role in achieving efficient agricultural water use while maintaining stable and increased crop yields. With the continuous advancement of crop water information sensing technologies, irrigation decisions based on multi-source farmland information monitoring have become an important development direction for precision irrigation. Targeting salinized farmland in arid regions with shallow groundwater tables, this study proposes an irrigation decision-making method based on in situ measured farmland evapotranspiration, which effectively avoids the adverse effects of soil salinity on the measurement accuracy of soil moisture sensors and enables precise irrigation regulation under saline conditions. Based on two consecutive years of comparative irrigation decision experiments conducted on tomato and maize, the results indicate that, compared with conventional soil-moisture-based irrigation decision methods, the proposed approach can reduce irrigation water use by 7.69%–14.29% while increasing crop yield by 19.6%–24.2%, leading to a significant improvement in crop water productivity. Furthermore, under the same decision-making framework, the use of plastic mulching combined with a moderate reduction in irrigation level (irrigation adjustment coefficient reduced from 0.9 to 0.7) further saved approximately 3.6%–9.8% of irrigation water and enhanced water productivity by 4.6%–33.5%. These results confirm the feasibility and advantages of the proposed irrigation decision method for salinized farmland and provide reliable theoretical support and empirical evidence for irrigation management and the development of smart irrigation technologies in arid salinized agricultural regions, with practical significance for advancing precision agriculture.

Keywords: irrigation decision-making; evapotranspiration