基于DSSAT的广西来宾甘蔗水分利用效率指标分析

An Analysis of the Water Use Efficiency Index of Sugarcane in Laibin,Guangxi Based on DSSAT

作物水分利用效率是衡量农业用水科学性与合理性的重要指标,研究甘蔗水分利用效率是实现其高效灌溉管理、提高我国蔗糖业发展的一个关键科学问题。基于SPEI指数,选取典型干旱年,采用DSSAT-Canegro模型开展了不同典型干旱年的甘蔗产量对灌溉制度情景响应机制模拟,根据模拟结果对农田总供水利用效率WUE_(g)、田间水分利用效率WP、真实灌溉水利用效率WUE_(ti)、和灌溉水利用效率WUE_(i)进行评价分析。研究明晰了不同典型干旱年模拟产量的均值随灌溉定额的增加均有较明显的上升趋势,尤其是特旱年;WUE_(g)、WUE_(ti)和WP指标能较好地反映甘蔗产量和水分消耗的关系,三者之间的相关性显著,但WP由于田间蒸散发量的数据不易获取,限制了它在大尺度及长时段的应用。WUE_(i)只反映了甘蔗产量和灌溉量之间的关系,不适用于降水丰富的地区。经分析,推荐WUE_(g)和WUE_(ti)作为广西来宾市甘蔗灌溉用水效率指标。该研究对灌溉用水效率评价和灌溉决策制定具有一定的参考及指导意义。

Crop water use efficiency is an important indicator to measure the scientific and rational nature of agricultural water use,and the study of sugarcane water use efficiency is a key scientific issue to achieve its efficient irrigation management and improve the development of China’s sugarcane industry.In this paper,based on the SPEI index,a typical drought year is selected,and the DSSAT-Canegro model is used to simulate the response mechanism of sugarcane yield to irrigation system scenarios in different typical drought years,Crop water pro⁃ductivity(WP),irrigation water productivity(WUE_(ti)),generalized water use efficiency(WUE_(g))and irrigation water use efficiency(WUE_(i))are evaluated and analyzed based on the simulation results.The study clarifies that the maximum,minimum and mean values of simulated yields in different typical drought years show a significant increasing trend with increasing irrigation quotas;WUE_(g),WUE_(ti),and WP indica⁃tors can better reflect the relationship between sugarcane yield and water consumption,and the correlation between the three is significant,but WP is not easily available due to the data of field evapotranspiration,which limits its application in the large-scale and long period.WUE_(i) reflects only the relationship between sugarcane yield and irrigation and is not applicable to areas with abundant precipitation.After the analysis,WUE_(g)and WUE_(ti)are recommended as sugarcane irrigation water use efficiency indicators in Laibin,Guangxi.The study serves as a reference for irrigation water use efficiency evaluation and irrigation decisionmaking.