Abstract:

In order to solve the problem of efficient utilization of water resources in film−mulched drip irrigation cotton fields under film in the arid areas of Xinjiang,this study integrated the yield of 123 groups of seed cotton and66 groups of irrigation water use efficiency (IWUE)data from 40 Chinese and English literatures from 2000 to 2023, quantified the deficit irrigation effect by Meta−analysis,and combined with the entropy weighted−TOPSIS method to construct a multi−objective optimization model including yield,IWUE and economic benefits.In order to reveal the differences in the effects of irrigation quota on yield,IWUE and economic benefits in the cotton areas in southern and northern Xinjiang,the optimal irrigation quota were screened.The results showed that from 2000 to 2023,the average cotton yield of fully irrigated (3897m^³·ha⁻¹)and deficit irrigation (2928m^³·ha⁻¹)in the cotton area of southern Xinjiang was 5272kg·ha⁻¹ and 4723kg·ha⁻¹,respectively.The IWUE was 1.30kg·m⁻³ and 1.49kg·m⁻³, respectively,and the average cotton yields of fully irrigated (4018m³·ha⁻¹)and deficit irrigated (2950m³·ha⁻¹)in northern Xinjiang were 5487 kg·ha⁻¹ and 4241 kg·ha⁻¹,respectively,and the IWUE was 1.39kg·m⁻³ and 1.56kg·m⁻³, 

respectively.The cotton yield in southern Xinjiang and northern Xinjiang decreased by 11.04%(P<0.01)and 25.38%(P<0.01),respectively,while IWUE significantly increased by 16.23%(P<0.05)and 12.33%(P<0.05).Based on the entropy weight−TOPSIS method,the recommended irrigation quota is 3150m^³·ha⁻¹ in the cotton area of southern Xinjiang and 3071m^³·ha⁻¹ in the cotton area of northern Xinjiang,both of which were the optimal solutions for the comprehensive benefits of water saving,stable yield,economic benefits and ecological security.

Key words:

Drip irrigation under the membrane, Deficit irrigation, Irrigation water use efficiency, Regional differences, Meta?analysis, TOPSIS