Integrated Evaluation of the Water Deficit Irrigation Scheme of Indigowoad Root under Mulched Drip Irrigation in Arid Regions of Northwest China Based on the Improved TOPSIS Method

Limited water resources and low productivity limit the sustainable development of agriculture in northwest China. In this study, drip irrigation under plastic film was used to achieve an optimal deficit (WDI) scheme for cultivation indigowoad root (Isatis tinctoria L.). Field control experiments were conducted 2016 2017. Evaluation WDI schemes carried out by considering five indices: consumption, yield, use efficiency (WUE), indigo, (R,S)-goitrin. To enhance reliability results, analytic hierarchy process (AHP) entropy weight method (EWM) adopted calculate combined evaluation index. Finally, improved technique order preference similarity ideal solution (TOPSIS) that integrated AHP–EWM weights construct a unified, comprehensive model mulched would produce high yield while saving water. The results indicated mild WD (specifically, V1G1 treatment) continuously exerted during vegetative fleshy growth periods, which enhanced WUE quality certain extent without significantly reducing yield. These provide scientific basis China other areas with similar environment.