Combined effects of rain-shelter cultivation and deficit micro-sprinkler irrigation practice on yield, nutrient uptake, economic benefit and water productivity of Panax notoginseng in a semi-arid region of China

The excessive rainfall and irrigation amount in the facility herbal medicine production system (FHmPS) in China leading to a severe root rot disease of Panax notoginseng, which endangers root yield and quality, compromise economic profit and waste resources. Therefore, the objective of our research was to seek optimal irrigation and cultivation management strategy for FHmPS to improve Panax notoginseng production and economic benefit. A three-year (2019, 2020 and 2021) field experiment was conducted on Panax notoginseng under two shelter-cultivation [rain-shelter cultivation (Sr) and unrain-shelter cultivation (NSr)] at three deficit irrigation levels [I1= 65%W, I2= 75%W, I3= 85% W, where W was the irrigation quota when the upper and lower limits of irrigation are (100% ∼ 40%)θFC under shelter-cultivation] to explore the combined practices effects on yield, quality, economic benefit, water productivity (WP) and nutrients uptake of Panax notoginseng, and to obtain the optimal irrigation and cultivation supply practice by the technique for order preference by similarity to ideal solution (TOPSIS). The results showed that SrI2 obtained relatively high plant nutrient uptake, net profit, WP, and quality. SrI2 significantly decreased the root rot incidence by 6–17.5% in comparison to other treatments. However, compared with rain-shelter cultivation, unrain-shelter cultivation weaken these effects in Panax notoginseng. Deficit irrigation promoted Sr to obtain higher WP than NSr. According to the result of TOPSIS, the comprehensive ranking of SrI2 and SrI3 were first and second among the practices, regardless of growing seasons and planting years. The SrI2 significantly decreased the yield of Panax notoginseng by 5.4%− 20.8% in comparison to other treatments. SrI2 and SrI3 were highly recommended for facility herbal medicine production system (FHmPS) in the semi-arid area of Southwest China.