Abstract:

This study explored the nutrient requirements of Lycium barbarum in Ningxia using a 4-year-old “Ningqi No. 7.” Four treatments (150 mg·L^-1, 210 mg·L^-1, 270 mg·L^-1, and 350 mg·L^-1) were set up using nitrogen concentration as the control index based on an experimental device for nutrient recycling in soilless cultivation. The growth, yield, and quality indexes of L. barbarum were monitored, and nutrient absorption during growth was examined. The results showed that the absorption of large and medium elements (N>K>Ca>Mg>P) as well as trace elements (Fe>B>Mn>Zn>Cu). Maximum N and K absorption was 1.578 g·d^-1 and 0.954 g·d^-1 at the spring shoot growth stage, 0.029 g·d^-1, 9.321 mg·d^-1, and 3.935 mg·d^-1 at the first flowering stage, and 0.254 g·d^-1, 0.764 g·d^-1, 1.113 mg·d^-1, 0.498 mg·d^-1, and 0.184 mg·d^-1 at the summer fruit stage. N, P, and K uptake had correlation coefficients of 0.95, 0.98, and 0.84 with yield, respectively, and none significant for the trace elements. The TOPSIS entropy weight analysis identified the T4 treatment (350 mg·d^-1) as optimal. Producing 1000 kg of dried wolfberry fruit required the absorption of 269.92 kg of N, 5.96 kg of P, 133.93 kg of K, 135.73 kg of Ca, 48.81 kg of Mg, 534.04 g of Mn, 1729.08 g of Fe, 96.79 g of Zn, 41.08 g of Cu, and 737.49 g of B, with nutrient utilization ratios of N:P:K:Ca:Mg=10:0.22:4.96:5.03:1.81 (major elements) and Fe:Mn:Zn:Cu:B=10:3.09:0.56:0.24:4.27 (trace elements).

Key words: Lycium barbarum, nutrient absorption, nutrient use characteristics, entropy weight TOPSIS method, Ningxia