Screening and effect analysis of soil amendments for understory cultivation of polygonatum kingianum based on entropy-weighted TOPSIS

Abstract

To identify suitable soil amendments for the understory cultivation of Polygonatum kingianum and to address issues such as soil acidification, nutrient imbalance, and exacerbated soil-borne diseases resulting from continuous cropping of preceding Panax notoginseng, this study utilized two-year-old P. kingianum seedlings as experimental material. Three soil amendments—quicklime, wood ash, and tetramycinwere applied at three different concentration levels. After one year of planting, the yield, quality, and soil physicochemical properties of P. kingianum were measured to evaluate the effects of these amendments on agronomic traits, nutrient accumulation, and soil ecological and physicochemical characteristics. The results demonstrated that all tested amendments improved seedling survival rates and reduced the incidence of root rot in P. kingianum. All treatments effectively reduced the incidence of root rot in Polygonatum kingianum, with wood ash showing the greatest reduction (60%–80%), followed by quicklime (48%–72%) and tetramycin (58%–68%). A comprehensive evaluation using the entropy-weighted TOPSIS method indicated that all amendment treatments outperformed the untreated control group (CK). Among them, the wood ash C3 treatment (1200 kg hm-²) was the most effective, increasing yield by 51.96% compared to CK.