[Effects of natural organic soil amendments on quality of Panax notoginseng]

The effects of four natural organic soil amendments on the quality and pesticide residues of Panax notoginseng were investigated through field experiments and the suitable dosage ratio of each soil amendment was selected to provide a new idea for the pollution-free cultivation of P. notoginseng. The four natural organic soil amendments used in this study were Jishibao, Jihuo, Fudujing, and omnipotent nutrients, which were produced by mixed fermentation of aboveground parts of different plants, biological waste residue, and biochar. During the experiments, only four soil amendments were applied to P. notoginseng instead of any pesticides and fertilizers. The experiment was designed as four factors and three levels. There were three dosage gradients(low, medium, and high) for Jishibao(A), Jihuo(B), Fudujing(C), and omnipotent nutrients(D). When the dosage of one soil amendment changed, the do-sage of the other soil amendments remained medium. There were 10 groups in addition to the soil amendment-free group as control(CK). The results showed that the four soil amendments could significantly improve the growth environment of P. notoginseng and increase the seedling survival rate and saponin content of P. notoginseng. The seedling survival rates of the treatment groups increased by 8.24%-30.05% as compared with the control group. Furthermore, the content of pesticide residues in P. notoginseng was too low to be detected, and that of heavy metals in P. notoginseng was far lower than the specified content in the Chinese Pharmacopoeia(2020). The optimal effect was achieved at medium dosage for all the soil amendments with the highest content of saponins, high seedling survival rate, and significantly reduced heavy metals, such as lead, cadmium, arsenic, and mercury.