Effects Of Bentonite On The Yield And Medicinal Composition Of A.Membranaceus Var.Mongholicus In Saline-alkali Land

This experiment selected bentonite as a soil conditioner,a one-time application into the saline land,the collection of Mongolian astragalus and saline soil samples,the determination of Mongolian astragalus morphological indicators,photosynthetic indicators,physiological indicators,yield,potency components and soil physical and chemical properties,to explore the impact of bentonite on the yield and potency components of Mongolian astragalus and saline land,for the cultivation of Mongolian astragalus in saline land and saline land improvement to provide a new theoretical basis and specific technical measures.The experimental results showed that.1.The growth of morphological indices of Astragalus Mongolica was promoted by saline-alkali application,and the plant height,stem thickness,root length,root surface area and root fresh weight of the T5 treatment were significantly higher than those of the CK treatment,and the root thickness,root volume and root dry weight of the T6 treatment were significantly higher than those of the CK treatment.2.The relative content of chlorophyll and stomatal conductivity of T5 treatment after saline alkali application to bentonite were significantly higher than those in CK treatment.The transpiration rate,net photosynthetic rate and chlorophyll fluorescence parameters of Astragalus Mongolica in the T6 treatment were significantly improved compared with the CK treatment,the leaf water efficiency was not significantly improved compared with the CK treatment,and the intercellular carbon dioxide concentration in the T6 treatment was significantly lower than that in the CK treatment.3.Superoxide dismutase,peroxidase,catalase,soluble sugar and soluble proline of Mongolian astragalus treated with T6 after saline-alkali application of bentonite were significantly improved compared with CK treatment,the soluble protein of T5 treatment was significantly improved compared with CK treatment,and the malondialdehyde treatment of T6 treatment was significantly lower than that of CK treatment.4.The application of suitable amount of bentonite to saline soil had significant effects on both yield and potent components of Astragalus mongolianus.The highest yield of Astragalus mongolianus was T5 treatment with 6766.0 kg hm^-2,followed by T6 treatment with 6709.5 kg hm^-2,with no significant difference between the two treatments.The highest content of the medicinal components,astragaloside and mauroisoflavone glucoside,reached0.132%and 0.050%,respectively,in the T4 treatment,followed by the T6 treatment,with no significant difference between the two treatments.5.After the saline alkaline soil was applied to bentonite,the soil environment and soil chemical properties of each soil layer were effectively improved.The soil moisture content and soil organic matter of the 0-40 cm soil layer of the T6 treatment significantly increased the soil moisture content and soil organic matter,and the soil bulk density,soil compactness,soil p H and soil total salinity were significantly reduced compared with the CK treatment.6.This study showed that appropriate bentonite application rate could improve the yield and content of medicinal components of Astragalus mongolianus and improve the saline soil environment.Through the analysis of yield and potent components and economic benefits of Astragalus mongolianus,the comprehensive analysis concluded that the best bentonite application rate of T5 treatment（1800 kg-hm-2）can have the highest yield and economic benefits based on ensuring the potent components and improving the saline soil.