Improvement Of Astragalus Continuous Crop Soil And The Effect On Soil Microbial Community By Reductive Soil Disinfestation

Astragalus membranaceus,leguminous Astragalus genus herb,is a widely used traditional Chinese medicinal material.The increase in market demand has led to the deepening of continuous cropping,and soil-borne diseases such as root rot have increased year by year.Reductive Soil Disinfestation(RSD),an emerging method for soil remediation,is green,easy to obtain materials,and efficient,but there is a lack of relevant research reports in Northwest China.In this study,we used a combination of indoor tests and outdoor field experiments to select a robust reduction soil sterilization method to treat Astragalus continuous crop soils.When mixed and added singularly,we studied the treatment effects of Astragalus straw,Angelica straw,corn straw,and cow manure.The study also investigated the differences in soil microbial community structure between different treatments,intending to clarify the effect of soil sterilization with various additives and provide a scientific basis for soil improvement of the succession cropping in Chinese herbal medicine in our province.From the study,we got the following main results.(1)The results of indoor and field tests of reductive soil disinfestation treatment showed that the soil redox potential(Eh)in all treatment groups decreased to a negative value,and the soil Eh fell to a limited extent in the treatment of only watering,which indicates that only watering without adding organic materials could not fully form an anaerobic environment.Reductive soil disinfestation treatment significantly increased soil organic carbon and ammonium nitrogen content,indicating that this treatment positively affects fertilizer fields.Except for the addition of angelica straw,the nitratenitrogen significantly reduced the range of other treatments,indicating that reductive soil disinfestation has the effect of removing nitrate-nitrogen from the soil.(2)The laboratory test of reductive soil disinfestation showed that compared with the pre-treatment soil,the treatments of adding cow dung,adding Astragalus straw,and irrigation only significantly increased the abundance of bacterial community diversity;the other treatments significantly decreased the abundance and diversity of the bacterial community.All treatments significantly reduced the abundance and diversity of the fungal community.Fusarium significantly reduced the lot and variety of the other groups except for the irrigation-only treatment group.(3)The field test of reductive soil disinfestation showed that the soil temperature ranged from 16.6 to 77.6 °C with different additives during the treatment period.The soil temperature of the treatment with cow dung was the highest.Except for the irrigation group,the bacterial diversity and fungal diversity were significantly decreased.Except for adding Astragalus straw,the abundance of various phytopathogenic fungi reduced considerably in other treatment groups.The quantity of different beneficial bacteria increased in all treatment groups.(4)Combining the changes in soil properties and microbial community structure,corn straw-cow dung and Astragalus straw-cow dung as organic materials added reductive soil disinfestation treatment effect is better.Which can entirely kill various pathogens in the soil Fungi can also improve soil physicochemical properties.