Study Of Effect Mechanism For Cropland Soil Micro-ecology On Angelica Sinensis Seedling Nursing In Min County

Angelica sinensis is a medicinal plant belonging to Umbelliferae.Min and Zhang Counties of Gansu Province are high-quality genuine production areas for A.sinensis.Traditional seedling nursing in uncultivated wild meadow field lead to habitat destruction.Early bolting and root rot make the cultivation effect decline,and the trend of abandoning cultivation aggravates.Exploring seedling nursing in cultivated land is an important way for sustainable development of A.sinensis industry.In this study,based on the previous study of the rotation selection in the matured land,Astragalus membranaceus(HQ)and fallow abandoned(LH)rotation were cultivated following pea rotation in the matured cultivation field of A.sinensis in Min County,a real estate area.The plant seedlings were nursed in the cultivated rotation fields,and the seedlings in the wild meadow land(SH)were used as the control.In order to explore the soil microecological factors that affect the seedling growth of A.sinensis in matured land and provide a scientific basis for the selection of excellent rotation systems for A.sinensis in matured land,the main results are as follows:1.The activities of catalase(CAT)and urease(URE)were significantly increased by the rotation of HQ residues.The activity of URE was the highest in the field of A.sinensis seedling with LH stubble.The activity of soil invertase and phosphatase was significantly increased by SH,but the activity of CAT was decreased.With the development of the plant seedlings,the soil IIIucrose in the medicinal plant seedling field in each rotation was higher in the harvest period than in the vigorous growth period.The range of soil p H was 6.81-8.24at different seedling stage,with the order as LH>HQ>SH.SH could significantly increase soil electrical conductivity and organic matter during vigorous growth period,and total nitrogen and phosphorus contents during vigorous growth period and excavation period.At the same time,the contents of soil available P and K in the seedling field of A.sinensis were significantly reduced by SH stubble.HQ and LH stubbles could significantly increase the contents of available potassium,K~+and Na~+in seedling field of A.sinensis during vigorous growth period and the contents of available phosphorus during harvest period.The results showed that HQ and LH stubbles were not conducive to the absorption and utilization of available nutrients in A.sinensis,however,the soil micro-ecological environment formed by SH stubble might be conducive to the absorption of available nutrients in soil by A.sinensis seedlings.2.The relative electrical conductivity,leakage rate of amino acids,soluble sugar content,malondialdehyde(MDA)content,autoxidation rate and peroxidase(POD)of roots of A.sinensis seedlings with HQ stubble were not significantly different from those of seedlings with LH and SH.Although the leakage rate of amino acids and autoxidation rate of roots of SH seedlings was lower and the activity of CAT was stronger and the bolting rate was lower,the relative conductivity of roots of the plant seedlings after HQ stubble was lower,and the activities of SOD and POD were stronger,which maintained the MDA in a lower concentration range,and the rejuvenation potential was higher after transplanting.3.The dominant bacteria in rhizosphere of A.sinensis seedlings in different stubbles were Actinobacteria,Proteobacteria,Bacteroidetes,acidobacteria and Chloroflexi.The Actinobacteria increased with seedling growth.The dominant fungi in different stubbles were Ascomycota and Basidiomycota.With the growth and development of seedlings,the relative abundance of Ascomycota decreased,but the abundance of Basidiomycota and Mortierellomycota increased.The relative abundance of other fungi fluctuated.The relative abundance of unclassified Fungi was significantly higher in SH than that of HQ and LH residues.4.There was a correlation between rhizosphere bacteria and environmental factors in A.sinensis seedlings nursed soils at different stubble sample sites,and the activities of CAT and URE enzymes were positively correlated with the stubble of LH and HQ.Activity of PHO and INV was positively correlated with the SH,which was more easily affected by the bacterial community in the treated soil.The microbial community was closely related to the growth of RL,RW and RFW in the mining stage.SS,POD,MDA and AR are closely linked to barren land.TP,TN and OM were significantly affected by rhizosphere bacteria in inhospitable soil,while TK and p H were easily affected by rhizosphere bacterial communities in stubble and fallow abandoned soil of HQ.The fungal community in the mining stage was closely connected with the growth of RL,RW and RFW.There is a close relationship between P and SOD and fungal community in the harvest stage.SS,POD,MDA,AR and AAL were closely connected with the fungal community in the flourishing stage.TK and p H were closely connected with the fungal community in the harvest stage.5.The root incidence after overwintering in HQ and LH was different,but there was not significant difference.The root incidence was the lowest in HQ stubble soil.The results showed that the highest yield of A.sinensis was obtained from HQ stubble,which was 17.86%and 3.97%higher than that from LH and SH stubbles,respectively.There was no significant difference in ferulic acid and extract contents.The results showed that the comprehensive evaluation index in production performance for Angelica sinensis seedlings was HQ(0.5597)>SH(0.5070)>LH(0.3976).In summary,the excellent stubble can effectively improve the microenvironment of soils based on the comprehensive indexe evaluation for the excellent stubble soils to cultivate the A.sinensis seedlings.The physiological resistance characteristics of the seedlings cultivated in the HQ stubble soil are close to the original land.Although early bolting rate is slightly higher than that of the seedlings grown in the SH stubble,the incidence of the seedlings is relatively low,and the ability to resist the external environment is strong,and the medicine rate is high.It makes up for the difference in the output of patent medicine.Therefore,HQ stubble is a suitable soil resource for A.sinensis seedling cultivation.These results are expected to provide a scientific basis for changing the traditional pattern of seedling cultivation in uncultivated land and promoting the sustainable development of A.sinensis industry.It is suggested that it should be popularized and applied in the main production areas of A.sinensis.