| Objective:With the advanced considerably development of traditional Chinese medicine,pharmaceutical,and chemical industries,the demand for Pogostemon cablin（Blanco）Benth.increased year by year.What’s more,the continuous cropping（CC）obstacle resulted in the decrease of cultivation area and quality of P.cablin,which seriously restricted the development of P.cablin planting industry.To achieve safe,effective,orderly and sustainable production of Chinese medicinal materials,ecological planting was more in line with the production characteristics of medicinal plants,which could solve problems of CC obstacles and declining quality in planting medicinal plants.Therefore,the feasible ecological intercropping pattern scheme of P.cablin was studied and established,the ecological planting adaptability regionalization of P.cablin was carried out by using ecological model,and the current and future cultivation distribution areas of P.cablin were predicted,which provide theoretical basis and technical support for solving CC obstacles and planting problems of P.cablin.Methods and Results:（1）Four different ecological planting patterns of P.cablin were established.When the P.cablin was harvested,the soil from the rhizosphere in the four patterns were collected.The p H,nutrient composition and soil enzymes activities of P.cablin rhizosphere soil under different planting patterns were studied.The rhizosphere effect and ecological change trend of P.cablin intercrop pattern were revealed,whcih clarified the effect of ecological intercropping mode on P.cablin rhizosphere.After P.cablin CC,the results showed that organic matter（OM）increased by 36.58%,available nitrogen（AN）increased by 12.86%,available phosphorus（P）increased by 72.60%,available manganese（Mn）increased by 23.10%,available boron（B）increased by 52.09%,soil p H decreased by 4.11%,and available potassium（K）decreased by 38.92%,exchangeable calcium（Ca）decreased by 16.11%,indicating that the absorption ability of CC P.cablin to OM,N,P,Mn and B decreased,while the absorption of K and Ca were more,which may be the main cause of CC obstacle of P.cablin.After P.cablin intercrop with turmeric or ginger,the change trend of p H,K and Ca content was improved,indicating that the ecological intercropping pattern of P.cablin could alleviate the unbalanced absorption of P.cablin on soil nutrient level and significantly improve the absorption level of P.cablin rhizosphere on soil nutrient.After intercropping P.cablin with turmeric or ginger,the soil enzyme activity showed significant variation,which was involved in the cyclic absorption of soil nutrients and was participated in the life metabolism of P.cablin.Ultimately,the drawbacks of P.cablin’s CC obstacles was alleviated.（2）Microbial diversity,colony structure,community composition and community functional diversity were analyzed by high-throughput sequencing,whcih elucidated the influence of ecological intercropping pattern on the rhizosphere soil microbial community of P.cablin.The results showed that with CC P.cablin intercroping with turmeric or ginger,the abundance was improved,the diversity was increased,the community structure was optimized,and the metabolism of soil bacteria was greatly enhanced.The community analysis of rhizosphere microorganisms in P.cablin was carried out by using the heat map and LEf Se.The results showed that rhizosphere beneficial microorganisms of P.cablin might be included Actinobacteria,Verrucomicrobia,Acidobacteria,Bacteroidetes,Mortierellomycota,and Glomeromycota.Basidiomycota might as the harmful fungi.These microorganisms have crucial influences in P.cablin’s rhizosphere microbial world.Redundancy analysis（RDA）results indicated that the P.cablin ecological intercropping pattern regulated the changes of p H and Ca’s contents,which influence soil physicochemical properties.Ultimately,this pattern affected the distribution of rhizosphere microorganisms of P.cablin.（3）The agronomical traits and the baiqiuli’s content under different ecological planting patterns elucidated the effect of ecological intercropping patterns on the agronomical yield and chemical quality of P.cablin.After intercropping turmeric,the whole plant fresh weight of P.cablin increased by 36.25%.After intercropping ginger,the whole plant fresh weight of P.cablin increased by 23.15%.The result of baiqiuli’s content levels:intercropping turmeric pattern>intercropping ginger pattern>non-CC P.cablin monoculture pattern>CC P.cablin monoculture pattern.In summary,the ecological intercropping pattern could alleviate the decline of agronomical yield and chemical quality caused by CC obstacles,and the turmeric pattern was better than the ginger pattern.（4）Based on 28 records of P.cablin planting and 19 climatic factors collected from field visits,Max Ent model combined with Arc GIS was used to analyze the important climatic factors affecting P.cablin’s cultivation.The potential cultivation areas of P.cablin in China’s current and future was predicted by thse softwares.The work showed that the annual average temperature,the average temperature in the warmest season,the lowest temperature in the coldest month and the average temperature in the dryest season were the most significant climatic factors affecting the regional distribution of P.cablin.At present,the southwest of Guangdong,the south of Hainan and the middle of Guangdong are highly suitable for planting P.cablin.,while the south of Guangxi and beyond the middle of Guangdong are moderately suitable for planting P.cablin;In the future climate environment,in addition to climate scenario-CO2 emission scenario RCP2.6-2050s mode of P.cablin moderate suitable planting area,suitable for P.cablin planting area may expand in the 2050s and 2070s.Conclusion:This work showed that the reduction in the disadvantages associated with CC can be divided into four main aspects.First,ecological intercropping is beneficial to the growth of microbe by adjusting the soil nutrient levels（p H,K,Ca,）.Second,the improved soil microenvironment significantly changes the abundance of different microbial species.Third,Ecological intercropping regulates microorganism metabolism,and Fourth,beneficial microbe and soil physical and chemical factors begin to positively influence each other.The RDA and relativity analysis revealed p H and Ca were the primary factors affecting the dynamic changes of rhizosphere microbial community structure in P.cablin.This work combined ecological model with geographic information system can supply scientific basis for the cultivation of P.cablin,and even provide reference for the sustainable development of other medicinal plants. |
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