Effects Of Earthworm Inoculation With Organic Materials On Soil Structure And Tea Quality Of Tea Garden

Tea tree(Camellia sinensis(L.)O.Kuntze)is an important agricultural cash crop in China.Tea is preferred over other beverages due to its role in health.Soil fertility is major indicator for the normal growth of tea.Soil organic matter(SOM)content is the evaluation factor of soil fertility and soil fertility.Studies have shown that the stability of soil organic matter and soil amorphous minerals is utmost in the presence of organic and inorganic complexes.Activities of earthworms such as feeding,excreting,secreting mucus and movement can significantly improve soil structure and soil fertility.In order to explore the effects and mechanisms of different dosing methods of earthworms and organic materials on the physical and chemical properties and structure of soil in tea cultivation,this study was conducted using 8 treatment groups(CK,CO,JO,TO,BE,CE,JE,TE)in indoor pot experiments,and analyzed on underground and aboveground parts..For measurement of underground part,Synchrotron radiation based Fourier Transform Infrared Spectroscopy(SR-FTIR)was used to study the microscopic imaging law of soil aggregates,the existence form of soil organic carbon,and the correlation between clay minerals and macromolecular organic functional groups under different fertilization methods.The physicochemical properties and mineral contents of soil were determined by chemical routine method.To assess the aboveground part,the contents of theanine and tea polyphenols in pot experiment were determined by chemical method to reveal the influence of different ways of fertilizer application on tea quality.The results from earthworm inoculation combined with organic materials on the soil structure and tea quality using synchrotron radiation technique and chemical quantitative method are as follows:1.The results of pot experiments with different fertilizer cultivation methods showed that the application of fertilizer alone leads to soil acidification,and the soil acidification phenomenon was more obvious with extended years of planting,and the soil pH value still declined even under the activities of earthworms.Earthworm inoculation with organic materials delayed soil acidification,and improved soil total carbon content,soil total nitrogen content and organic matter content,thus,improve soil fertility.Earthworm activities can promote the decomposition of organic materials in the soil of tea garden and improve the fertility of organic materials.2.Simultaneous radiation infrared microscopic imaging test results of soil aggregates showed that polysaccharides,proteins,fats and clay minerals are highly heterogeneous.Among them,the distribution pattern of clay minerals and polysaccharides are similar,and that of proteins and fats are similar.There are large differences in the distribution of minerals,proteins and fats.The determination coefficients(R~2)of clay minerals and organic functional groups are as follows:clay mineral-protein,clay mineral-polysaccharide,clay mineral-fat,and the affinity are different and not affected by earthworm activity and fertilization treatment.However,inoculation with earthworms and application of organic materials can promote the enhancement of the binding ability of macromolecular organic functional groups and minerals,and improve the soil retention capacity.3.The research on soil minerals under different fertilization methods shows that soil organic matter is the core of soil fertility,and the stability and accumulation of soil organic matter cannot be separated from the existence of soil minerals.The combination of soil minerals and soil organic matter can improve the stability of soil organic matter and thus improve soil fertility.The soil mineral content could not be effectively increased by organic material alone,but could be significantly increased by earthworm inoculation combined with organic material.Earthworm inoculation could not improve the colloid extraction rate,but could improve the soluble organic carbon(DOC)content.4.The results showed that the growth quality of tea was determined by the soil fertility level.Tea growth improved in soil rich in organic matter,therefore,single fertilization was not ideal for promoting the tea quality,while the inoculation of earthworm with organic materials had a positive effect on improving the quality of tea seedlings,amino acids and effective components of tea polyphenols.Application of biochar was considered as the effective way to improve the quality of tea seedling,the content of amino acid and the content of tea polyphenol..In summary,the simulation results of earthworm inoculation and application of organic materials show that single application of fertilizer has no obvious effect on improving soil organic matter content,soil mineral formation,dry weight of tea seedlings,theanine and tea polyphenols content;while long-term application also causes soil pollution such as soil acidification.However,earthworm inoculation combined with different organic materials can improve the content of soil organic matter,promote the formation of soil aggregates,improve the stability of soil organic matter,improve soil fertility,increase dry weight of tea seedlings,theanine and tea polyphenols content,so as to improve the quality of tea.It is found that soil mineral can combine with soil organic matter,improve the content and stability of soil organic matter.Soil mineral can increase soil aggregate structure,improve soil permeability,and improve water and fertilizer retention capacity while improving soil carbon sequestration capacity.This provides a direct basis for soil management and improvement of tea yield and quality.