Preparation Of Organic Fertilizer From Ganoderma Lucidum Residue And Its Improvement Effect On Saline-alkali Soil

Traditional Chinese medicine residue（TCMR）is a solid substance left after extracting medicinal components from medicinal materials.About 70 million tons of traditional Chine se medicine residue are produced every year in China.Conventional disposal methods,suc h as incineration,landfill and stacking,have the problems of waste of resources and polluti on of ecological environment,and developing them into high-value products is an effective way of resource utilization.In this study,organic fertilizer was prepared by aerobic fermen tation of Ganoderma lucidum residue（GLR）,and the optimum conditions of aerobic compo sting of GLR were determined by indoor composting orthogonal experiment.Organic fertil izer was prepared by natural composting with nano-compost covering film outside;The org anic manure of GLR was used as saline-alkali soil conditioner,and the effects of organic m anure of GLR on saline-alkali soil,physical and chemical properties of soil,microbial com munity structure and carbon source utilization ability were investigated through soil colum n leaching experiment and soil culture experiment.The improvement effect of organic man ure of GLR on saline-alkali soil was explored.The main conclusions are as follows based o n researches mentioned above:（1）The optimal composting conditions of GLR determined by indoor composting orth ogonal test were carbon-nitrogen ratio 35,water content 60%,natural composting and amb ient temperature 30℃;Under the optimal conditions,the contents of total humic acid,wate r soluble humic acid and free humic acid were 350.50 g/kg,88.8 g/kg and 233.59 g/kg,resp ectively.（2）In the process of outdoor natural composting of GLR,the composting temperature exceeded 55℃for 48 days;The fibrous structure of GLR was gradually destroyed and deg raded,and the granules became larger and larger.The moisture content and conductivity of the compost decreased gradually,while the total humic acid,free humic acid and water-solu ble humic acid of the compost products increased continuously,and the maturity period rea ched 397.25 g/kg,260.33 g/kg and 112.30 g/kg,respectively;The conductivity was less tha n 4 m S/cm and the value of E₄/E₆ was 1.14;The organic manure prepared with GLR could be used as soil conditioner because it reached the hygienic standard（temperature>50℃）,h ad high spoilage degree and was in line with the safe application range of soil.（3）GLR organic fertilizer can promote the leaching of Na⁺,Ca²⁺,HCO₃^-,Mg²⁺and Cl^-in saline-alkali soil;After leaching,the p H,conductivity,Na⁺,Ca²⁺,Mg²⁺and K⁺cont ents of saline-alkali soil improved by leaching GLR organic fertilizer were lower than those of control.FSA with 25%organic fertilizer added from GLR has the best leaching desalin ation effect.（4）GLR organic fertilizer significantly increased the contents of available phosphorus,organic matter,hydrolyzed nitrogen and ammonium nitrogen in saline-alkali soil,increase d soil moisture and porosity,and decreased soil bulk density,conductivity and p H value;FS A treatment with 25%organic fertilizer added from GLR improved the physical and chemi cal properties of saline-alkali soil most significantly.（5）GLR organic fertilizer improved soil amylase and sucrase activities,increased the diversity and richness of bacteria and fungi in saline-alkali soil,decreased the relative abun dance of Ascomycota and moderately halophilic bacteria Proteobacteria,and increased the relative abundance of halophilic bacteria Bacteroidota,Firmicutes,aerobic bacteria Actinob acteriota,Chloroflexi and Basidiomycota,and increased the functional gene abundance of Biosynthesis of amino acids,Carbon metabolism and Ribosome pathways.（6）GLR organic fertilizer increased the utilization rate of microbial carbon source in s aline-alkali soil,and the 36-hour average well color development in the GLR organic fertili zer treatment group was significantly increased by 4300%-7700%compared with the cont rol group.The above results showed that GLR can be composted by aerobic alone,the compost p roduct,GLR organic fertilizer,can improve the water-soluble salt ion leaching efficiency,r educe the p H,conductivity and salinity of saline-alkali soil,increase soil fertility,improve s oil enzyme activity,increase soil microbial community diversity,reduce the metabolic func tion abundance of human＿pathogens＿all and animal＿parasites＿or＿symbionts,and improve the utilization rate of carbon source,which has a good improvement effect on saline-alkali soil.This study can provide basic theoretical data and reference experience for improving s aline-alkali soil with organic fertilizer from traditional Chinese medicine residue,and provi de a new way for resource utilization of traditional Chinese medicine residue and biologica l improvement of saline-alkali soil.