Function Of Earthworm Bioreactor And Its Mechanism Of Driving Soil Microecological Health

Chinese coastal area is rich in tidal flat resources,and its rational utilization and development is of great significance to the protection of food security in China.The application of biological organic fertilizer is one of the effective measures to improve the saline-alkali land of tidal flat,which can improve the physical and chemical properties of salinized soil,enhance soil microbial activity,and promote the transformation of salinized soil into benign soil.Earthworm manure is more effective than ordinary organic fertilizers in improving soil and promoting plant growth.The production and utilization of earthworm manure has broad prospects for development.However,at present,earthworm breeding lacks unified standardization,and the quality of earthworm manure cannot be effectively guaranteed.Therefore,producing highquality earthworm manure has become an urgent matter to achieve sustainable agricultural development.Inulin,as a reserve plant polysaccharide,is widely found in many plants and can effectively improve the composition and structure of human intestinal microorganism.Although a large number of studies have reported that inulin has a probiotic effect on human intestinal flora,whether inulin plays a probiotic role in earthworm culture as a new green residue free feed additive has not been reported yet.This study with cattle manure,Eisenia foetida and inulin as material,set up pure cow manure earthworm breeding(EM)and inulin added cattle manure earthworm breeding(IEM),every 10 days sampling analysis,through a period of 40 days earthworm cultivation experiment,to explore the inulin plays in the process of earthworm breeding experiment,aims to reveal the cow manure-earthworm gut contents-common earthworm manure and inulin type earthworm manure dynamic change the nature of the process,for the high quality of earthworm manure provide theoretical basis for the preparation and quality control and technical parameters.The main results are as follows:1.In the process of feeding,digestion and excretion by earthworms,earthworm feces of common earthworm manure and the inulin type earthworm manure.Their properties are similar: p H tended to be neutral,electrical conductivity decreased significantly,nitrogen was absorbed and utilized,organic matter accelerated decomposition and mineralization,and phosphorus and potassium were further released.The addition of inulin improved the degradation efficiency of organic matter and the release of potassium.After 40 days,the organic matter in IEM treatment decreased by9.4% and the total potassium content increased by 13.0% compared with EM treatment.2.The activities of urease,alkaline phosphatase and catalase in pure cattle manure treatment increased at first and then decreased,and the peak value appeared on 20d～30d.The addition of inulin treatment shortened the time of peak enzyme activity(except for urease).Alkaline phosphatase and Catalase activities reached their peaks at 10 days,and their values were increased by 113% and 61.0% respectively compared with pure cattle manure treatment.Thus accelerating the decomposition and mineralization process of organic materials and promoting the formation of high quality earthworm manure.The abundance of functional bacteria in earthworm manure was increased after the addition of inulin,which improved the biological activity of earthworm manure,and confirmed the probiotic effect of inulin in the formation of earthworm manure.3.The feeding and digestion activities of earthworms provided excellent environmental conditions for the growth and reproduction of microorganisms,significantly improved the microbial diversity of the two kinds of earthworm manure,and selectively regulated the abundance of specific microbial groups.The addition of inulin increased the relative abundance of Actinobacteria in the early and middle periods(10 and 20 days),and increased by 40.7% compared with the pure cattle manure treatment at 20 days.Combined with the analysis of environmental factors,the results showed that TP,O.M,TK,MBC and TN had the strongest correlation with the species at the phylum level and order level,and TP and TK had opposite correlation with O.M,TN and MBC on the same species of bacteria at the phylum level and order level.4.In saline soil cultivation matrix,for comparison,add cow manure,earthworm manure and inulin for 30 days pot experiment of brassica chinensis,the results show that in the saline soil at the same time adding earthworm manure and inulin grows the best of brassica chinensis,increase the emergence rate and emergence speed of brassica chinensis,alleviated the growth restriction of high-salt sandy soil on brassica chinensis,significantly improved the brassica chinensis plant height,leaf area and biomass per plant,promoted the brassica chinensis root development,and doubled the total root length,root surface area and total root volume.