Study On Fertilization Treatment Of Vegetable Waste

In order to alleviate the pollution pressure of vegetable waste on the ecological environment and improve its utilization level of resources.In this study,vegetable wastes,livestock and poultry manure,straw and other solid wastes were recycled by artificial fermentation composting and earthworm transformation.The dynamic changes of pH,organic matter,nitrogen,phosphorus,potassium and available nutrients of the mixed substrate during the treatment were studied,and the characteristics of bacterial community structure and effective living bacteria of the earthworm treatment products were analyzed.The main conclusions are as follows:(1)In the process of treating vegetable waste,cow dung and straw by artificial fermentation composting,the high temperature period(>50 C)of each treatment lasted for 6-11 days,and M2(vegetable waste: cow dung: straw 3:1:1)was the best,and the high temperature period lasted for 11 days.When vegetable waste,cow dung and straw are mixed substrates,the maximum temperature of the stack is about 61 C,and when the mixed substrates contain only vegetable waste and straw,the maximum temperature of the stack is 55 C,indicating that adding appropriate amount of cow dung in the substrates can adjust the C/N of the substrates and increase the maximum temperature of the stack.Adding exogenous microbial agents has no significant effect on the maximum temperature of the stack,but can increase the heating rate of the stack.The duration of high temperature period was prolonged.(2)In the process of composting by artificial fermentation,the organic matter content of each treatment decreased sharply during the high temperature period of 0-15 days,and then stabilized.Adding exogenous microbial agents and cow manure to the substrate can promote the decomposition of organic matter.The content of total nitrogen and available nitrogen in the mixed substrate decreased;the content of total phosphorus,total potassium,available phosphorus and available potassium increased gradually due to the "concentration" effect of decomposition of organic matter;the total nutrient content in the treatment added with exogenous microbial agents was higher than that in the treatment not added,indicating that the addition of exogenous microbial agents was beneficial to the accumulation of total nutrient content.The seed germination rate,yield and volume reduction rate of compost products were 88.10-93.33%,49.92-54.53% and 34-45%,respectively.The seed germination rate,yield and volume reduction rate of the treatment with cow manure were higher than those of the treatment without cow manure.(3)Using vegetable waste,cow dung and pig dung as raw materials,two experimental groups were set up,namely,vegetable waste + cow dung,vegetable waste + pig dung.The proportion of vegetable waste in each experimental group was controlled to 30%,40%,50% and 60% respectively,and 10 treatments were used to feed earthworms.After earthworm treatment,the odor of mixed substrates decreased significantly.The total number of viable bacteria in the 10 groups of earthworm treatment products reached 107 orders of magnitude.The content of silicate bacteria and Rhizobium bacteria was the main bacteria in the colonies,accounting for 83.11%~97.79% of the total viable bacteria.Compared with cow manure group,there was no significant difference in the number of silicate bacteria,nitrogen fixing bacteria and Rhizobium bacteria in pig manure treatment group,but the number of inorganic phosphorus bacteria and organic phosphorus bacteria was significantly higher than that in cow manure treatment group.(4)In the process of earthworm treatment,the total nitrogen content of all treatments decreased gradually from 0 to 45 days,then increased from 45 to 60 days.The reduction rate of nitrogen in cow manure test group was higher than that in pig manure test group.Adding straw excipients was helpful to improve nitrogen loss.Total phosphorus and potassium content gradually increased with time.Vegetable waste and cow dung were more conducive to the accumulation of total nutrients.(5)The Shannon index and Chao index of earthworm treatment products were significantly higher than those of conventional organic fertilizers(P < 0.05),indicating that the diversity of microorganisms and the total number of species in earthworm treatment products were significantly better than those of conventional organic fertilizers.Actinobacteria(actinomycetes),Proteobacteria(Proteobacteria),Chloroflexi(Curvularia),Firmicutes(Phytophthora),Bacteroidetes(Pseudomonas)and Planctomycetes(Phytophthora)are the dominant bacteria in earthworm treatment products.At phylum level,the bacterial abundance varied with the type of substrate;at genus level,the genera distribution of earthworm treatment products was more uniform and dispersed,while that of conventional organic fertilizer was more concentrated.Earthworm treatment products were unique to Nocardioides,Rhodobacter,Microbacterium and Gaiella.The results of principal coordinate analysis showed that the products of earthworm treatment had unique community structure and clustered together.