Research On The Disposal Method Of Leafy Vegetable Residues By Fertilizer

At present,a large number of leafy vegetable wastes are produced in large-area vegetable greenhouses in China.These wastes are various,large in quantity and difficult to degrade.If they are not disposed properly and effectively,it will not only cause the waste of resources,but also lead to serious environmental pollution.In order to solve this problem,we screened out cellulose,starch,protein efficient degradation strains and nitrifying bacteria which can effectively retain nitrogen from the environmental humus layer in this study,studying the growth and organic matter degradation characteristics of each strain.Subsequently,we optimized and developed a compound microbial inoculant which can be used for the fertilizer treatment of cabbage,chinese cabbage,green leaves,etc.,and related equipment has been developed to realize the resource disposal of leafy vegetable wastes,which has a promising marketability prospect.The main results are as follows:（1）Through the transparent circle degradation experiment and determination of enzyme activity,four strains functioned in organic matter degradation were screened,named M1,M2,M3,M4 and one strain of nitrifying bacteria marked as M5.The five strains were identified as Bacillus cereus（KY622400.1）,Bacillus sp.bh3（KX011932.1）,Bacillus sp.bh1（KC121041.1）,Bacillus sp.bh2（MH769260.1）and Gordonia（JN695028.1）by molecular biology methods,respectively.Among them,M1 and M2 had strong cellulose degradation ability,M3 had both cellulose and starch degradation ability,M4had both cellulose and protein degradation ability,and M5 served as nitrifying bacteria.（2）Through the single factor experiment to study the growth and organic degradation characteristics of the selected strains,the optimal growth conditions for the five strains were as follows:M1（temperature:28℃,p H=7）,M2（temperature:28℃,p H=7）,M3（temperature:37℃,p H=8）,M4（temperature:37℃,p H=8）,M5（temperature:28℃,p H=7）.The cellulase activities of M1,M2,M3 and M4 reached the peak value at 48 h,which were 0.51 IU/m L,0.53 IU/m L,0.56 IU/m L and 0.56 IU/m L,respectively,and the amylase activity of M3 reached the peak value of 0.22 U/m L at 48h,and the protease activity of M4 reached the peak value of 54.40 U/m L at 36 h.（3）The antagonistic effect of five strains was verified,and no antagonistic effect was observed among them.On this basis,two kinds of compound microbial inoculant products were prepared.The total number of bacteria in the product was 4×10¹⁰/1g,and the rate of mixed bacteria was less than 25%.The product could be preserved for six months.At the same time,we established an equipment,which integrated multi-function of crushing,stirring and fermentation for fertilizer treatment of vegetable waste,solving the problems of self-crushing,unsatisfactory fermentation effect and long fermentation period in existing equipments.（4）The two prepared compound microbial inoculants were used in the compost test of leafy vegetable wastes such as cabbage（cabbage）,Chinese cabbage（Chinese cabbage）,green leafy（small green cabbage）,etc..It was shown that compared with the control group,the addition of complex microbial inoculant No.1 and No.2 could shorten the retting time of the three leafy vegetables by 4～6 days,respectively.The compound microbial inoculant No.1 greatly increased the total nitrogen content in the liquid fertilizer,which for the cabbage,chinese cabbage and green leaves increased by 40.61%,17.92%and 16.53%,respectively.Whilst,the compound microbial inoculant No.2 significantly increased the nitrate nitrogen content,which for cabbage,chinese cabbage and green leaves increased by 6.67%,18.82%and 14.92%,respectively.The addition of compound microbial inoculant No.1 and No.2 speeded up the degradation rate of organic matter.After different leafy vegetable wastes were retorted,the GI value reached over 50%after the retting fertilizer stock solution was diluted by ten times,and some groups reached more than 80%.Therefore,the two compound microbial inoculants did not induce toxicity to seeds and plants and could be applied in farmland.（5）The enzyme activity changes of the two compound microbial inoculant were detected and analyzed during the compost process of cabbage,chinese cabbage,and green leafy vegetable wastes.The results showed that the cellulase activity,a parameter reflecting the degradation process of carbon in composting,exhibited a stable decline trend in the three treatments.The activities of protease and amylase showed a trend of decreasing first and then increasing and reached the lowest on the 7th to 9th day,indicating that the liquid organic fertilizer could be completed in 7 to 10 days under the conditions of 20～25℃at ambient temperature with the addition of compound microbial inoculant.The number of bacteria in the fermentation product was 10¹⁰ cfu/m L,which was much higher than the requirement specified in the national liquid organic fertilizer standard（10⁶cfu/m L）.In addition,no fecal E.coli was detected in organic fertilizer products.