Screening And Efficacy Study Of Fermented Organic Fertilizer Strains Based On The Biochar Coupled With Livestock And Poultry Manure

Biochar refers to the black carbon rich material which is produced by thermal decomposition of biomass such as(wood,crop straw,livestock manure,etc.)in an oxygen-free or oxygen limited-enclosed environment at a temperature of <700°C.Biochar contain more functional groups and porous structures,therefore it has the high adsorptive and water-holding capacity properties.The p H of biochar is alkaline which can be used to neutralize acidic soils.Biochar organic fertilizer refers to fermented organic fertilizer with biochar,can be slowly released the fertilizer into the soil after use,to improve the utilization of fertilizer.The use of biochar organic fertilizer can improve soil physical and chemical properties,increase soil nutrient content,increase the amount of beneficial microorganisms in the soil,and reduce soil consolidation problems.Through selection of highly efficient cellulose-degrading strains,combined with other microorganisms to make a composite inoculum and added to biochar organic fertilizer fermentation.The following results were obtained:1.Two strains of cellulase activity and filter paper enzyme activity were screened out from the cow manure collected in cattle farms in Lanzhou.The ITS sequency were sequenced by DNA sequencing.The two strains identified were Aspergillus flavus and Aspergillus niger.The two strains were combined with laboratory identified C.lipolytica and Bacillus subtilis in a 1:1:1:1 fermentation to prepare a microbial composite inoculant to accelerate the heating rate of biochar organic fertilizers fermentation.2.By Energy Dispersive Spectrometer(EDS)analysis,the carbon contents of wheat straw biochar,peanut shell biochar and rice straw biochar were 74.23%,69.08%,and 7.45%,respectively.3.The C/N ratio of fermented biochar organic fertilizer was adjusted by adding rice straw powder is 30:1.The single-factor experiment determines the optimum parameters of moisture for the biochar organic fertilizer fermentation,ie,the moisture was 65%,and the compost material was cow dung with sheep manure,the biochar selected was wheat straw biochar with 10% bacterial inoculum.Compared with the control groups,the temperature of composting in the experimental groups were fast,and the fermentation time less.The contents of heavy metals Pb,Cd,As,Hg,and Cr were measured after the biochar organic fertilizer was fermented,they were 11.62 mg/kg and 1.21 mg/kg,9.6 mg/kg,0.54 mg/kg,39.82 mg/kg,respectively.With reference to the national standard NY525-2012 of bio-organic fertilizer,the moisture,organic matter content,and heavy metal content are all in accordance with national standards and can be used as base fertilizer and others.4.The differences in structure,elemental species,and elemental content between wheat straw biochar,peanut shell biochar,and rice straw biochar have different effects on crop growth.Through pot experiment,planting wheat seedlings with the same plant height,after 30 days,the total plant height of wheat grown with biochar organic fertilizer,wheat straw biochar,rice straw biochar,peanut shell biochar,and pure soil was 15.09 cm and 10.18 cm,12.45 cm,8.7cm,and 13.42 cm,respectively.Demonstrating that biochar organic fertilizer can promote plant growth.