Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Preparation of Compound Microbial Fertilizer and Its Effect on Soil Improvement in Northwest Arid Mining Areas

Auteur : 许奕琳

Grade : Master 2022

Université : Inner Mongolia University of Science & Technology

Résumé partiel
The long-term over-exploitation of mining areas has brought about a series of environmental problems,while the dry climate,scarce rainfall and poor soils in the northwest have severely restricted the process of ecological restoration of abandoned mine sites.Compound microbial fertiliser combines the advantages of organic fertiliser and microorganisms and can improve the soil in mining areas very well.Therefore,in this study,six strains of Phosphate bacteria,Potassium bacteria and Diazotroph bacteria were selected from sheep manure for isolation and purification,and a composite bacterial agents was prepared,as well as the addition of biochar to prepare a biochar/microbial agent complex suitable for composting experiments.The aerobic composting of sheep manure and maize straw was carried out by adding biochar/microbial agent complex（BM）,biochar（B）and composite bacterial agents（M）to the piles to investigate the effects of different treatments on the physicochemical properties,nitrogen cycling,gas emissions and bacterial community succession during the composting process,and to conduct a comprehensive evaluation of the fertilisation efficiency by principal component analysis.Finally,a 30-day experiment was conducted to comprehensively evaluate the effect of the compound microbial fertilizer on soil improvement through principal component analysis,with a view to providing a theoretical basis for soil improvement in mining areas.The following conclusions were mainly obtained :（1）Two strains of inorganic phosphorus removal bacteria,two strains of organic phosphorus solubilizing bacteria,one strain of potassium bacteria and one strain of diazotroph bacteria were isolated and purified from fresh sheep manure taken from farms in Jiuyuan District,Baotou City,Inner Mongolia.It was also prepared as a biochar carried microbial agent to enable the microorganisms to successfully attach to the biochar.（2）The addition of biochar/microbial agent complex allows the compost to warm up quickly and extended thermophilic stage up to 9 days,while avoiding an anaerobic environment and to make the proportion of clumps<4 mm higher than 80%.After composting,the BM treatment group obtained lower E4/E6values and higher GI values,indicating that the addition of biochar/microbial agent complex accelerated compost stability and reduced phytotoxicity.In addition,the addition of biochar/microbial agent complex had a beneficial effect on the degradation of organic nitrogen and the rapid conversion of NH4+-N to NO3—N.Compared to CK,the BM treatment group reduced CH4,NH3and N2O emissions by 65.79%,42.05%and 68.64%respectively,contributing to a better reduction of greenhouse gas emissions.

Mots clés : Complex microbial agent ;Biochar;Compost ;Soil improvement ;

Présentation (CNKI)