Isolation And Identification Of Cotton Straw Degrading Bacteria And Its Effect On Soil Physical And Chemical Properties

With the swift development of the use of crop straw resources, crop stalks have got more and more attention at present. Straw technology not only reduces the pollution of the environment, but also enhances the fertility of the soil, which is to improve the utilization efficiency of straw most effective way. However,under natural conditions, slow degradation straw lead to straw will affect crop growth and production.Therefore, the study of microbial degradation of straw utilize technology is conducted to solve the problem of the presence of straw.In the cotton stalks mechanical Rotary to field conditions, In order to obtain the strain can be vaccinated and promote rapid degradation of cotton stalks. This test isolated four strains of the cotton stalks for the degradation of the soil of cotton, named SN-1, SN-2, SN-3, SN-4, respectively, after morphology and 26 Sr DNA sequence analysis of Aspergillus niger,Gibberella,Alternaria, Penicillium, respectively.In liquid culture process with cotton stalks as carbon source, the Strain of SN-1 and SN-4 on cotton stalk has a strong ability to degrade, on the first 25 days, its straw weight loss rate reached to 52.47% and49.73% respectively. The strains of SN-1 and SN-4 on degradation of cellulose is the best, besides,cellulose degradation rate could reach to 40.23% and 38.36% respectively. There is little difference among the strain of SN-1, SN-2 and SN-4 for hemicellulose degradation(28.12%, 27.35% and 26.51%). The strain of SN-3 for lignin degradation rate can reach 16.17%. Strain of SN-2, SN-3 for a relatively low rate for cotton straw weight loss and degradation rate of cellulose, But SN-2 for the degradation of hemicellulose prominent, SN-3 for the ability to degrade lignin prominent, description microorganism itself selectivity.In field experiments under natural conditions, soil samples for different treatments, Determination of time-dependent content of organic matter and available nitrogen phosphorus potassium. The results show,compared with strain SN-1 treated straw and two reference significant differences about soil organic matter and NPK data. In the process of cotton straw, the strain field can also improve organic matter and available NPK content in farming soil, thereby improving soil fertility for the impact of deep soil which is less than that of surface soil.The strain of SN-1 deal with cotton straw for field experiments, by measuring soil bulk density, water content and p H, compared with two kinds of reference, the results show significant changes in the surface soil, of which deep soil is less than that of surface soil. Show in the field experiments under natural conditions, inoculum can improve the physical properties of the soil, that can be conducive to the growth and yield of crops.In this study, 4 strains of bacteria were isolated with a certain degradation ability of cotton stalk which can significantly increase soil organic matter content, enhance soil fertility and affect the physical properties of the soil in order to provide a theoretical basis and strain resource for microbial inoculants of cotton straw returning.