| Conservation tillage was an improvement of traditional farming methods, which was a perfect way of farming. We used to measure whether it is conservation tillage by the coverage of traw stubble, if the coverage was more than 30%, it was thought conservation tillage. It was contained with the technology of straw muLch tillage, minimum tillage, no-tillage, subsoiling, preventment of slope erosion, rational use of water, pesticides and fertilizers, crop rotation and so on. Conservation tillage couLd protect the farmLand, improve soil structure, increase farmers’income and protect the environment, it laid the foundation for the development of sustainable agricuLture, therefore, conservation tillage research was of important significance. Meanwhile the celluLose degrading bacteria were dominant in straw degradation.The research was carried out in 2006 corn season. Four samples were set according to whether tillage and whether the straw were returned. The soil samples were collected in April 2012. The effect of the four treatment to the soil enzyme activity and soil bacteria and fungi diversity and diversity of the cbhl genes. The resuLts are as follows.1) The measurement of the physical and chemical properties showed that, in the four kinds of soils with four different treatment, the quantity of total nitrogen, organic carbon, total phosphorus, total potassium, nitrogen, phosphorus, potassium were as follows: CNTWNTS>CNTWTS,CNTWNT>CNTWT>CNTWNTS>CNTWNT,CNTWTS>CNTWT。Among these four treated soils, CNTWNTS soil had the highest quantity of the six properties. The soil PH had no significant differents.2) Measurement of the number of microorganisms in the four different soils showed that, in the CNTWNTS treated soil, the number of the bacteria, fungi and actinomycetes were higher than other treated soil. Straw muLching soil had higher number of bacteria, fungi and actinomycetes than no straw muLching soil, and tillage sowed soil had higher number of bacteria, fungi and actinomycetes than no tillage sowed soil.3) Measurement of the enzyme activity showed that the activity of the tainverse in the no-tillage soil were higher than tillage sowed soil, and straw returned soil were higher than no straw returned soil; The activity of the invertase were the highest in the CNTWNTS soil, which was 13.55(Glucose mg/g soil·24 h),56% higher than other tillage soil. The catalase activity in the straw-covered soil was higher than no straw-covered soil, and the no-tillage soil were higher than tillage soil; The catalase activity were the highest in the no-tillage soil, which was 2.617(0.1 KMnO4 mL/g soil·1 h),11.6% higher than the lowest catalase activity in CNTWNT soil(0.1 KMnO4 mL/g soil-1 h), which was 2.335. The celluLose activity in the straw-covered soil was higher than no straw-covered soil, and it reached the highest in the CNTWNTS soil, which was 15.29(Glucose mg/g soil·24 h),47.3% higher than the lowest activity in CNTWNTS soil, which was 15.29(Glucose mg/g soil·24 h).4) The analysis of soil bacteria and fungi diversity in the four different soils by the method of PCR-DGGE showed that straw return and zero tillage couLd both improve the microbial community diversity. The Shannon index of the straw returned soil bacteria were higher than no straw returned soil. The 24 sequences belonged to Proteobacteria, Actinomycetes and Verrucomicrobia. Among which, Actinomycetes were dominant bacteria. The Shannon index of the straw returned soil fungi were higher than no straw returned soil. The 18 sequences belonged to Basidiomycota and Ascomycota, among which, Ascomycota were dominant bacteria.5) The analysis for biodiversity of cellulose-degrading gene cbhl via PCR-RFLP revealed 44 OTUs, suggesting that the CNTWNTS treatment can increase the biodiversity of gene cbhl significantly.Analysis of celluLose degradation gene cbhl by the method of PCR-RFLP showed that the genes were belong to Ascomycota and Basidiomycota. Basidiomycota were the dominant bacteria. |
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