| As a protective tillage ,No-tillage and ridge culture (NT) is a kind of culture mode to minimumize the land cultivating (including cultivating intensity and cultivating times).It means leaving the plant residue after harvesting. Under this principle, the NT system is also called limited tillage, zero-tillage, chimical-tillage, no-plowtillage, straight sowing, mulch-no-tillage and protective-tillage etc.In our country, the land is limited. The cultivated land is decreasing and is seriously occupied and destroyed. Study is in need for high production and the aim of best ecological, economical and social effects without destroying land resources. Therefore, it is necessary to carry out the sustainable development of agriculture and track a path to ecological agriculture.The first NT began in primitive society. It was a culture mode adopted under the condition of low productivity and poor tools. Recent No-tillage and ridge culture commenced in the United States in the 1930s. It was developed to prevent the erosion of water and soil and to avoid the wind and water erosion. Not until the atrazine herbicide was invented and successfully used in the 1960s was the NT technique succeeded and spread. Based on the mulch no-tillage of the United States, more than 40 countries, such as Canada, Australia, New Zealand, Japan, England, France, Spanish, Brazil, etc, were engaged in a study on the NT or ZT. and made a great achievement.The study of NT began in the 1950s in our country for high yield. The experiment indicated that long-term of NT could improve the soil's physical structure and the soil's sluice capacity, and could aggregate the accumulation of various nutrients in soil and increase plant yield.In research much importance was attached to the study of dry land and the physical, chemical and biologic properties of water land, but the relationship between soil microbes and soil fertility in the paddy field of long-term no-tillage and ridge culture was relatively ignored,so this experiment was conducted for further study. We mensurate the number of the primary soil microbes such as bacteria, fungi and azotobacter with diluting flat technique, and mensurate the number of cellulose decomposing bacteria with MPN technique, and mensurate the biological quantity of the soil microbes with the technique of chloroform suffocating-inundation culture-colour-compared. The normal analytic technique was adopted to mensurate the basical nutrients such as total N, total P, total K, available N, available P, available K, organic matter, pH and so on. Meanwhile, various techniques were employed to mensurate the soil dissoluble carbon, finally the technique of water saturating-H2SO4-AgSO4-Circumfluence-FeSO4 titration was used in this experiment.The basic fertility characteristics, and soil microbes and the relationship between them were investigated on paddy fields of purple soil, where no-tillage and ridge culture had been practiced for twelve years. The advantages and disadvantages were contrasted among five culture modes (conventional culture, no-tillage and fallow in winter, no tillage and ridge culture, no-tillage and box culture, and the rotation of paddy and upland). The main causes of more nutrient and higher output in NT were found in this experiment which was the more input of residue, and better match was explored for the reside decomposing among the microbial composition, organic or inorganic fertilizers.Though the study on the long-term of no-tillage and ridge culture in this dissertation, the research results are as follows:1) NT can change the wee terrain and change the conditions of air and water, which leads to the seasonal fluctuation of the main kinds of microbes such as bacterica, foungi, azotobacter and cellulose decomposing bacteria.2) There is difference between the laws of different kinds of microbes. The quantity of bacteria, fungi and azotobacter is high in spring and winter and low in summer and autumn while the quantity of cellulose decomposing bacteria is higher in spring and...
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