| As a major factor, soil enzymes not only influence soil productivity and crop yield,but also reflect the function and effect of soil management. Soil enzymes participate in soilformation and development and accelerate the compounding and discomposing process ofsoil humus, besides, soil enzymes play a great role in such processes as the formation ofsoil fertility. The study on the soil enzymes and enzymatic activity have been popularlyused to assess soil fertility, distinguish the development mellow degree of soil, and oftenbeen used to evaluate the effects of different agricultural measurements and fertilization.Furthermore, the study on the dynamic and thermodynamic characteristics of soil enzymeshelps us to understand processes of bio-chemical reactions and mechanisms that enzymesplayed.Based on the long-term fixed experimental soil, this paper studied the successionorderliness of soil physic-chemic properties and enzyme in fertilizing process. In addition,the enzymes' dynamic and thermodynamic characteristics were discussed. Moreover, thesensitivity of soil enzymes used to indicate soil fertility was also researched so as to find anew way in reasonable management of soil resource, provide scientific evidence to makesoil fertility develop sustainly. The main results are as follows:1. Long-term fertilization improved soil enzymatic activities and soil fertility intopsoil. The effects of fertilizations on improving soil fertility were in the order of Manurecombined with chemical fertilizers>Chemical fertilizer>Control. The results of correlation,path and principal component analysis showed that soil urease and alkaline phosphatasecould be used as sensitive indexes to indicate soil fertility.2. Long-term fertilization exerts strong effects on the distribution of soil enzymaticactivities in soil profile. In 0-40cm soil enzymatic activities have enhanced distinctly;activities of urease, alkaline phosphatase, and invertase are reduced with the increment ofsoil depth except polyphenol oxidase. Furthermore, activities of soil enzymes in each soildepth correlates with soil organic matter contents in corresponding depth. Fertilization canimprove soil quality in deeper soil layers, it has more important practical significance inagriculture of arid area.3. Fertilization augmented the amount of aggregate and characterizedmicro-aggregate in soils, improved the quality of soil structure significantly. The MWD ofsoil aggregate and C/F0.01 of characterized micro-aggregate in fertilization treatments werehigher than in control.4. Long-term fertilization increased the variance of soil chemical and biologicalproperties in soil micro-environments. In the same fertilization treatment, the mainnutrients content and enzymatic activities decreased with the increasing of diameter of soilaggregate in most cases. Besides, the indexes above presented the highest content oractivity in the characterized micro-aggregate less than 0.01 mm in all the treatments exceptthe alkaline phosphatase and invertase in manure treatment. The distribution of the mainnutrients content and soil enzymatic activities presented as the order of BM>MS>CF>CKin the same aggregate and characterized micro-aggregate. Under different spatial scalesand managing treatments, soil properties showed the complexity and diversity of variance.5. Activities of soil urease and alkaline phosphatase increased and reached to aconstant with prolonging of incubation time. Moreover, activities of soil urease andalkaline phosphatase were always higher in fertilization treatments than in controltreatment. The V0 of soil urease and alkaline phosphatase increased with the rising oftemperature and reactant concentrations until they reached a certain value. The V0 ofdifferent fertilizations showed the same order of BM>MS>CF>CK.6. The dynamic and thermodynamic parameters could show the difference of suchreactions' mechanisms in each tested soil in various aspects. the Vmax, Vmax/Km and kincrea...
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