Abstract:The evapo-geochemical barriers (EGB) in soils of arid-desert landscapes in Tianshan Mountains, Xinjiang may be divided into carbonate EGB, gypsum EGB, and soluble salt EGB, which are mainly composed of carbonatic soil, gypsic soil, and saline soil, respectively. These EGBs are distributed along Tianshan Mountains as a sequence of carbonate EGB, gypsum EGB, and soluble salt EGB from mountain to basin. In the carbonate EGB, the concentrations of Mn, Ti, Fe, V, Sc, Cu, Co, and B in soils were diluted and lowered as the result of the accumulation of dissociated CaCO₃. In the gypsum EGB, B and Sr in soils were increased with increasing gypsum. In the soluble salt EGB, the accumulation of soluble salts always accompanied with an increase of B, and a decrease of Mn, Fe, Ti, V, K, Ba, Li, F, and Zn in soils due to the dilution of soluble salts. The EGB significantly affected the bio- availability of Fe, Cu, B, F, and Zn as well. The accumulation of dissociated CaCO₃ in the carbonate EGB significantly decreased the bioavailability of Fe, Cu, and B, whereas the bioavailability of B increased with the concentration of soluble salts in soils. Wate-rsoluble F in the carbonate EGBwas high in the soils with high concentrations of CO₃^2- and HCO₃^-. In addition, the bio-availability of Cu is higher in the soils with high organic matter than in the other soils. The bioavailable Zn has significantly positive relationship to the content of clay in soils.

Abstract:Diversity indices and abundance distribution models are statistical tools which ecologists have applied for decades for analyzing the intrinsic regularities of various ecological entities. In this work, similar techniques are used to analyze geomorphic diversity (as an example of geodiversity in a broad sense), and discussions are conducted on the basis of the SOTER digital databases of Hainan Island, China. Through calculation of indices of richness (S), indices of diversity (H') and indices of evenness (E) of landform categories of soil parent materials, and establishment and application of the model of multi distribu tion of landform categories of different soil parent materials, the analysis of geomorphic diversity of different soil parent materials in Hainan in the GIS environment can be expressed digitally.

Abstract:Based on the fractal theory and experimental data in wind tunnel, the fractal character of soil particle size in a short period was preliminarily discussed in this paper. Also, the trend of fractal dimension on soil surface during different deflation periods was analyzed. Some conclusions can be drawn as follows: (1) During the different blowing intervals, fractal structure exists in the grain size distributions of sandy loam and loamy sand. Furthermore, fractal characters of two soils don't change with the different wind speeds and time in the wind tunnel. But their fractal dimensions change as the time gone. (2) Whether the initial stage of deflation or the consequent stage with definite wind speed and time, the fractal dimensions of sandy loam are all smaller than that of loamy sand. (3) During the different soil deflation process, regression analysis indicated that there was significant positive correlation between the fractal dimensions of the grain sizes of the two soils with different texture and the content of the clay(< 0.05 mm), but the correlations between the fractal dimensions and the contents of the rest grain size are different. In generally, the more the content of clay is, the larger the fractal dimension of grain size is. (4) Because of the different situation of the two soils with different texture during the deflation process, correspondingly the fractal dimensions of grain size had different process of variation with the different wind speed and time.

Abstract:The watershed-subwatershed-hydrological response units discretization scheme were designed in the study area of Lianshui basin, Xingguo County, Jiangxi Province. Supported by RS and GIS. The method of distributed hydrological modeling based on raster Digital Elevation Models (DEM) was applied to generate basin network, to divide subwatershed and generate basin boundary automatically. The subwatershed discretization divides the watershed into subwatersheds based on the topographic features of watershed, and each subwatershed can be farther portioned into multiple hydrologic response units (HRUs) which are unique soil/land use combinations within the subwatershed and modeled through statistical spatial overlay analysis. At last 62 sub-basins and 399 hydrological response units were produced in the study area and spatial discretization of the basin were successfully realized. A series of technological problems such as the accurate generation of basin network in plate area and error correction of basin boundary were solved in the research process.

Abstract:Soil salinization is one of primary environmental problems, which faces the sustainable development in Liaohe River Delta. On the base of field survey and GPS location and soil analysis, soil salinization levels and distribution are investigated. In general, except salterns and tidal flats and bare lands between reed wetlands, soil salinizaiton level belongs to light salinization with sulfate type and chloride-sulfate type in Liaohe River Delta. The different land use type has the different influences on soil salinizaiton, paddy lands is slightly salinized. It is a good measure to plant paddy rice for improving sal-taffected soils. Although reed lands is only moderately salinized, bare lands between reed wetlands is strongly salinized. The reason is maybe because of local relief, but the irrigated water needs our more attentions. There are many scholars who used multivariable statistical analysis methods to evaluate soil salinizaiton status. Principal component analysis (PCA) is one better method used. But PCA can only be used to analyze the relationships among variables, not evaluate the relationships among variables and samples. As a result, physical meanings of principal component variables aren't distinct. Correspondence analysis (CA) overcomes this demerit. It can analyze variables (salt components) and soil samples in the common principal component space. Therefore CA method is used to deal with the sample data of Liaohe River Delta. As a result, the samples with different soil salinization level are classified clearly.

Abstract:The rock desertification in karst mountains is a kind of land degradation processes correlated with vulnerable eco-geology background and human activities. This paper chooses the typical karst mountains in Chongqing as an example to discuss the impact of different land use patterns on mechanical composition of soil, waterstable aggregates, soil organic matter, the compositions of soil seed banks and bio-diversity of karst ecosystem. The results show that the surface soil layer sandification is more evident after the reclamation, the more intensive land utilization, the more serious the destruction on soil aggregate structure. The soils of woodland and grassland systems have not only a superior soil water retention property but also a soil wate-rsupplying capacity than the soils with intense land utilization, and the soil organic matter is impressed by land using intensity distinctly. The amount of seeds of xylophyta species decreases with the increase in strength of land use, while the amount of seeds of herbaceous species increase, and most are farmland weeds. The changes of land use patterns have the dominant influence on secondary vegetation and their soil seed banks.

Abstract:On basis of achievements of related researches, this paper studies regional ecological safety systematically from the angle of theory, technology and methodology, practical application, etc. The study covers mainly: (1) set-up of a theoretic framework for assessment of regional ecological safety, which is of explorative significance theoretically, and can be used in practice as a theoretic basis for assessment of ecological safety and a methodological basis for management of ecological environment;(2) with the application of model's and remote sensing technology, realization of extraction of information of multi-characteristic type factors and the transformation from pixellevel micro-assessment value to small basin-level meso-assessment results in as sessing regional ecological safety;(3) the assessment results. by GIS technology though mapping, expressing objectively spatial characteristics of the assessment and ensuring practicality of the research findings.

Abstract:This study was carried out to examine the changes of soil physical and chemical properties and their spatial he-t erogeneity on the rainfed farmland of Horqin Sandy Land in the desertification process using methods of classical stat istics and geostatistics. Sixty soil samples of 0~10 cm layer were taken on the 300 m×90 m scale. The data were analyzed geostatist ically to determine the degree and nature of spatial heterogeneity. The results showed that soil part icle size distribution develop towards being coarse, soil waterholding capacity and porosity distribution deteriorated, and soil organic C and N, P nutrients depleted in the desertification process. The variability of soil parameters increased and the coefficient of variation ranged from 5.9% (bulk density) to 50.7% (organic carbon). Geostatistical analysis revealed that there are clearly regular changes in the pattern of distribution and high degree of spat ial variability in soil properties in the desertification of the farmland. Semivariograms and its model well reflected the degree and spatial scale of the development of desertification. In the studied area, the strip of land, where desertification developed inside the edges of the farmland along the longitudinal direction was about 100 m wide. There were close relationships between soil properties and between semivariograms of soil properties, except for pH. Desertification had very significant effect on soil organic carbon and nutrients, whereas, its effect on soil pH was relatively small.

Abstract:Soil hydraulic properties are the key information required in quantitatively modeling water flow and solute transport in the vadose zone, which can be predicted using pore scale network models. However, some important parameters in network model, e. g., pore-size distribution and pore geometry, are often assigned arbitrarily. Thus, the resulted network model cannot fully reflect the pore structure within a real soil. In the present study, a morphologically based network model is employed to more accurately characterize the pore structure, which provides the physical basis for predicting soil hydraulic propert ies. The pore-size distribution and pore connect ivity are directly measured on digital images of sequential sample sections based on mathematical morphology technique, and then integrated into the construction of network model. In theory, the morphologically based network model resembles the measured characteristics of pore structure, and should produce much better results for soil hydraulic properties. The advantages and disadvantages are then analyzed through a case study with samples collected at Fengqiu Experimental Station, Chinese Academy of Sciences.

Abstract:The spatial and temporal variability of soil properties limits the determination of soil physical parameters in situ and in a dynamic way. In this paper the technique of Thermo-Time Domain Reflectometry (Thermo-TDR) is introduced to make measurements of a wide range of soil physical properties. We outline the theories of TDR technique for water content and electrical conductivity measurement, and heat-pulse technique for determination of volumetric heat capacity, thermal conductivity, and thermal diffusivity. Furthermore, the parameters of soil bulk density, air-filled porosity, and degree of saturation are derived from the theoretical relationship between heat capacity, bulk density, and water content.

Abstract:Potexperiments were conducted in greenhouse on effects of regulatory measures including fertilization, irrigation, chemical soil amendment on distribution of soil salt and ionic uptake by crop. The results showed that fertilization increased elec tric conduct ivity of the surface soil. On the whole, electric conductivity of the surface soil in the treatment with high application rate of fertilizer was higher. Irrigation decreased electric conductivity of the surface soil layer. In the treatment with soil amendment CaSO₄ electric conductivity of the surface soil layer increased at the early stage, but came back again at the middle and later stages. Fertilization and irrigation improved the growing environment for barley and enhanced its salt resistance. When the total quantity of irrigation was maintained at 375 mm, the treatment of irrigation once every three days was superior to the treatment of irrigation once every two days in reducing salt concentration and restraining soil alkalinization. Na⁺ content in barley stem was higher than that in leaves demonstrating the function of barley retaining Na⁺ in the stem thus mitigating Na⁺ damage to the leaves. Cl^- content in barley s leaves and stems was higher than K⁺ and Na⁺ content, suggesting that more Cl^- was transported through roots to the above ground part. Modifier showed the good result of increasing K⁺ content and decreasing Na⁺ content in crop. The soil amendment showed positive effect in increasing K uptake, decreasing Na⁺ content in the plant and alleviating stress of the plant from saltions.

Abstract:A promising method for removing heavy metals from contaminated soil is phytoremediation. Heavy metal cations are strongly adsorbed onto the negatively charged soil part icles, which limits the development of phytoremediation. To enhance metal solubility and bioavailability, some natural or synthetic chelators (e. g. organic acids and EDTA) and inorganic acids have been used. In this study organic chelators such as Citric acid, Oxalic acid, Tartaric acid, Malic acid and their salts, EDTA and Nitric acid solutions for soil metal activation were used. The results showed that the trends of Cu, Zn and Pb released by the organic acids were: Citric acid> Oxalic acid> Tartaric acid> Malic acid for Cu, Citric acid> Malic acid> Oxalic acid > Tartaric acid for Zn and Citric acid> Tartaric acid> Malic acid> Oxalic acid for Pb. The organic sodium salts including Citrate, Tartarate and Oxalate had lower release capacity, but synthet ic chelator EDTA had higher release capacity, and the releasing trends of Cu and Zn by the organic salts were EDTA> Citrate> Oxalate> Tartarate, but for Pb, the order was EDTA> Citrate> Tartarate> Oxalate. 1.0 mol L^-1 and 0.1 mol L^-1 HNO₃ had the highest release capacity, which had significant difference from that of 0.01 mol L^-1 HNO₃. Considering their application to enhancement phytoremediation, EDTA and Citric acid with higher release capacity would have more promising potential in term of protection of soil quality.

Abstract:A new bioreactor was designed to study the effect of aeration on biodegradation of phenanthrene in soil. The phenanthrene mixed previously with a little soil sample was added to the paddy soil sample in the reactor to make a phenanthrene concentration of 200 mg kg^-1. The sample was stirred frequently and allowed to equilibrate for two weeks. Six aeration rates were used in this experiment: 0, 0.02, 0.04, 0.06, 0.08 and 0.10 ³h^-1. Bioreactors were incubated at 25 and water content was adjusted to 60% of the water holding capacity (WHC). Changes of phenanthrene degradation rate, number of soil microbes, act ivity of polyphenol oxidase and soil pH were measured during the 60 day incubation. Results showed that aeration at 0.08 ³h^-1 had the highest phenanthrene degradation rate (72.6%). Compared to the control, the number of bacteria and fungi were significantly higher than that of the control. Aeration at 0.08 ³h^-1 also had the highest activity of polyphenol oxidase in soil. At this aeration rate, accumulation of acidic matter in soil was avoided and consequently soil pH remained constant which favored biodegradation of phenanthrene in soil. The high phenanthrene degradation rate achieved in the present study (when soil was aer ated at 0.08 m³h^-1) can be attributed to the increase in the quantit ies of bacteria and fungi in soil, the rise in the activity of polyphenol oxidase and rather stable soil pH. The new bioreactor can be further developed and used ex situ for rapid and efficient removal of organic pollutants in solid phase of soil.

Abstract:By the nitrogen isotope method and investigation of the land use in the study area, twenty-one wells were sampled to identify the groundwater quality in urban area, Hangzhou City. The result showed that nitrate pollution of the groundwater was serious. The groundwater fell into the water category of Grade Ⅲ in terms of quality and was not potable. There was a high frequency of the samples (40.5% of the total) with nitrate above WHO's standards of N 10 mg L^-1 for NO₃-N. Areas different in land use areas were also different in nitrate concentrations (ranging between N 0.04~34.41 mg L^-1) and δ¹⁵N NO₃ values (between 7.8‰~35.5‰) of the groundwater. At the same time the nitrogen isotope method to investigate nitrate sources: in residential areas D15 N NO₃ was 10.4‰~22.0‰, and in agricultural area 17.5‰~19.5‰. Domestic sewage was the major nitrate source to the shallow groundwater in the urban area, septic tank still existing in the residential, settings the point sources of nitrate, and manure application in the agricultural areas, the non-point sources of NO₃-N sources pollution.

Abstract:The results on exchange-adsorption between aluminium and manganous ion in red soils were shown: These two ions expressed both chemical behaviours according to the universal rules of ion exchange and quite distinct characteristics of nonequivalent exchange. Nonequivalent exchange and its nonelectrical adsorption between aluminium and manganousion resulted from their hydrolysis nature, which were influenced by property of solid surface, relative exchange power of ion pair and ion amount added. The parameters concerned k, r, 1/n, K and ΔF were also explained. In view of ΔF, the processes which were spontaneous and irreversible towards stable state for exchange of manganous ion by aluminiun and adsorption of aluminium by red soil were demonstrated in thermodynamics.

Abstract:Ammonia volatilization was assessed with a nondisturbing micrometeorological technique after urea application in three different periods in paddy fields (Gleyi stagnic Anthrosol) of the Taihu Lake region. And some factors (such as climate, NH₄⁺-N concentration in floodwater, et al.) influencing the ammonia loss were also studied. The results indicated that the ammonia volatilization loss from the applied urea in the paddy fields varied between 18.6% and 38.7% of the total N applied each time. The peak of ammonia loss occurred within the first week after the application, amounting to 80.7%~94.3% of the total ammonia loss in each period. The highest ammonia volatilization flux from the paddy fields occurred within the first 24~72 hours after the application of basal fertilizer, tillering fertilizer and ear bearing fertilizer, being N 7.49, 11.17, and 5.52 kg hm^-2d^-1, respectively in Treatment HN and N 3.01, 6.79, and 1.72 kg hm^-12 d^-1 in Treatment LN. The ammonia loss from the tillering fertilizer was the highest and from the earbearing fertilizer was the lowest. Factors influencing ammonia volatilization loss varied in effect in different rice growing stages. Significantly positive correlationship was observed between NH₃ loss and NH₄⁺-N concentration in the surface water in the paddy fields in all the three fertilization perio.

Abstract:Nitrogen fertilizer is a potential contaminant of ground water. The purpose of this study was to determine influ ence of rate and timing of N fertilizer application on N movement in the soil during the crop growing season. Wheat and maize were grown alternately at Yangling, Shaanxi Province from Oct., 1994 to Oct., 1996. An experiment was conducted on effect of N application rate on N movement in cumulic cinnamon soil using urea with four rates that ranged from N 130~520 kg hm^-2 a^-1 and an experiment on effect of timing of N application on the same soil with three rates and four timings from Oct., 1994 to Oct., 1995. The two experiments were laid out in a randomized complete block with three replications. After each crop harvest, the soil was sampled to a depth of 400 cm and analyzed for nitrate nitrogen. Nitrogen rate had no influence on nitrate N movement in the soil after two years, but NO₃^--N had moved down beyond 200 cm in treatments with N rate higher than 130 kg hm^-2 a^-1. N rate increased NO₃^--N accumulation in the soil. The total recovery of N ranged from 62% to 82.7%, higher with wheat than with maize. Timing of application did not influence N fertilizer movement and N recovery, either. It was found that for irrigated wheat-maize rotation system in the region, most of the N recovered came from the top 200 cm of soil, regardless of N fertilizer practices.

Abstract:A field plot experiment with five P application rates in 4 replications was conducted on the Percogenic paddy soil in the Taihu Lake Region (TLR) under wheat-rice rotation in the year 2001 to 2002, in order to estimate the total phosphorus (TP) lost via drainage flow in wheat season and runoff flow in rice season and to figure out various parts of P loaded by both runoff and drainage flows. Results indicated that the highest P lost via runoff and drainage flow was of 0.75 kg hm^-2, which is less than 0.1% of P applied. However, the concentration of dissolved P in both runoff and drainage flow were higher than 0.02 mg L^-1 (the threshold concentration of P for inland water eutrophication). The result suggested that continuous P application with rate higher than the P demand by crops, certainly increase the risk of water eutrophication. Total P loaded by runoff and drainage flow can be partitioned as part iculate P (PP), representing more than 60% of the TP, and dissolved phosphorus (DP), less than 40%. Among them dissolved organic phosphorus (DOP) was 52.0%~76.2% in all treatments except for the highest P rate applied. Therefore, the amount and the contribution of DP in the runoff and drainage flow have been underestimated, because usually only dissolved inorganic phosphorus (DIP) is measured while DOP be discharged. The concentration of DOP in the runoff and drainage flow did not increase along with increasing P application rates in this experiment. It indicates that the source of DOP is mainly the interior soil organic P dissolved by the runoff and drainage water.

Abstract:Effects of potassium (K) on root nutrimental ecology of winter wheat were studied on the National Purple Soil Fertility and Fertilizer Efficiency Monitored Base. The results showed that K application obviously increased K concentration in root, root length, root surface area, root activity, root dry weight, the amount of root in 40~100 cm soil layer and the ratio of root/ shoot. Significant correlation was found between the grain yield of winter wheat and root activity, root length, root surface area, root dry weight, root quantity in deeper soil layer. The correlation coefficients were 0.926^**, 0.865, 0.846,0.893^**, 0.996^**, respectively. These results suggested that the improvement of root nutrimental ecology had a positive effect on the grain yield of winter wheat.

Abstract:Effects of yeast extract, glucose, peptone, soil extract and metal ions Ca²⁺, Mg²⁺, Fe²⁺, Fe³⁺, Al³⁺, Mn²⁺, Co²⁺, Zn²⁺, Li⁺, Cu⁺, Cu²⁺, Ba²⁺, Ni²⁺ on degradation of p-nitrophenol(PNP) by DLL-E4 (Pseudomonas putida) were studied. The results show that addition of a proper amount of yeast extract, glucose and peptone could promote the degradation of PNP by DLL-E4, but the addition of soil extract could not. All the metal ions, except Li⁺ and 0.1mmol Fe³⁺ could affect removal of PNP by this strain. The effects of Ca²⁺, Mg²⁺ and Mn²⁺ were low, the effects of Fe³⁺, Fe²⁺, Al³⁺, Ba²⁺ and Zn²⁺ were high when in high concentration, whereas the effects of Co²⁺, Cu²⁺, Cu⁺ and Ni²⁺ were high, too, even in residual concentration.

Abstract:土壤有机碳库(Soilorganic carbon pool)是陆地碳库的主要组成部分,在陆地碳循环研究中有着重要的作用.据估计,全球大约有1500Gt碳是以有机质形态存在于土壤中^[1],因此,土壤有机碳库量的微小变化,都会对大气温室气体浓度及全球气候产生相当大的影响.另一方面,土壤有机碳含量与土壤质量和农业生产力密切相关,不合理的农业管理措施和土地利用方式必然对土壤质量和农业可持续发展产生不利影响,破坏土壤的理化及生物学性状,破坏土壤与大气CO₂之间的动态平衡.

Abstract:三峡库区农业经济处于半封闭、落后的状态,过度垦殖、单一经营,已导致生态环境方面的巨大破坏,水土流失严重,在三峡工程兴建和移民过程中,因地制宜,全面规划,发展养殖业和经济作物,重建淹没的柑橘带,建立多种经营的生态农业体系和高经济价值的特色产品将是发挥三峡工程综合效益的有效举措^[1].三峡库区农业生态与环境监测是国务院三峡委员会对三峡工程建设环境影响研究的一个子系统,主要研究三峡库区建库对农业生态环境质量影响程度.区域土壤环境质量好坏直接影响到各种农副产品的质量^[2].本文对三峡库区紫色土、水稻土和黄壤三种主要土壤类型的重金属含量进行了分析、比较研究,为区域农业规划提供科学的土壤质量基础数据.

Abstract:量热法对吸附热的测定可直接了解多种反应的特性变化情况.用专门的微量热计已测定了某些摩尔反应焓^[1],土壤胶体在吸附重金属离子时的能量变化^[2],生化反应的米氏常数,反应速率常数,并可对酶-底物过渡态结构进行论证^[1].用热电偶方法可测定钠蒙脱,钙蒙脱的悬浮液对尿素、苯酚、乙酸根阴离子等有机物的吸附热效应,并通过吸附等温线和吸附热曲线之间的关系,推断出可能的吸附机理^[13].利用恒温套量热器测定了B(OH)₄^-与多羟基化合物的反应焓^[4].新近采用过的双温度计法,是一种类似氧弹计在绝热条件下测定体系温度变化的方法^[5].

Abstract:土壤中的腐殖物质大多数是同无机成分相结合以复合体形式存在,大部分不溶于水.为了研究腐殖物质的本质和特征,需要将腐殖物质同无机成分分离开来.目前最常用的提取剂是NaOH和Na₄P₂O₇或其混合液.含强碱的提取剂虽具有提取效率高等优点,但也存在提取过程中腐殖物质被氧化变性^[1],以及一部分胡敏酸因被分解而造成低分子化^[2]的现象.山本等^[3]发现利用NaOH提取的腐殖物质在加热至沸腾后胡敏酸量减少,黑色化程度(E600)上升.非离子性有机溶剂二甲基亚砜(DMSO)在酸性条件下可溶解很多种天然高分子有机物质.土壤中的腐殖物质也能被溶解.

Abstract:土壤质量是土壤特性的综合反映,也是揭示土壤条件动态的最敏感的指标^[1],因而能体现自然因素及人类活动对土壤的影响.研究人类活动影响下的土壤质量变化,不仅可以为探讨土壤环境的变化趋势提供一种理论方法,而且可以阐明人类活动对土壤环境的影响方向.因而,土壤质量一直是土壤学领域中的研究热点.地统计学能够对研究对象的空间格局进行检验、模拟和估计.空间局部内插法提供了最小方差的无偏估计,在生态学中得到了广泛的应用^[2].考虑到土壤属性空间上的渐变性与一定范围内属性信息的空间相关性,因而地统计学的方法用于研究土壤的时空变异特征,是最为有效的方法之一^[3,4].

Abstract:甲磺隆是国内外现阶段广泛使用的一种新型除草剂,用量少、生物活性高、对人畜低毒等是它的显著特点.已有研究者就该种除草剂在正常用量下对土壤呼吸作用^[1]、硝化作用^[2]、土壤酶活性^[3]、土壤微生物生物量^[4]等进行了研究.相比较而言,甲磺隆除草剂污染区土壤微生物多样性变化的研究鲜见报道.BIOLOG碳素利用法是一种较为先进的研究不同环境下的土壤微生物群落结构和多样性的方法^[5].该方法已广泛应用于鉴定和分析不同体系中的土壤微生物群落结构^[5]、同一土壤不同作物栽培条件下的微生物群落结构^[6]、重金属污染土壤微生物群落结构分析^[7]等方面.

Abstract:土壤微生物与土壤自净作用密切相关,它直接参与土壤动植物残体、外来有机物质和其它有毒有害有机化合物的降解过程.然而,这些有机物质的存在也同样会影响土壤微生物的活性及其多样性^[1].土壤生物学性质能敏感地反映出土壤质量和健康的变化,是土壤质量评价不可缺少的指标^[2].土壤生物极易受土壤环境因子的影响,如土壤水分、温度的季节变化、作物根茬和根际产物(如根分泌物、粘胶物质、脱落细胞等)以及有机无机肥料的施用均会对土壤生物产生较大的影响.