Abstract:The advance of quantitative remote sensing for monitoring annual soil losses and its application in Taihu-Lake catchments was introduced in this paper.The form of the model for monitoring soil losses in the method is as good as the RUSLE.The application results of modified method include not only the total losses of annual soil erosion,statistic data of different grades and soil erosion map and forecasting map of soil conservation intensity in 1996,1997,1999,but also monitoring system in long-term.The monitoring results of Taihu-Lake catchments application again showed that the QRSM is more accurate,more rapid and more economic than original QRSM in the applications Shandong province and Quanzhou city of Fujian province.The variance character of time,space of soil annual losses and the application spectrum of monitoring results,and the non-point source pollution of water quality were discussed according to monitoring results in Taihu-Lake catchments.With the work of monitoring soil losses in our country,the QRSM will be widely used in soil erosion region and shows its economic,ecological and social benefit.

Abstract:This paper deals mainly with soil-forming factors and characters of the mountains in South Anhui. According to the "Chinese Soil Taxonomy(Revised proposal)",and the "Chinese Soil Taxonomy(theory-method-practice)",diagnostic horizons,diagnostic characteristics and attribution in soil taxonomic classification of nineteen soil profiles distributed vertically in the mountain regions.Results showed that Udic Luvisols(Udic Cambisols),perudic Luvisols(perudic Cambisols)and orthic Entisols(perudic Cambisols)were distributed in sequence from foot to top.Comparisons were also made with the soils in the mountain regions in Jiangxi and Fujian in terms of attribution in the Chinese Soil Taxonomy and between attribution of the soils in different soil classification systems.

Abstract:Holoence polycyclic soils were discovered on the Zhouyan tabeland.A typical loess profile is observed by field and soil micromorphology,as well as magnetic susceptibility,grain-size analysis and trace elements.Argillic horizons were identified in the soil and calcification was observed in the loess layer in the profile.It suggests that the Holoence palaeosols S₀² and S₀¹ were formed in warm-wet forest environment. Because of the deposition of a layer(L_x)during the aridity interval between 6 000 and 5 000 aB.P.,the palaeosols S₀,normally associated with the Holoence Megathermal period,is thus separated into two distinct soils,namely palaeosols S₀² and S₀¹.The conclusion is confirmed by the magnetic susceptibility, grain-size and trace elements in the profile.It indicates that the lower soil(S₀²)was formed in the warm-wetest phase in the Holoence in the Guanzhong basin,with the strongest pedogensis,between 8 500 and 6 000 aB.P.The upper soil(S₀¹)was developed in another warm-wet phase when the rainfall was probably lowered slightly between 5 000 and 3 100 aB.P.It has been a relative aridity period during the last 3 100 years,with accelerated aeolia dust deposit.A layer of 40~60 cm thick loess has been accumulated on the Zhouyuan tableland and thus the siol complex has been buried and becomes palaeosol of the Holoence.

Abstract:In the past forty years,some environmental factors closely related with evapotranspiration in North Henan Province have greatly changed.For example,evaporation from water surface decreased,relative humidity near to the ground surface increased,sunshine hours reduced and wind speed decreased.Similar to the problems of seasonal running dry of Yellow River and ever-lowering ground water table in the region,the change of these environmental factors might partly reflect the change of environmental quality ecologically.Our results showed that the change was mainly caused by humane activities,such as marked increase of irrigation areas and improvement of low-yield farmland in large area.Great attention should be paid to the problems resulted from the change of these environmental factors.

Abstract:The division of regional land-use structure in the coastal area of low mountains and hills of southeastern China was studied in this paper by the quantified structure analysis method of landscape ecology,according to the square and ratio of second class land types of the detailed land-use investigation and a case study in Wenzhou City.The results showed:(1)the division of regional land-use structure can be revealed well by the above-mentioned method,and those results can show the regional structural differences of natural condition,natural resources and socio-economical development in the study area;(2)the regional change of land-use structure in the study area saw the following regular patterns:the structural diversity and composed types of land-use decrease by degrees from coastal area to inland area,from the plain area to the mountain area and from nearby suburbs to far suburbs,but the centrality of land-use structure is on the contrary,and composed types of land-use are related with the features of regional economical activities;(3)the regional differences of land-use structure in the study area are influenced strongly by the geographical place,geomorphologic situation,location advantage,level of economical development and other factors.

Abstract:Soil hydraulic properties,including soil water characteristic curve and the unsaturated hydraulic conductivity function,are the key information necessary for study of water and solute movement in the vadose zone.Unfortunately,the great spatial variability and the complexity of soil make direct measurement of these properties costly,time consuming and error-prone.For a large scale application,this may be even infeasible.Hence,indirect methods,which relate more easily measured soil physical properties to hydraulic properties,have been considered valuable alternatives.In the present study,three fractal models, i.e.,Tyler-Wheatcraft,Rieu-Sposito and Brooks-Corey models are used to figure out soil water characteristic curve based on part icle size distribution data.Applicability of these models is evaluated based on the particle-size distribution and soil water characteristic curves of 554 soil samples cited from the Unsaturated Soil Hydraulic Database,UNSODA and other publications.Soil textures of these samples cover the range from sand to heavy clay,and each sample has more than six pairs of pressure-water content measurements.Goodness-of-fit between measured and est imated volumetric water content is expressed in terms of root mean squared error.Results show that,the predictive accuracy of Brooks-Corey model is higher than that of the other two fractal models.In addition,it is suggested that models should be applied to soils texture specifically.In other words,for medium- and coarse-textured soils,Brooks-Corey model is preferable,while Rieu-Sposito model is much more suitable for fine-textured soils.And Tyler-Wheatcraft model is in between the two aforementioned models in terms of estimation error.Tyler-Wheatcraft model can be used for both coarse- and medium-textured soils.

Abstract:In this paper,we have studied the fluvo-aqic and eolian sandy soil in Fengqiu County,Huanghuaihai plain area and tried to find the practical and feasible ways to solve problems of the parameter of soil hydraulic properties.Based on a great many of fundamental soil physical properties and soil water-retention data in Fengqiu county,pedo-transfer function models of van Genuchten model parameters(θ_r,θ_s,a, n)were established by the use of multivariate stepwise regression analysis respectively and verified by means of statistics analysis and numerical simulation.The results showed that parameters of van Genuchten model had some linear correlation with basic soil physical properties.The fitted effect of parameter est imation model of van Genuchten model on clay soil was very well but the effect on sandy soil was not good because of big errors.

Abstract:TDR soil moisture instrument(model ET-FOM/mts,made in Poland)was calibrated for two types of soil of different texture in Fengqiu region under different treatments of temperature and bulk density.The result show that the relationship between the square root value of dielectrical constant of soil and soil water content in volumatric basis can be well described by linear equations of which the correlation coefficient are equal to or greater than 0.997.Regression errors of the calibration curves range from 0.002 to 0.027 cm³ cm^-3,and sandy loam soil shows the smallest error at low temperature(16℃),while the biggest error occurs when loamy clay soil is measured at high temperature(26℃).

Abstract:A one-year indoor soil column simulation experiment was conducted to study salt dynamics in soil (0~40 cm layer)of silt loam with different groundwater conditions.The obtained results show that electric conduct ivity of the soil(EC₀)is in positive correlation to groundwater salinity under the condition of groundwater table ranging from 85 cm to 105 cm.When the groundwater table is at 155 cm,salt accumulation of the soil columns in 0~40 cm layer is much less intensive and varies slightly in intensity regardless of the difference in groundwater salinity.In order to evaluate the effect of groundwater table and salinity on EC₀,a statistical model was built.Deeper analysis of the law of the dynamics of soil electric conductivity has eventually led to the set-up of models about EC₀ dynamics(after mineral groundwater influenced EC₀ evidently).

Abstract:This paper reviews previous methods for measuring the microbial biomass P in soil,with comments on their problems and limitations in the use for different soil types,and described main procedures involved in the measurement.A study was carried out to validate the methods for upland soils in China.Results show that for the 45 soils used,the flush of inorganic P(P_i)extracted in 0.5 mol L^-1 NaHCO₃ (pH8.5) at a soil solution ratio of 1:20 following gaseous chloroform-fumigation,as proposed by Brookes et al.^[4], provided a better indication of the amount of the biomass P than that extracted at a lower soil solution ratio (1:4),or in 0.03 mol L^-1 NH4F-0.025 mol L^-1 HCl at both the ratios(1:4 and 1:20).In most of the soils,the size of the flush of P_i was not significantly different from that of the flush of total P extracted (P_t),suggesting that the measurement of P_t was not necessary.

Abstract:Spat ial variability and regionalized management technology of soil nutrients in a grain crop region with an area of 470 km² was studied using geo-statistics.The results showed that the grain crop region was widely deficient in N,P,K,Mn and Zn.Variation of the soil nutrients differed remarkably.The maximum correlative distance of major soil N,P,K,Mn and Zn in content was 27.1,19.7,27.1,14.4 and 26.4 km,respectively.It revealed that their variation in content developed in large block scale,which is useful to regionalized management of soil nutrients.There was a notable tendency of soil readily available nutrients in spatial distribution in the grain crop region.The grain crop region could be regionalized into 2 to 3 management units,and each unit consisted of connected fields.The number of management units in the grain crop region were 2 for N,3 for P,3 for K,3 for Mn,2 for Zn.With regionalized balance fertilization technology on wheat and corn,yield increased by 10.9% to 13.1% and 14.3% to 21.7%,respectively,economic profit by 590 to 747 and 724 to 1343 RMB Yuan hm^-2.

Abstract:This paper puts forward a new kinetic model of potassium based on Lotka-Volterre model in ecology. A potculture experiment was conducted showing that with the model,dynamic trends could be simulated of readily available potassium and slowly available potassium of soil in the growing period of peanut.The test of potassium absorption indicated that the change in K absorption in different growing periods of peanut accorded with the Logistic model.From the above two models,constants of the maximum release rates for mineral K(Kmm),slowly-available K(Krm)and rapidly available K(Kam)could be got.Correlation analyses showed that the relationship was obvious of Kam with K absorption of the current crop,its biomass yield and its peanut yield,and between Krm and K absorption by the current crop.Therefore, Kam and Krm could be used as index of potassium release rates in soil.

Abstract:Effects of land application of dredged sediment from the Grand Canal(Hangzhou section)on the distribution of phosphorus in soil layers were studied by soil column leaching experiments.The results showed that application of dredged sediment did not significantly increase phosphorus concentration in the soil column leachate.Dry-wet alternative treatment has strong effect on the release of available phosphorus from dredged sediment to subjacent soil layer.After application of dredged sediment,contents of Olsen-P in the upper 15 cm soil layers were markedly higher than that of the control column,but in deeper soil layers, increasing in Olsen-P was insignificant.The increase in Olsen-P was partly due to release of organic acid from dredged sediment,which increased soil organic carbon content and decreased soil pH in the whole soil column.The more dredged sediment was applied,the longer effect on soil and ground water may last.

Abstract:The strength of Cu²⁺,Pb²⁺ adsorbed by the tested soil colloids could be expressed by pH₅₀ value.The strength of Cu²⁺,Pb²⁺ adsorbed was in sequence of old manured loessal soil>dark cultivated loessal soil>yellow loessal soil>yellow cinamon soil.Cu²⁺,Pb²⁺ adsorption of the tested soil colloids mainly include specific adsorption,and n value was regarded as characteristic value of specific and electrostatic adsorption proportion.The proportion between specific and electrostatic adsorption was related to pH.The percentage of Cu²⁺,Pb²⁺ specific adsorption by the tested soil colloids showed the trend of yellow cinamon soil>old manured loessal soil>dark cultivated loessal soil>yellow loessal soil.At lower pH,adsorbed mechanism was mainly controlled by hydrolysis-complex reaction;at higher pH,it was controlled by hydrolysis-complex and precipitating adsorption.The sequence of Cu²⁺,Pb²⁺ intrinsic complex constant of different soil colloids was consistent in adsorbed strength.If the interaction of metal ions was considered,the adsorption of soil colloids to metal ion could be described through BDM equation. value was expressed as Cu²⁺,Pb²⁺ adsorbed strength by soil colloid,the larger the negative value was,the larger the specific adsorbed strength was.The negative value of in different soil colloids was consistent with the sequence of Cu²⁺,Pb²⁺ intrinsic complex constant and permanent charge density.

Abstract:The effects of several organic substances,including natural humic acid and fulvic acid,artificial chelating agents EDTA and DTPA,and four simple organic acids on the solubility and adsorption-desorption behaviors of purplish soil for cadmium were studied.Results showed that all the organic substances tested significantly promoted the solubility of cadmium from the purplish soil,with a magnitude sequence of EDTA≥DTPA>citric acid>humic acid>oxalic acid>fulvic acid>tartaric acid≥salicylic acid. These effects were attributed to their comprehensive influences on the adsorption and desorption of the soil for cadmium.Organic substances remarkably inhibited the adsorption of purplish soil for cadmium.The sequence of the inhibiting effects was as same as their influences on cadmium dissolubility.Desorption characteristics of absorbed cadmium were also altered by these organic substances.At the presence of organic substances the adsorption kinetics of purplish soil for cadmium was best fitted by the double-constant equation,and the curves of isothermal adsorption was best described by Freundlich equation.The adsorption constant n in Freundlich equation was well correlated with the dissolving rate of cadmium.

Abstract:UV-VIS spectroscopy and molecular size distribution of water soluble organic carbon(WSOC)of 4 soil samples collected from the eastern part of China were determined.Correlation between relative molicular size of WSOC and ratio of absorbance at 250 nm and 365 nm(E2/E3)together with UV absorbanc intensity per unit carbon at 240 nm(E/TOC)were calculated.Also,same analyses were performed on fulvic acids extracted from part of the soil samples.It was found that there was a significant negtive correlationship between E2/E3 and molecular size of WSOC,while a significant positive correlationship existe between E/TOC and molecular size of WSOC,which means that E2/E3 and E/TOC could be used t study molecular size distribution of WSOC.But no similar relationships were found for fulvic acids.Th reason for it needs to investigate further.It was also found that E/TOC showed a decreasing tendency from north to south and east to west in the studied area.Climate,mainly the temperature and precipation wa thought to play an important role on spatial variation of UV-VIS of WSOC.

Abstract:A pyrethroids degrading strain qw₅ was isolated from activated sludge.The strain qw₅ was preliminarily identified as Bacillius Licheniformis.The optimum temperture and pH for the aerobic degradation of pyrethroids by qw₅ were 30 and pH7~8.The strain was able to degrade Fenvalerate,Cypermethrin and Deltamethrin by approximately 53.8%,41.2% and 61.7% respect ively within five days.Benaldehyde, 3-phenoxy,the metabolite of Fenvalerate was detected by mass spectrum.The strain was not pathogenic to white mice and sensitive to some commonly used antibiotics.The results from pot and field experiments showed that the strain had obvious effect on the removal of pyrethroids residual in green vegetable.

Abstract:The translocation and degradation of benfuracarb in different soils were studied.The leaching of benfuracarb in soils was described.The vertical distribution of benfuracarb and carbofuran,a metabolic product of benfuracarb,ranged from 0 to 14 cm in soil column.The benfuracarb and carbofuran in the soil column that was lower than 14 cm.Benfuracarb and carbofuran move to lower in soil column with more precipitations.Results indicated that there was little possibility of comtaminat ing the underground water.Results showed that the half-life of benfuracarb was 6.3~8.8 d in three different soils.There were some differnces with different soils.Degradation of benfuracarb was not much more slowly under sterilization condition than that under normal condition.When soils were treated with sterilization,the half-life of benfuracarb is 6.8~10.4 d in three soils.The result suggested that chemdegradation had a greater effect than biodegradation.Within 30 d,benfuracarb was degradated fast and produced carbofuran and 3-hydroxycarbofuran.Carbofuarn are subsequenly degradated irregularly.3-hydroxycarbofuran produced in the process was little.The method based on gas chromatography and NP detector was applied in this study.

Abstract:为了满足日益增长的人口对粮食的需求,农用化学物质被广泛应用,这些物质可通过各种途径进入土壤,因此研究土壤中农用化学物质的运移、转化对于防止水环境污染、促进农用化学物质的高效、发展可持续农业有着重要的意义^[1].

Abstract:Olsen^[1]、BrayKurtz1^[2]、Mehlich3^[3]、Morgan^[4]、Vermont1^[5]和Vermont2^[5]等法是用于确定土壤有效磷含量的主要常规方法。根据土壤有效磷测定结果可为农户提供施肥建议以及预测施用磷肥或家畜粪肥后的经济效益等^[6].由于这些常规方法的广泛使用,且有大量的数据资料可供利用和参考,因而许多研究者对这些方法在环境方面的应用进行了大量的研究,表明这些方法的土壤磷测定值与土壤中或地表及地下径流中的溶解性磷或藻类有效磷含量之间通常有着良好的正相关^[7～12].

Abstract:黄土高原丘陵沟壑区,千沟万壑,人少地多,广种薄收,土地生产力低下。由于黄土结构垂直发育明显,耕层疏松,土壤粘粒性差,有机质含量低,土壤抗冲抗蚀性弱。丘陵沟壑区大多处于半干旱区,降雨量较少,严重的水土流失和水分不足已成为限制黄土丘陵沟壑区粮食生产的主导因素^[1,2].垄沟耕作作为一种水土保持复合耕作法,改变地形,拦蓄部分径流,相对增加土壤蓄水,减少土壤流失,同时有利于作物通风透光,充分发挥边行优势,且光能利用率高,提高水分利用率,达到增产目的^[1～4],已在部分地区推广和应用。

Abstract:随着污水灌溉面积的迅速扩大,污灌区土壤重金属污染问题日趋严重,其中Cd、Pb的污染问题十分突出^[1,2],了解污水灌区土壤重金属的空间分布特征是防治土壤污染、合理进行污水灌溉的重要前提。地统计学作为一门新的空间分析方法^[2],它特别适于对区域化变量空间变异特征进行定量描述,但已有的研究主要限于对土壤水分、盐分和pH等性质的估测^[3～6],对其它土壤性质特别是土壤环境中有毒有害元素的空间分布与含量预测研究较少^[7,8],而且因研究的空间尺度太小^[8]而实用性不足,有许多领域和土壤特征的空间变异研究至今仍未涉足,本研究以污灌历史较长、在我国具有代表性的太原污灌区为对象,运用地统计学的方法,研究了中尺度条件下污灌区耕层土壤Pb、Cd的统计特征和各向异性的空间分布特征。

Abstract:植物质外体是由细胞壁的纤维素和微晶体空间以及充满空气的细胞间隙组成,约占植物体积5% 的空间。很久以来,质外体被认为是无生命的,与有生命的原生质相比很少引起研究者的兴趣,直到80年代中期,由于研究技术的发展和研究的深入^[1],对质外体的认识才发生根本性的转变,认识到了其重要的生理作用。