Abstract:According to statistical data of agriculture, analysis of soil samples and fertilizer application survey from farmhouses, it was studied for fertilizer application rate, farmland nutrient balance and change of soil nutrient in Shanxi. Results of surveying from farmhouse showed that the average application rate of mineral fertilizer in Shanxi was 181.8 N kg/hm~2, 93.7 P_2O_5 kg/hm~2 and 41.9 K_2O kg/hm~2 in the year of 2000. Ratio of NPK in the mineral fertilizer input was 10.520.23. It was found that fertilizer application rate on irrigation land was more than the rate on dryland, and the rate on the vegetable and fruit tree was more than the rate on food crops and cash crops. Results of nutrient balance from three counties showed that N, P in farmlands was obviously surplus with the increasing of N, P application from 1980, and K was deficient at all time. Meanwhile, comparing with content of soil nutrients between 2000 and the second soil survey in China, the change of available P and K in soils in Shanxi , and effects of nutrient balance on soil nutrients were realized in the three counties.

Abstract:This paper mainly discussed the monthly dynamic changes of the nutrient content of root and soils nutrient in the model of Triploid populus tomentosa and Lolium multiflorum Lam in cultivating lands to forest. Based on detailed investigating forest lands,analysing samples and processing datum,the conclusions can be drawn:In the model,the number of Lolium multiflorum Lams root absorbing N element was 0.3950.408 g/kg,and it was higher than that of tree root about 0.1730.369 g/kg,so the tree was the main factor that caused the change of the living being absorbed the N element. But the absorption to efficacious P and N was just in the opposite. The number of tree roots absorption was 2.4863.486 g/kg, and that of grass root was 4.5726.092 g/kg. On the other hand,the change of content of tree roots K was relatively big,but the grass roots change was small,and soils K usually was supplied abundantly. With theCa content in the forest land increasing, the roots of Triploid populus tomentosa increased,and it was 4.6519.764 g/kg,but the grass roots absorption was just opposite. The Mg demand of tree root and grass root respectively was 10.54710.744 g/kg and 10.36510.610 g/kg. It was similar not only on the trends of seasonal variation,but also at the number of demand,so the characteristic of utilizing and absorbing should be pay attention to in applying Mg fertilizer.

Abstract:In normal conditions, dissolved P, NH_4-N and NO_3-N in the surface waters of rice fields could be diffused within 10 m, and the diffused distance increased in the order of dissolved P 15 m width could decreased significantly the concentrations of N and P in drainage. Therefore, rice fields without application of fertilizers could be used as a riparian buffer to control runoff N and P in rice production area. The mechanism of rice buffer controlling N and P runoff loss was similar to wetland.

Abstract:According to similar natural condition and different years of de-farming, this research studied nitrogen variation features of the desertification soils of different de-farming and wasteland in the western Karst region, Guizhou province. The result shows that the content of soil organic matter,total nitrogen and different forms nitrogen decreased firstly, then increased by time pasted. Based on this conclusion, and effect of heat and water in this region, the paper deduced that it is possible to restore the nitrogen fertility under natural condition.

Abstract:The correlation relationship between soil biaomass nitrogen and mineralisable nitrogen was studied with field experiment and incubation experiments. The result showed: that correlation relationship between soil biaomass nitrogen and mineralisable nitrogen had weak correlation relation under field conditions; but there was significant linear correlation relationship between soil biaomass nitrogen and mineralisable nitrogen under waterlogged incubation conditions, nitrify incubation method and Standford short-term incubation method, and the correlation coefficients were over 0.767(p<0.001, n=12). The difference of results between field experiment and incubation experiments was relative with the difference between experiment conditions. The newly soil biaomass nitrogen was easily decomposable, but the old one was stable relatively.

Abstract:Studies on water and nutrition dynamics of dry farmland were carried out in fixed positions in Sands area. There were 3 types of dry farmland in areas without shelterbelts, namely wind-eroded land(on the wind ward),wind-accumulated sand(on the leeward)and the transitional part. Wind-eroded land was the best and, wind-accumulated sand worst in moisture condition. The top soil (0~20cm) was better than the lower part (20~60 cm) in nutrition. Soil fertility was the poorest in wind- accumulated sand, and best in the transitional part. The dry farmland in sandy area had clear characteristics. The fluctuation soil moisture was smaller than that of rainfall in the year. Crops with synchronous needs for water and nutrition were of high production. The output was not greatly influenced by total N, P or K but in close correlation with organic matter, available P and K in top soil and available N in lower part.

Abstract:The interactions between different N, P, K fertilizers and super absorbent polymers(SAP) with different water absorbent rate (WAR) such as polyacry lamide, polyacrylic salt, and starch graft polymer were studied by determining WAR and amounts of absorbed and fixed fertilizers by SAP. The results showed that chemical fertilizers could obviously decrease the WARs of SAPs, and the WARs of SAPs were markedly decreased with the fertilizer concentration increased. However, different fertilizers had different affecting degrees. The effects of fertilizer on the WARs were: super phosphate > monoammonium phosphate > potassium sulfate > ammonium chloride > ammonium sulfate > potassium chloride> urea. When SAPs swelled in water, they absorbed and fixed the fertilizers dissolved in water while they absorbed water. The amounts of absorbed and fixed fertilizers differed with SAPs and fertilizer types. Up to a certain fertilizer concentration, it decreased with the WARs decreased. Polyacry lamide and polyacrylic salt graft polymer had stronger resistance to fertilizers than starch graft polymer.

Abstract:In this paper, we explored the influence of Zn stress on plant growth, nutrient content and Zn accumulation in four varieties of ryegrass (Loliurn perenne L.) by pot experiment (root bag method). The results showed that Zn (at Zn concentrations of 0~520 mg/kg in soil) stimulated the plant growth of ryegrass, RTI (root tolerance index) was more than 1.0 (0~520 mg/kg Zn~(2 ) in soil). Zn stress (260 mg/kg or 520 mg/kg Zn~(2 ) in soil) did not inhibited N, P and K absorption by plant of ryegrass. The maximum or high Zn contents in shoots and roots were found at Zn treatments of 260 mg/kg or 520 mg/kg in soil, in which the maximium or high biomass were recorded. Zn contents in plant were increased with increasing Zn concentrations in soil. Zn contents and transport rates of Taide were higher than the other varieties of ryegrass (S/R>1). The maximums of Zn contents in shoots of Taide were found by 583.9 mg/kg DW (at Zn concentrations of 1 040 mg/kg in soil).

Abstract:The influence of air resistance and soil bulk density on infiltration rate, accumulative infiltration and wetting front was analyzed, and the average water content increment during infiltration was researched.Air resistance and soil bulk density have obvious influence on infiltration rate, accumulative infiltration and wetting front: the infiltration decrease ratio(IDR) of accumulative infiltration due to soil bulk density increment was a constant, and IDR was 31.79% and 52.03% for 1.4 g/cm~3 and 1.5 g/cm~3 soil bulk density compare to 1.3 g/cm~3 soil bulk density.The infiltration decrease ratio(IDR) of wetting front due to soil bulk density increment was not a constant which was influenced by time. The infiltration decrease ratio(IDR) of accumulative infiltration and wetting front due to air resistance was not a constant which was influenced by time. The average water content increments during infiltration were 0.377, 0.341 1 and 0.313 7 for 1.3,1.4 and 1.5 g/cm~3 soil bulk density, respectively, in condition of no air resistance.

Abstract:The landscape pattern is indicator of the regional climate and many other factors, and it also has significant effect on runoff. The vegetation landscape pattern and runoff in Jinghe river basin on the Loess Plateau was studied in this paper, the result showed as follow: Average runoff and its yearly variation increased with the vegetation landscape structure turned to complex and landscape diversity enlarged. Compared with grass landscape watershed, runoff of forest and shrub watersheds was bigger and more uniform, while that of compound landscape watersheds was inferior. The landscape contagion index and dominant index related to runoff positively, while the landscape diversity index and the landscape patchiness index related to runoff negatively, and the landscape shape index did not relate to watershed runoff. The annual variation of runoff turned to uniform with the landscape patchiness index and landscape diversity index increased, and it turned to extreme with the landscape contagion index and landscape dominant index increased, and it did not relate to landscape shape index. The extreme runoff (very big or very small) of watershed decreased with the landscape diversity increasing.

Abstract:The matural sloping face of different gradient slope in the hilly region in south of Ningxia after changing sloping field were experimentally studied by means of artificial rainfall simulation. The results showed that the rainfall intensity were in inverse ratio to supplement soil conserving water, infiltration depth were reduced with the increase of gradient. The effect of artificial rainfall simulation and doubt ring method to steady infiltration rate were compared, the soil steady penetrating velocity measured by artificial rainfall was less than one measured by two loop method, and there were linear function relationship between two values. The water supplement to level trench increased with the increase of the gradient and rainfall intensity, the downfall were significant to the water supplement to level trench. The analysis of sediment yield dynamics showed that the sediment content per volume descended with time process under bigger rainfall intensity, while increased by degrees under smaller rainfall intensity. The relationship of rainfall power and soil erosion modulus accorded with the power function equation:Q=0.017 I~(2.5442)

Abstract:Quantitative simulation on soil detachment rate is the base of process-based soil erosion model development. This study was conducted to analysis hydro-dynamic mechanism of soil detachment process for original soil core in loess region under the large range of flow discharge (0.5~2.0 L/s) and slope gradient (8.8%~46.6%). The results indicated that detachment rate of disturbed soil is more greater than that of original undisturbed soil caused by the disturbance of soil structure. It is necessary to use original undisturbed soil to investigate the mechanism of soil detachment and soil erosion. Soil detachment rate increased with both flow discharge and slope gradient increasing. However, the regression equations were slightly different between each other. Soil detachment rate can be simulated with power function of flow discharge and slope gradient (R~2=0.95). Due to the influence of sediment transport and soil sample disturbance, erodibility parameter of current study was significantly different with the relative results obtained from disturbed soil samples. Therefore, it is necessary to use original soil sample to simulate soil erosion mechanism. Among three current used hydro-dynamic parameters of shear stress, unit stream power, and stream power, there was closely relationship between soil detachment rate and stream power.

Abstract:Soil column is used to study the characteristics of calcium movement in uprightness direction in Brown-soil which is in a middling rainfall condition. The result shows that with the increase of calcium which input to the soil,the availability calcium is markedness increased by 2.2%~22.4%, and theloss of the calcium is markedness heighten to 48.6%~80.4%; suitable combination of calcium and phosphorous can make the eluviate rate reduce by 31.8%,the summation of availability calcium increased by 6.0%.When the content of calcium and phosphorous is 11, it can enhance the availability calcium in soil effectually and reduce eluviate rate of calcium.

Abstract:Pit irrigation is a new method that can check soil erosion suitable for fruit tree and forest in gully and hilly. According to the specific of pit irrigation field engineering, the characteristic of runoff producing rain and sink flow in pit irrigation were analyzed. Based on this, the runoff process, initial abstraction time, runoff amount and runoff coefficient in a fruit tree control areas were analyzed and deduced; meanwhile,corresponding theoretical models were worked out; an example of models application was illustrated. This study will have an important value for design on field engineering of pit irrigation under some soil and water conservation standard condition.

Abstract:The relationships of forest interception with rainfall and canopy density have been studied by modeling.It was concluded that the forest interception of Picea crassifolia could be simulated precisely by the compound model of I=a(1-e~(-PC)) bPC which including canopy density factors. The parameter a(1.362 7)means rainfall adsorption capacity of canopy, and parameter b(0.183 5)means coefficient of evaporation of canopy regionally, all this explain the law of forest interception which composed of 3 physical courses:adsorption,soakage and evaporation. It was indicated too that the curve of forest interception with rainfall marked 3 phase such as descent quickly phase(interception rate of fall canopy density stands is more than 36.1% while rainfall is less than 25mm),descent gradually phase (interception rate is in 36.1 .4% while rainfall is in 5~25 mm)and stable phase(interception rate is less than 20.4% while rainfall is more than 25mm),which explain the relationships of interception with canopy geometry shapecharacteristics of Picea crassifolia. The mean interception rate of imperfect stands in periods of investigation is in 19.36%~23.96%,but that attend to 25.67% for perfect stands with fall canopy density. The stemflow is less than 0.1% and the mean value is less than 0.018 2% for the special geometry shape construction of canopy go against stemflow.

Abstract:Field experiments were carried out to determine effects of cereal-cereal or wheat-oilseed rotation on degradation, recovery and nutrient balance of dryland soils. Results showed that soil biomass dominated with bacteria was increased significantly by spring highland barley-spring oilseed or spring wheat-spring oilseed. The increments of organic matter, total nitrogen and total phosphorus in soil were 3.053.06 g/kg, 0.060.07 g/kg and 0.010.26 g/kg, respectively. Spring wheat-spring highland barley or spring highland barley-winter wheat rotation also was benefited to raise soil fertility. However, spring wheat continuous cropping and spring highland barley-winter wheat rotation had a positive effect on micro-organism community in soil where the amount of soil bacteria decreases significantly. There was a degradation trend for the organic matter, total N and total P in 030 cm, 3161 cm soil layers. Although K was input in soil, there was a deficiency of soil K in different rotation systems.

Abstract:Nutrient management is very important to greenhouse cropping systems. Based on the input and accumulation of soil nutrients, status of nutrient management of greenhouse cropping in China was illustrated in this paper, while the problems that irrational nutrient management resulted in, such as soil salt accumulation, proportion of nutrition elements maladjusted, vegetable quality declined and environment polluted etc., were pointed out. In addition, strategies were suggested in order to improve nutrient management of greenhouse cropping systems.

Abstract:Forest and grass ecosystem plays a very important role in converting agricultural lands to forest. This paper makes a preliminary study on grassland and dynamics of nutrient elements about three different forest-grassland pattern around the Sichuan Basin. In order to know about essence of forest and grassland ecosystem and provided theory for forest mixed with grassland.

Abstract:The evolution of salt accumulation in greenhouse soils in Liaoning province was studied in this paper.The results indicated:(1)The salt contents of greenhouse soils were much higher than those in the corresponding open field soils.The average of the salt contents in 020 cm layer of greenhouse soils was 2 685.46 mg/kg (CV=58.0%) in Shenyang and 1 274.25 mg/kg(CV=40.5%) in Beining. (2)The highest salt content was found in greenhouse soils used for about 4 years, mean salt content and EC were 1861.28mg/kg and 0.53 mS/cm,respectively. (3)Compared with neighboring open field soils,the contents of every ion were all increased a lot in the greenhouse soils and among them, NO_3~-,SO_4~(2-) and Ca~(2 ) were accumulated much more than any others.(4)The salt moving downwards to the bottom soil(80100 cm) and salt accumulating upwards to the topsoil(020 cm) were very obvious in greenhouse soils.The content of each ion was decreased accompanying with deepening profile. The accumulation of NO_3~- and its moving to the bottom soil in the greenhouse would have some bad effect on the environment.

Abstract:A field trail was conducted to determine the effects of conventional tillage(T1), conventional tillage with stubble retention(T2), no tillage(T3) and no tillage with stubble retention(T4)treatment on crop yield and soil oxdizible organic carbon within maize-wheat-soy rotation system in the western Loess Plateau. The results indicated that there was no significant tillage effect on crop yield for each six harvesting during the year 2001 to 2004. The easily oxdizied organic carbon in the 0~5 cm soil layer under no-till with stubble retention treatment increased by 2.44 g/kg significantly compared with that under conventional treatment. The most oxdizible organic carbon had significant positive correlation to soil total nitrogen and water stable aggregates. We concluded that effect of conservation tillage on crop yield was delayed to that on soil fertility change,soil oxdizible organic carbon is a one of sensitive indicator to indicate soil organic carbon change to the tillage practice.

Abstract:According to the analysis data of 173 sampling points in 1982 and 117 sampling points in 2002, the temporal-spatial variability of soil available phosphorus (SAP) of the topsoil(0~20 cm) in Chengdu Plain was expressed by spherical semi-variance model and the ordinary Kriging interpolated method. The results indicated that the average content of SAP changed from 7.1 mg/kg in 1982 to 14.3 mg/kg in 2002, with an increase of 103.40%. Influenced by the differences of agricultural management, the land use type and the soil granule contents during the past 20 years, SAP content of 75.86% of the plain area increased, respectively, which presented decreasing trend from the east to the west. The results of correlation analysis between SAP content and soil particle composition showed that, in 1982, there were highly significant negative correlation between the SAP and soil sand particle (20.02mm) content, and highly significant positive correlation between the SAP and soil clay particle(<0.002 mm), while no significant correlation between the SAP and soil silt particle(0.020.002mm). The case was different in 2002, SAP was significantly negatively correlated with soil sand particle content, and highly significantly positively correlated with soil silt particle content, while not significantly correlated with soil clay particle content.

Abstract:The experiment was carried out to evaluate effects of covering wheat straw in apple orchard and apricot orchard on soil humus composition, microflora and soil enzyme activities. The results showed that after covering wheat straw, the contents of soil humus, humic acid(HA) and the rate of HA to fulvic acid(FA) were increased effectively; Contents of heavy fraction, loosely combined, tightly combined humus were also increased, and especially, the relative rate of loosely combined humus compared with heavy fraction humus and tightly combined humus was also increased obviously. The amounts of bacterium, antinomyces, ammonifying bacteria and cellulose-utilizing bacteria were increased, the nitrobacteria amount was decreased; the activities of polyhenol oxidase, sucrase, alkaline phosphatase, urease and cellulose were increased, but it didnt take much effect on the activity of catalase.

Abstract:On the basis of 25-year study on long-term located experiments of fertilizer,analysis is made on he change tendency of heavy-metal content in soil of 0~20 cm which are treatd with six different fertilization trails detailed as fertilizing by N,NP,NPK,N organic fertilizer,N straw and no fertilizer. The result states that: All 6 elements present trend of increasing. The Zn content of the soil with N organic fertilizer processed, which exceeds the limit of the Soil Environmental Quality Standard II, Hg content increased massively, 114% increased than the testing foundational value. No weighty effect to the soil only N fertilizer (urea) used, use P fertilizer shall increase the heavy-metal content of the soil. The organic fertilizer, which takes rejected materials of livestock and poultry as raw materials, shall increase the heavy-metal content of the soil, Cu, Zn and Hg increased especially. The organic fertilizer, which takes rejected materials of livestock and poultry as raw materials, should be used reasonably, fertilization is an important reason to effect the change of heavy-metal in soil.

Abstract:Using 10 types of natural minerals as amendment agents of soil, we experiment of improving soil by irrigating mineralize degrees 4.05.0 g/L brackish water to farmland . The results show that the first amendment agent can reducesoil unit weight 12.23%, increase soil porosity 12.28%. Amendment agents take part in a experiment can reduce soil salt content at most to 72.5% in soil depth of 05 cm and reduce soil anion CO_3~(2-) and HCO_3~- at most to 100%. The fourth amendment agent has affects of increasing Ca~(2 ),Mg~(2 ) and reducing K~ Na~ in soil depth of 040cm. Natura minerals amendment agents of soil have taken a turn for better physical and chemistry environment of soil.

Abstract:硒肥对提高茶叶品质和增加茶树体内硒含量具有明显的促进作用。为了探讨硒对茶叶品质的影响机制,本研究进行了土施和喷施硒肥的盆栽试验。结果表明:叶面喷施和土施Na2SeO3两种施用方式对茶叶硒含量的提高及品质的改善都非常有利。叶面喷施浓度为120μgSe/ml时,喷施后第12天,春茶的硒含量最高为0.374μg/g;叶面喷施浓度为180μgSe/ml时,喷施后第18天,夏茶和秋茶的硒含量最高,分别为0.380μg/g和0.368μg/g。采用土施硒肥的方法制富硒茶时,土壤施硒量应不少于8mgSe/盆。叶面喷施浓度为180μgSe/ml时,夏茶化学品质提高最为明显,其中酚氨比下降为对照的65.73%,可溶性糖含量增加到对照的116.30%。与叶面喷施有降低儿茶素含量的作用相比,土施硒肥对整个采摘期内茶叶儿茶素的含量无明显影响,因此对改善茶叶品质特别是春茶品质的作用后者优于前者。

Abstract:Determined the soil moisture dynamic and evapotranspiriation of Caragana microphylla plantations with different ages during growth period in field condition. Result showed: there are distinctly differences on soil moisture and evapotranspiriation between plantations with different ages. Moisture of soil under artificial plantations is continual decreasing along with the increasing of ages. The moisture contents of 16 and 19 years old shrubs decreased along with the depths of soil. There is a low moisture contents lay in 70cm depths of soil. The soil under these plantations gradually translated from leached soil to anti-leached soil. Precipitation and vegetations effected soil moisture contents during growth period, and soil moisture contents appeared lowest point in June. Evapotranspiriation is continual increasing along with the plantations ages increasing and the 19 years old shrubs had the maximal evapotranspiriation. During growth phases, quantities of evapotranspiriation of all plantations are low than rainfall and occupied above 95% of rainfall at the same time. The floating dunes are different from fixation dunes. Soil moisture under floating dunes are high and quantities of evapotranspiriation are low than shrubs area.

Abstract:By time series analysis, the relationships between soil water potential and precipitation dynamic change on hillslope in the typical peak-cluster depression area of Huanjiang county in Guangxi Autonomous region have been analyzedfrom May to September in 2004, and the soil water potential was collected from 10 and 20 cm depths of the six kinds of land covers. The results show as follows:(1) with the soil character of hysteresis and retentivity with precipitation, shrubbery and hay-covered chesnut were both abundant in soil moisture storage, which of the two kinds were slightly influenced by the weather fluctuation; (2) the soil moisture content kept lower on the slope land cultivated, obviously changing with the precipitation fluctuation, yet has been adjusted to detain for long period with the help of cushaw of creeping vegetation;(3) grassland and cajanus both had great difference in depths with soil moisture content which instantaneously responded to precipitation, but the 20cm depth of the first land cover had a better moisture retention, so as to be good for the moisture compensation for the 10 cm; (4) at the age of sapling, chesnut field was nearly bare ground, its soil moisture dynamic change had little connection with vegetation, but mostly with meteorological factors, which induced the change between that of the kinds of shrubbery, hay-covered chesnut and that of the kinds of grassland, cajanus.

Abstract:Numerous studies have shown that soil particle size and weight distribution are fractals, which are generally described with fractal geometry in this paper, analysis of nine sampling soils from sandy soil blown by wind plots in Kurbantunggut desert. A fractal model for sandy soil water retention curve is derived with Van Genuchten model. The fractal dimensions of sandy soil water retention curve are calculated with experimental data for sandy soil water retention curve of nine different kinds of soils in Kurbantunggut desert. And the fractal dimensions of sandy soil water retention curve are compared to the fractal dimensions of particle size distribution which are calculated on the basis of accumulative mass distribution of soil particles. The results show that the fractal dimensions of sandy soil water retention curve and particle size distribution increase with soil texture that ranges from floating sandy soil to semi-immobile soil,and to immobile soil. The fractal dimensions of sandy soil water retention curve show slightly different form and are linear related to the fractal dimensions of particle size distribution respectively. The soil water retention curve has been predicted by fractal model, which showed that simulation values of soil water retention curve significantly close to observation values of that. This indicates that the sandy soil water retention curve can be predicted by the fractal model for sandy soil water retention curve.

Abstract:There was a large of low-quality and benefit forest which had low ecological functions in western Sichuan. The hydrological process of litter was investigated through 1 year improvement on low-quality and benefit shrub forest in middle-mountain of the upper reaches of Minjiang river. The results showed: (1) the thickness and storage of litter were significantly improved and its storage increased 32.68%. Decomposition rate of litter was accelerated in improved shrubland. (2) the maximum water-holding of litter increased 39.60% than that before shrubland improved. The maximum water-holding of litter was mainly affected by the storage and the decomposition degree of litter. (3) The retaining capacity of litter on rainfall interception also increased after low-quality and benefit shrub forest were improved. (4) the relationship of the water-holding capacity and dipping water time showed logarithmic curve((S=klnt p), and therelationship of the water absorption rate and time showed inverse curve (V=p kt~(-1)). We should study the decomposition rate of litter and soil ecological function after low-quality and benefit shrub forest improved for synthetical evaluating ecological effect.

Abstract:The Three Gorges and upstream areas is the most severe soil erosion areas in China. The concentration of NH_3-N,NO_2-N,NO_3-N,TN and TP were determined every month during June to December in 2003.Six horizontal monitoring sites and two vertical sites were set in Three Gorges reservoir. The results showed that the six surface layer water mean concentration of NH_3-N,NO_2-N,NO_3-N,TN,TP were 0.11 mg/L,0.019 mg/L,1.28 mg/L,1.62 mg/L,0.13 mg/L respectively. Along the flow direction, the concentration of TP were depressed distinctly and TN were increased. There were not the trend on NO_2-N,NO_3-N and NH_3-N.According to different depth (surface,0.6depth and 0.8depth),three monitoring sites were set in the direction of vertical. Through successive seven months monitoring, it indicated concentration of nutrient were not variety distinctly. Changing of phosphorus concentration was related to flow of the river. The maximum of total phosphorus was appeared in high flow season ,and the minimum was appeared in low flow season.

Abstract:Analyzing 183 soil samples of 16 counties in Chongqing Three Gorges reservoir area,it showed content of soil heavy metal of water-level-fluctuating zone in Three Gorge reservoir area was better than soil environmental standard grade 3.The mean Cu content was 37.0 mg/kg,ranging from 10.7 to 80.2 mg/kg.The mean Pb content was 29.3 mg/kg,ranging from 14.6 to 51.8 mg/kg.The mean Zn was 72.7 mg/kg,ranging from 47.5 to 93.3 mg/kg.The mean Cd content was 0.321 mg/kg,ranging from 0.081 to 0.864 mg/kg.The mean Hg content was 0.059 mg/kg,ranging from 0.032 to 0.204 mg/kg.The mean As was 8.65 mg/kg,ranging from 4.63 to 12.7 mg/kg.There is a remarkable positive relation between Cu and Cd. The relativities among other heavy metals are not obvious. The effect of pH to heavy metals is small. The pollution type is Cu-Cd. By the method of system cluster,the distribution of soil heavy metal are regularity. It can be disparted three parts(upper,middle and down reaches).

Abstract:The 36 reservoirs were investigated in Chongqing, concentration of chlorophyll a is 1.5952.3 mg/m~3;TP is 0.0020.598 mg/L;TN is 0.525.94 mg/L;SD is 0.483.2 m; COD_(Mn) is 0.759.3 mg/L. There are significant positive correlation between COD_(Mn),TN and chlorophyll-a, SD was significantly negative with chlorophyll-a, correlation between TP and chlorophyll-a was weak, the relation of chlorophyll-a, total phosphorus and transparency are showed by using regression method, corrected Carlson Trofic State Index are used to evaluate the eutrophication degree of 35 reservoirs, 27 reservoir were eutropher and 8 reservoir were mesotropher. Eutrophication condition of the reservoir in main city and west of Chongqing were more serious than which in Three gorges reservoir area. Nutrient output of 3 huge reservoirs were calculated and were contrasted with 67 sewage limbers, the amount of total nitrogen output only the 3 reservoirs were exceeded to 67 sewage and output of total phosphorus were about 16 percent occupied sewage.

Abstract:Through experiments of static degradation and dynamic soil column, both purification efficiency of phenol and influences of reed wetland soil were studied. The results indicate that: Purification efficiency of phenol was better of wetland soil in which was not reed-planted; Both the residence time of phenol in soil and the range of particle size affected the adsorption ability of wetland soil; Through changing soil infiltration and physicochemical properties of rhizosphere, reed can affect adsorption ability of wetland soil on phenol.

Abstract:Reported here are the results with respect to some key problems in stabilizing the shifting dunes by vegetation in the central Taklimakan: plant selection,combination,density planting season and rational irrigation. Salt accumulation and it effects on plant growth in response to different irrigation management are also compared.It is revealed that salt water with degree of mineralization over 7.416 g/L limits the growth of some less salt-resistant plants. Ditch irrigation using salt water with degree of mineralization less than 4.13 g/L has no negative effects on shrub growth in short period. While under drip irrigtion, the salt accumulation limits shrub growth to some extent. Bleaching can reduce salt accumulation.

Abstract:Through 5 years observation and investigation, the suitable range, plant recovery, sand dune moving distance, investment and production value of ten moving sand plant block models were studied. It is show that precipitation can sustain plant suvival, and plant sand block can be used for harness moving sand. All the ten models are suitable models except squared spread straw-planting Caragana microphylla model and squared sowing straw-sowing Hedysarum mongolicum and Caragana microphylla model are not suitable to upper sand. Different model has different plant recovery speed, sand float distance , investment and production value. From the point of harness effectiveness, Hedysarum mongolicum plant sand block model and Hedysarum mongolicum-Salix flavida plant sand block model arethe best, Salix flavida plant sand block model and Hedysarum-packing model are the second, Salix flavida-packing model, squared straw-planting Hedysarum mongolicum model and squared straw-planting Hedysarum mongolicum and Caragana microphylla model are the third, squared spread straw-planting Caragana microphylla model, squared sowing straw-sowing Hedysarum mongolicum and Caragana microphylla model and squared straw-planting Salix flavida model are the worst. Study results provide a scientific way for harness floating sand.

Abstract:The economic and ecological effects of the pear-upland rice system in sloping land in Three Georges reservoir area were analyzed in this paper. Comparing with the pear mono-cropping orchard, the new pear-upland rice system indicated that:(1)It improved the microclimate environment and soil fertility, reducing soil and water losses and decreased the soil erosion;(2)It increased the content of chlorophyll of pear leaves and the photosynthetic rate, and also improved the intrinsic quality of pear;(3) Weed and pest can be significantly controlled in the system so that it could reduce or limit the application of herbicide and pesticide which resulted in 60.19 kg N/hm~2 and 8.0 kg P/hm~2 of non-point source pollution load.(4)It could notably increase the economic benefits, and the land utilization efficiency increased by 44%.

Abstract:The cross region of agriculture husbandry of northwest Loess Plateau was acted as emphases study region. On the basis of many years experimental research, the regulation, layout and implementation of industry structure were carried out by the unit of county and the main body of village in the cross region of agriculture and husbandry of northwest loess plateau in the period of the tenth five-year plan, which prompted the change of tradition agriculture and the development of agriculture and husbandry combination pattern. The income of husbandry and facility agriculture occupied 43% of total income. All these provided strong technological support for local economic development and eco-environment construction.

Abstract:Chinese cropping system not only provides people grains, vegetables, etc., but also takes an important role in soil conservation. First, crops reduce soil erosion through increasing soil penetrability and reducing runoff. Second, Chinese farmers invented many of measures for soil conservation in the long term of farming practice, such as terrace, check-dam, contour farming, straw mulch, etc., all of these are proved effective in soil conservation and crops yield improvement. According to the calculated results in the paper, the weight of soil conserved by Chinese cropping system is 101.910~8 t per year, and cropping systems in Southwestern China, Loess Plateau and Northeastern China are outstanding in soil conservation. Monetary value of soil held by Chinese cropping system is also calculated by methods of market price, opportunity cost and shadow cost. The results show that the total monetary value is 4 626.6610~8 yuan per year, which accounts for 32.08% of the mean output value of Chinese cropping production during 20002002. The values of keeping soil nutrients, reducing soil abandon and alleviating sedimentation are 4 408.5010~8 yuan/a, 164.0910~8 yuan/a and 53.7410~8 yuan/a, respectively. The monetary value in Northeastern China, Loess Plateau and Southwestern China are greater, and sum of them is 2 851.810~8 yuan/a and accounts for 61.6% of total monetary value of soil conservation service provided by Chinese cropping system.

Abstract:The Yellow River basin is located in arid and semi-arid region of the northern of our country. In here the water resource is poor. The per capita water resource is only 1/3 of the average national level. The forest coverage rate is only 6%. It is 50% of the average national level. Water and soil erosion are serious. On the Middle and Upper of the Yellow Rive, the soil erosion modulus is generally above 5 000 t/(km~2a). The sand content of the Yellow River occupies the first in the world. Average sand content of many years have reached 33 kg/m~3. The reduction of water resource quantity and Increase of demand year by year have caused a series of environmental questions, such as the land desertification, the sandstorm and the Yellow River waters deterioration, etc. Project of Water Diversion from the South to the North Via the Western Course is transforms some water from Changjiang River, Lancangjiang River, Nujiang River basin of water yield plentiful to the Yellow River. The amount of water yield 17 billion m~3.The water amount of irrigation among them is used in agriculture, forest, animal husbandry occupies 55% of water quantity. It can increase vegetation, controlling water and soil erosion and contain the soil desertification. It can alleviate the imbalance between supply and demand of the water resource of the Yellow River, and improve the water quality of the Yellow River. At the same time, they can increase the length of eroding of the downstream river of the Yellow River and reduce the silt to deposit. It is favorable to the stability of the downstream river of the Yellow River.

Abstract:The regional pattern for ecological security (RPES) is a new concept, and its theory is under development. To solve the problem of pipeline safety and the ecological destroy, the paper put the theory into use in the Shannxi Section along the West-East Gas Pipeline Project, and put forward the design framework for the RPES along the pipeline. The mapping analyze shows that there are mainly 7 ecosystems including rolling hill/loessial soil/farmland ecosystem, rollinghill/loessial soil/hassock grass steppe ecosystem, plain/loessial soil/farmland ecosystem, sandy land ecosystem etc. Sensitivity analyze of soil and water loss shows that over 80% of the region is the sensitive region, which is the character of the severe loss of water and soil. 6 key ecological units are given in the long loess ridge and round hill, the area of terrene bridge between two hills (Yaoxian), the area crossing the middle and small gully,open-riverbed-ditching, around the area of concave bank of River by WEPP in loess hilly area along WEPP.At last the security pattern designs are focused on the ecosystems and key ecological units.

Abstract:This paper calculated the ecological footprint,ecological carrying capacity,ecological surplus/loss in the Weihe basin of Guanzhong region in Shaanxi province during the period of 1986~2002, with the theory and method of the ecological footprint. In this paper, the concept of ecological pressure index was put forward, and two models were set up for calculating ecological pressure index as well as predicting ecological footprint, ecological carrying capacity, ecological surplus and ecological safety changing. At the same time it assessed the demand for ecological footprint for ten thousand yuan GDP of this area. The results of study indicated: (1)The ecological carrying capacity of this area showed a tendency of reduction.(2)The ecological footprint showed a tendency of increase. (3)The index of the ecological pressure increased from 0.75 to 1.20 from 1986 to 2001, and the increased range was 0.45 which was large comparatively.(4). Guanzhon region have already been overloaded heavily and developed in an unsafe state. (5)The ecological footprint for ten thousand yuan GDP was 3.11 hm~2, and the efficiency for utilizing resource was high relatively.

Abstract:Yield and water effect, accumulation and distribution of dry matter and grain filling of spring wheat after flowering under supplementary irrigation with catchment rainfall were studied at the trial station of Dingxi county in semiarid area of central Gansu. The results of experiment showed that there were it has improved the level of yield ,WUE and IWUE of spring wheat under supplementary irrigation(SI),and there were compensation or over-compensation effect for dry land farming crop. There were highest WUE at jointing stage, and highest IWUE at jointing booting stage. Accumulation and distribution dynamics of dry matter of leafs, stems and sheathes differed from those of spikes and all plants. Accumulation, output per day and RGR of spring wheat under SI were higher than that of CK. Moreover grain filling continuance and average grain filling of wheat were improved under SI.

Abstract:Analyzing water balance of the ecosystem (area for collecting rainwater) in geomorphic unit and the hydrologic process, taking the rainwater allocation proportion, rainfall runoff volume, losing quantity of soil and nutrients in different sloping land ecosystem as parameters, considering the requirement of water balance of geomorphic unit in the area for collecting rainwater, irrigation in the sloping land, the bearing capacity to the rainwater erosion of different sloping land ecosystem and the influence of the rainwater travel from slopping land on the environment and the water-logging-disaster area as constraint condition, construction of agro-forest multi-ecosystem in hilly sloping land of red soil is fitted out with a view to water balance and reasonable land utilization structure: artificial afforestation is 30%, 15% for sown pasture, 30% for tea garden, 20% for cultivated land, and 5% for natural protection area. It characterizes as that it offers gist for construction of agro-forest multi-ecosystem in hilly sloping land of red soil with a view to water balance and suitable land utilization structure; it embodies the thought of great agriculture, corrects the tradition utilization of one unitary ecosystem in hilly slopping land; the proportion of land utilization accords with the development of social economy, can basically achieve the requirement of foodstuff security to plough land prolongation at the peak of population. This structure meets the requirement of which not only using slopping land to collecting rainwater for keeping water balance in geomorphic unit (area for collecting rainwater) ecosystem, but also the sustainable protection of agro-forest multi-ecosystem in the slopping land.

Abstract:Based on RS and GIS technologies, the landsat TM/ETM satellite images in 1987, 1991, 1996, 2000 and 2003 were interpreted and analyzed using the overlap function, which showed the temporal and spatial rules of reed land change in Baiyang Lake in the last 16 years. The research result indicated that: the area of the whole reed land showed a trend of "down-up-down". Water area and cropland were the main land cover types that reed converted. Lower places in north and east parts of Baiyang Lake were the ones occurred the conversion between reed land and water area, and higher places in northwest and southwest occurred the conversion between reed land and cropland. The relationship between area of reed land and surface water level was also studied. The result revealed that there was a significant quadratic relationship between the average surface water level in the previous 2 years and the area of reed. The relationship equation is y=-0.1573x~2 215.90x-57989 (R~2=0.97). This relationship will be of great significance for controlling the area of reed land based on surface water level and improving the efficiency of using water resource in Baiyang Lake.

Abstract:Water quality model is a key tool of water polluter transport and transform simulation. It is widely used in the field of water environment protection and water pollution prevention and cure. According to standard J2EE, satisfying expandability, maintainability of software and high rate of code reuse, taking application frame of middleware technology style as base, zero-water quality model as represent, adopting MVC software design model, water quality forecasting middleware is realized, water quality forecasting system that about Web is built,and the WebGIS technology visualization water quality simulation result is used. This system shortens model building period and enhances the model running efficiency.

Abstract:The effects of spraying plant growth regulator under drought stress on seedling growth and physiological and biochemical indexes of soybean were studied based on pot experiment. The results indicated that the plant growth regulator could increase plant height, main root length, lateral root number, root/shoot ratio, chlorophyll content, proline content and the activity of peroxydase(POD), and improve the ability of drought-resistance of soybean seedlings. Among the 4 plant growth regulators used in this experiment, PSB was the best effective for the drought-resistance of soybean seedlings.

Abstract:Soil and water conservation in construction programs becomes more and more important in local economic development and "China western development". Soil erosion from construction in the hilly area of purple soil is very serious with erosion modulus from 13 895 to 52 400 t/(km~2a) for loose construction deposits, which is much higher than that in contrast grassland. Soil erosion of loose construction deposit has special time dependant effects. Native-born liana and herbaceousplant should be chosen for soil and water conservation in loose construction deposit land.

Abstract:The water is the important media of pollutant transferring in the environment, and the material in the water can take effect on the biologists directly. This paper has discussed the methods of tracing the characteristics of pollutants existing in the different water environment, including the method of using artificial tracer, the biomarker signal method, the microelement tracer method and the isotopes tracer method, and connect them with the environmental research. In the paragraph of the method of using artificial tracer, there is the explanation about the tracer technology of neutron activation analysis and the method of Lanthanide-DTPA tracer. The biomarker signal method mainly explain the lignin, the n-alkane and the fatty acid. The microelement tracer method is mainly about Sr, Ca, Mg and REE (rare earth element) tracing. The isotope tracer method presents the advanced method of carbon isotope, nitrogen isotope, oxygen isotope and Pb tracer. The content in the end of this paper is the expectation of the application in the environment for tracer methods.