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Quantitative Relationship Between Land Use and Phosphorus Discharge in Subtropical Hilly Regions of china

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Pedosphere 2003年第1期13卷 67-74页

作者： YANG JINLING and ZHANG GANLINinstitute of soil science, the{3., nanjing 210008 (china) institute of soil science the Chinese Academy of Sciences Nanjing 210008 (China)

The increase of phosphorus concentration is a crucial factor causing the eutrophication of water body,while land use has an important impact on agricultural non-point sources (NPS) phosphorus discharge. Sevensites controlling the water in four sub-watersheds and the main exit of the Meicun Watershed of XuanchengCounty, Anhui Province, were investigated by dynamic monitoring of stream water and nutrient discharge,integrating interpretation of aerial image and GIS analysis to find out how the land use affects phosphorusloss with stream water in typical agriculture-forest watershed in subtropical china. These monitored sitesare different in structure of land use. Phosphorus concentration of the stream water was analyzed everyweek and at the next day of rainfall. The velocity of flow was measured by kinemometer to calculatethe runoff flux and phosphorus discharge. The results showed that the runoff flux and the discharges ofdissolved phosphorus (DP), particle-associated phosphorus (PAP) and total phosphorus (TP) had significantexponential relationships with the area percentages of forest, pond and paddy field. There existed a significantlinear relationship between the TP and PAP concentrations in stream water and the area percentages of forest,pond and paddy field, and the discharge of PAP was also significantly linearly correlated with the dischargeof suspended soil particles. There was a logarithmic linear relationship between DP and PAP discharges. Thestudy indicated that the adjustment of land use patterns and construction of ecologically sound landscapewould be an important measure to reduce the runoff discharge of phosphorus. The results would be veryuseful in building the best management practices (BMPs) of agricultural watershed in subtropics.

关键词： land use phosphorus runoff watershed

Effects of chlorothalonil and carbendazim on nitrification and denitrification in soils

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Journal of Environmental sciences 2009年第4期21卷 458-467页

作者： LANG Man, CAI Zucong State Key Laboratory of soil and Sustainable Agriculture, institute of soil {3., chinese academy of sciences,nanjing 210008, china State Key Laboratory of soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 China

The effects of chlorothalonil and carbendazim on nitrification and denitrification in six soils in upland and rice paddy environments were investigated. Laboratory aerobic （60% water holding capacity） and anaerobic （flooded） conditions were studied at 25℃ and fungicide addition rates of 5.5 mg/kg A. I. （field rate, FR）, 20 times （20FR） and 40 times （40FR） field rate, respectively. The results indicated that chlorothalonil at the field rate had a slight inhibitory effect on one soil only, and that soil did not nitrify much in the first place. But chlorothalonil at higher rates inhibited nitrification significantly in all soils. For soils JXP and JXU with a pH of less than 5.0, chlorothalonil almost completely stopped their nitrification at 20FR and 40FR during the whole 14 d incubation period. For soils HNP and HNU with a pH of greater than 8.0, chlorothalonil also significantly inhibit nitrification at 20FR and 40FR （p 〈 0.05）. However, NH4＋ that was added to the soil was also almost completely nitrified by the end of the incubation period in these two soils. The effects of chlorothalonil at 20FR and 40FR on the nitrification of JSP and JSU soils, with a pH of 5.4 and 7.2, respectively, were intermediate between the other soil types. Chlorothalonil had no effect on denitrification at the field rate and had little effect at the higher rates of application in some soils. Carbendazim had essentially no effect on nitrification and denitrification in soils assessed.

关键词： fungicide nitrification denitrification chlorothalonil carbendazim

Nutrient Discharges from a Typical Watershed in the Hilly Area of Subtropical china

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Pedosphere 2003年第1期13卷 23-30页

作者： ZHANG GANLIN, YANG JINLING and ZHAO YUGUOinstitute of soil science, the{3., nanjing 210008 (china) institute of soilscience the Chinese Academy of sciences Nanjing 210008

Agriculture is still the biggest contributor of non-point source (NPS) pollution to water bodies andrunoff discharges of nutrients and other chemicals are one of the most important pathways. This studywas conducted during 1998～1999 in a typical watershed with complex agriculture and forestry systems aswell as dotted farmer villages, in a transitional region between the mid- and northern subtropical zones ofchina. Continuous sampling of stream water was performed regularly at a weekly frequency, with additionalsampling after all major rainfall events. The discharges of N and P nutrients and suspended materials weremeasured and the total and area-averaged annual discharges of all components were calculated. The resultsshowed an uneven seasonal distribution of nutrient discharges with summer storms contributing most tothe total fluxes. This study demonstrated a high dependence of runoff volume on rainfall but the overallrunoff coefficients were dependent on land use type and watershed size. The area-averaged annual dischargesvaried greatly among the sub-watersheds with different sizes and land use structures. This is the first studyestimating the area-averaged annual discharges of N and P in the hilly areas of subtropical china, which were1.5 g m-2 a-1 and 0.1 g m-2 a-1, respectively, providing important reference values for the assessment ofregional agricultural non-point source pollution.

关键词： discharge nutrients runoff subtropical china watershed

SOTER-Based soil Water Erosion Simulation in Hainan Island

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Pedosphere 2003年第2期13卷 139-146页

作者： ZHAO YUGUO, ZHANG GANLIN and GONG ZITONGinstitute of soil science, the{3., nanjing 210008 (china) institute of soil science the Chinese Academy of Sciences Nanjing 210008 (China)

The actual and potential water erosion rates of soils with different landcovers in Hainan Island, china, were estimated based on the universal soil loss equation (USLE) anda 1:200000 soils and Terrain Digital Database (SOTER) database, from which soil water erosionfactors could be extracted. 92.8% of the whole island had a current erosion rate of lower than 500 tkm^(-2) a^(-1). soil erosion risk was considered to be high because of its abundant *** vegetation cover, the potential soil erosion rate would be extremely high and 90.8% of theisland would have a soil erosion rate higher than 2500 t km^(-2) a^(-1). Relative erosionvulnerability of different soil zones, landform types, and lithological regions of the island wascompared by introducing a relative erosion hazard parameter a. Cambosols developed from siltstoneand mudstone in low hill regions were pinpointed as soils with the highest erosion risk in theisland.

关键词： hainan island soil erosion risk assessment SOTER USLE

Cu and Zn Speciation in an Acid soil Amended withAlhalline Biosolids

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Pedosphere 2002年第2期12卷 165-170页

作者： LUO YONGMINGinstitute of soil science, the{3., nanjing 210008 (china) institute of soil science the Chinese Academy of sciences Nanjing 210008

Fractionation of metals in acid sandy loam soil amended withalkaline-stabilised sewage sludge biosolids was conducted in order toassess metal bioavailability and environmental mobility. soilsolution was extracted by a centrifugation and filtration *** speciation in the soil solution was determined by a cationexchange resin method. Acetic acid and EDTA extracting solutions wereused for extraction of metals in soil solid surfaces. Metaldistribution in different fractions of soil solid phase wasdetermined using a three-step sequential extraction scheme.

关键词： alkaline-stabilised sewage sludge chemical speciation Cu granite soil

Some Fertility Characteristics and Fertilizer Requirements of a Newly Reclaimed Upland Red soil Derived from Quaternary Red Clay

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Pedosphere 2000年第4期10卷 373-382页

作者： MA MAOTONG and XIE JIANCHANG (institute of soil science, the{3., nanjing 210008 china) 中科院南京土壤所江苏南京 210008

A series of field experiments from 1990 to 1994 in Yingtan, Jiangxi Province, were conducted on an upland red soil derived from Quaternary red clay which had been reclaimed three years before the experiments, in order to study the fertility characteristics and fertilizer requirements of the newly reclaimed soil. The field experiments included that on nutrient characteristics and fertilizer effect, that on K-supplying potential and K-Mg relationship, that on fertilization rates of K and N, etc. The newly reclaimed upland soil was low in both N and P, and its responses to nitrogen and phosphate application were very significant. The K-supplying potential was also low, so the soil was highly responsive to K fertilizer. The effect of Ca and Mg fertilizers was not so great for the reason that certain amounts of Ca and Mg were incorporated into the soil through application of calcium magnesium phosphate during land leveling before the experiments. Among the four micronutrients, B, Mo, Zn and Cu, B had the greatest effect on the soil. The fertilizer requirements of the soil were in an order of P and N > K > lime and B > Mg > Mo, Zn and Cu. Eight crops tested had different fertilizer-requiring characteristics. Rapeseed was very sensitive to P and B fertilizers. Barely was especially sensitive to P and lime and it also responded to B, Mo, Zn and Cu. And sweet potato was especially sensitive to K.

关键词： fertility characteristics fertilizer requirement newly reclaimed upland soil

An XPS Study of Nitrogen Structures in soil Humic Substances

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Pedosphere 2001年第4期11卷 321-326页

作者： WEN QIXIAO, CHENG LILI and CHEN BIYUN institute of soil science, the{3., nanjing 210008 (china) 中科院南京土壤所江苏南京 210008

X-ray photoelectron spectroscopy (XPS) was applied to examine the N structures of soil humic substances and some of their analogues. It was found that for soil humic substances XPS method gave similar results as those obtained by 15N CPMAS NMR (cross-polarization magic-angle spinning nuclear magnetic resonance) method. 70%～86% of total N in soil humic substances was in the form of amide, and 6%～13. was presented as amines, with the remaining part as heterocyclic N. There was no difference in the distribution of the forms of N between the humic substances from soils formed over hundreds or thousands of years and the newly formed ones. For fulvic acid from weathered coal and benzoqu inone- (N H-4 )-2 S O-4 polymer the XPS results deviated significantly from the 15N CPMAS NMR data.

关键词： distribution of N forms 15N CPMAS NMR soil humic substances XPS.

Applicability of Fractal Models in Estimating soil Water Retention Characteristics from Particle-Size Distribution Data

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Pedosphere 2002年第4期12卷 301-308页

作者： LIU JIANLI and XU SHAOHUIinstitute of soil science, the{3., nanjing 210008 (china) institute of soil science the Chinese Academy of Sciences Nanjing 210008

soil water retention characteristics are the key information required in hydrological modeling. Frac-tal models provide a practical alternative for indirectly estimating soil water retention characteristics fromparticle-size distribution data. Predictive capabilities of three fractal models, i.e, Tyler-Wheatcraft model,Rieu-Sposito model, and Brooks-Corey model, were fully evaluated in this work using experimental datafrom an international database and literature. Particle-size distribution data were firstly interpolated into20 classes using a van Genuchten-type equation. Fractal dimensions of the tortuous pore wall and the poresurface were then calculated from the detailed particle-size distribution and incorporated as a parameter infractal water retention models. Comparisons between measured and model-estimated water retention cha-racteristics indicated that these three models were applicable to relatively different soil textures and pressurehead ranges. Tyler-Wheatcraft and Brooks-Corey models led to reasonable agreements for both coarse- andmedium-textured soils, while the latter showed applicability to a broader texture range. In contrast, Rieu-Sposito model was more suitable for fine-textured soils. Fractal models produced a better estimation of watercontents at low pressure heads than at high pressure heads.

关键词： fractal model particle-size distribution soil water retention characteristics

Tolerance of VA Mycorrhizal Fungi to soil Acidity

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Pedosphere 2001年第2期11卷 105-113页

作者： LIN XIANGUI, WANG SHUGUANG and SHI YAQIN institute of soil science, the {3. academy of soil sciences, nanjing 210008 (china) 中科院南京土壤所江苏南京 210008

A 45-day greenhouse experiment was carried out to determine effect of vesicular-arbuscular (VA) mycorrhizal fungi on colonization rate, plant height, plant growth, hyphae length, total Al in the plants, exchangeable Al in the soil and soil pH by comparison at soil pH 3.5, 4.5 and 6.0. Plant mung bean (Phaseolus radiatus L.) and crotalaria (Crotalaria mucronata Desv.) were grown with and without VA mycorrhizal fungi in pots with red soil. Ten VA mycorrhizal fungi strains were tested, including Glomus epigaeum (No. 90001), Glomus caledonium (No. 9003.), Glomus mosseae (No. 90107), Acaulospora spp. (No. 3.), Scutellospora heterogama (No. 3.), Scutellospora calospora (No. 3.), Glomus manihotis (No. 3.), Gigaspora spp. (No. 47), Glomus manihotis (No. 49), and Acaulospora spp. (No. 53.. Being the most tolerant to acidity, strain 3. and strain 3. showed quicker and higher-rated colonization without lagging, three to four times more in number of nodules, two to four times more in plant dry weight, 3.% to 60% more in hyphae length, lower soil exchangeable Al, and higher soil pH than without VA mycorrhizal fungi (CK). Other strains also could improve plant growth and enhance plant tolerance to acidity, but their effects were not marked. This indicated that VA mycorrhizal fungi differed in the tolerance to soil acidity and so did their inoculation effects. In the experiment, acidic soil could be remedied by inoculation of promising VA mycorrhizal fungi tolerant of acidity.

关键词： acidity crotalaria mung bean mycorrhiza strain