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Spatial and Temporal Variability of N, P and K Balances for Agroecosystems in china

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Pedosphere 2005年第3期15卷 347-355页

作者： SHENRun-Ping SUNBo ZHAOQi-Guo instituteofsoilscience ChineseAcademyofSciencesNanjing210008（China）／／DepartmentofSpatialInformationScienceNanjingUniversityofInformationScienceandTechnologyNanjing210044（China） instituteofsoilscience ChineseAcademyofSciencesNanjing210008（China）

Nitrogen, phosphorus, and potassium balances for agroecosystems in china from 1993.to 2001 were calculated at national and provincial levels using statistical data and related parameters, and their spatial and temporal variabilities were analyzed with GIS to estimate the potential impacts of nutrient N, P and K surpluses or deficits to soil, water and air. At the national scale, the N and P balances from 1993.to 2001 showed a surplus, with the nitrogen surplus remaining relatively stable from 1997—2001. Although during this period the P surplus pattern was similar to N, it had smaller values and kept increasing as the use of phosphate fertilizer increased year by year. However, K was deficient from 1993.to 2001 even though from 1999 to 2001 the K deficit decreased. The spatial analysis revealed higher N surpluses in the more developed southeastern provinces and lowest in the western and northern provinces where there was less chemical fertilizer input. The serious K deficit mainly occurred in Shanghai and Beijing municipalities, Jiangsu, Zhejiang and Hubei provinces, and Xinjiang autonomous regions. For the years 1992, 1996 and 2001, N surpluses and K deficits had significant positive spatial correlations with per capita gross domestic product (GDP), per capita gross industrial output value, and per capita net income of rural households. This showed that the level of economic development played an important role on nutrient balances in the agroecosystems.

关键词： china economic factors NPK balance spatial and temporal variability

Degradation of soil Nutrients in Southeast china

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Pedosphere 2000年第2期10卷 165-170页

作者： LU RUKUN SHI ZHENGYUAN and SUN Bo(institute of soil science, the {3. academy of sciences, P.o. Box 821, Naviing 210008 china) 中科院南京土壤所江苏南京 210008

A total of 2 190 soil nutrient data in the Second National soil Survey of china were collected to assess thedegradation of soil nutrients in the hilly region of Southeast china. The definition of soil nutrient degradationis suggested firstly then the evaluation criteria are set up and the current status of degradation of red soil and latosol is assessed. The percentages of areas in four grades of soil nutrient degradation, i.e., slightlydeficient, medium deficient, severely deficient and extremely deficient, were 21.3., 43.3., 16.2% and 3.0%for soil total N; 0.7%, 6.4%, 16.7% and 76.2% for soil available P; and 25.4%, 26.3., 8.6% and 5.0% forsoil available K, respectively. The severity of soil nutrient degradation was in the order of P > N > K. Themajor factors leading to the degradation of soil nutrients in quantity include soil erosion, leaching and theconsumption by crops. And the principal faCtor affecting the degradation of soil nutrieots in availability isthe fixation of N, P and K, especially the fixation of phosphorus. The average amouat of P fixed by soils is408 mg kg-1, and upland soils can fix more P than paddy soils.

关键词： nutrient degradation red soil soil degradation

Accumulation of Organic Matter in Infertile Red soils and Its Ecological Importance

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Pedosphere 2000年第2期10卷 149-158页

作者： LI ZHONGPEI CHENG LILI and LIN XINXIONG(institute of soil science, the {3. academy of sciences, P.O. Box 821, Naroing 210008 china) 中科院南京土壤所江苏南京 210008

Field experiments on the decomposition of organic materials and the accumulation of organic carbon ininfertile red soils were conducted at the Ecological Experimental Station of Red soil, the chinese {3.of sciences, and the potential of CO2 sequestration by reclamation and improving the fertility of these soils was estimated. Results showed that in infertile red soils, the humification coefficients of organic materials were rather high, ranging from 0.28 to 0.63.with an average of 0.43. which was 41% higher than those incorresponding red soils with medium fertility. This was mainly attributed to the high clay content, highacidity and low native organic matter content of infertile red soils. Compared to those in correspondingnormal red soils, the decomposition rates of organic materials were significantly lower in infertile red soilsin the first 2 yearst thereafter no significant difference was observed between those in the two kinds of *** on the kind and amount of organic manure applied, the soil properties and the rotation systems,annual application of organic manure with a rate of 4500 to 9000 kg ha-1 increased the organic carboncontent in surface 20 cm of infertile red soils by 2.1~7.5 g kg-1 with an average of 4.7 g kg-1 within the first5 years. The organic carbon content in infertile red soils which received organic manure annually increasedlinearly in the first 10 years, thereafter it slowed down, implying that the fertility of the infertile red soilscould reach middle or high level in 1O years if the soil was managed properly It was estimated that throughexploitation of wastelands, re-establishment of fuel forests and improvement of soil fertility, soils in red soilregion of china could sequester an extra 1.50 × 1015 g of atmospheric CO2.

关键词： accumulation ecological importance infertile red soils organic carbon

Study　on　Water－Soluble　Organic　Reducing　Substances：Ⅲ．Electrochemical　Properties　of　Decomposition　Products　of　Rice　Straw　and　Their　Interactions　with　Variable　Charge　soils

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Pedosphere 1996年第2期6卷 167-173页

作者： WU YOUXIAN(institute of soil science,Acodemia Sinica,P.O.Box 821,{3. 210008 china) institute of soil science Academia Sinica P. O. Box 821 Nanjing 210008 China

Some electrochemical properties,such as PH,Eh,and voltammetric behavior,of the decomposition products of rice straw and the in eractions of these products with soils were *** PH,Eh,and amounts of organic reducing substances changed markedly during the 60-day anaerobic *** decreased sharply to pH 5 on the tenth day and then increased gradually to 7 on the 45th *** amouats of organic reducing substances increased almost synchronously with the fall of redox potential during the first 15 *** differential pulse voltammetric(dpv) behavior changed not only in the peak current but also in the peak *** fractions with apparent molecular weights lower than 200 dations appeared to be active in dpv *** electric charge of organic reducing substances was closely related to the decomposition *** 6th day of incubation was the crucial time before and after which the major part of the components was negatively charged and positively charged, *** group with a low apparent molecular weight and a negative charge was the main components responsible for the lower anodic peak *** were oxidized first during the interactions of the organic reducing substances with soils.

关键词： electrochemical properties organic reducing substances rice straw variable charge soils

Radiocarbon Dating of Vertisols in china

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Pedosphere 1996年第2期6卷 147-153页

作者： LIU LIANGWU(institute of soil science,Academia Sinica,P.O.Box 821,{3. 210008 china) institute of soil science Academia Sinica P. O. Box 821 Nanjing 210008 China

Vertisols,which are mainly developed on fiuvial and lacustrine deposits and basalt,are extensively distributed in china. 66 samples of them for radiocarbon dating were collected across 5 provinces and 1 autonomous region, ranging from warm-temperate to subtropical and tropical zones in *** soil organic matter was dated via surfaCe horizon, black soil horizon and dark-colour horizon of the vertisols,whereas carbonate through calcareous concretions and dispersed carbonate in soil profile using radiocarbon method. The present article elucidates the dates of genetic horizons,and of surfaCe and buried vertisols as well. 14C dating indicates that the surface vertisols were formed during the end of the late Pleistocene,ca.15600 years *** between depth of sampling and measured 14C age shows that age characteristics of the vertisols of china are close to those of West Germany,Italy,Turnisia,Australia and Argeentia. However, two buried vertisols developed on fluvial and lacustrine deposits were formed during different geological *** buried soils in warm-temperate zone were formed in the mid Holocene, while those in subtropics were buried at 1293. years B.P.,and formed in the end of the late Pleistocene.

关键词： buried vertisois soil￣(14)C age surface vertisols

Effect of CO_2 Enrichment on the Growth and Nutrient Uptake of Tomato Seedlings

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Pedosphere 2007年第3期17卷 343-351页

作者： LI Juan ZHOU Jian-Min DUAN Zeng-Qiang DU Chang-Wen WANG Huo-Yan State Key Laboratory of soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of SciencesNanjing 210008 （China） nanjing institute of Geography and Limnology Chinese Academy of Sciences Nanjing 210008 （China）

Exposing tomato seedlings to elevated CO2 concentrations may have potentially profound impacts on the tomato yield and quality. A growth chamber experiment was designed to estimate how different nutrient concentrations influenced the effect of elevated CO2 on the growth and nutrient uptake of tomato seedlings. Tomato (Hezuo 906) was grown in pots placed in controlled growth chambers and was subjected to ambient or elevated CO2 (3.0 or 720μL L-1) and four nutrient solutions of different strengths (1/2-, 1/4-, 1/8-, and 1/16-strength Japan Yamazaki nutrient solutions) in a completely randomized design. The results indicated that some agricultural characteristics of the tomato seedlings such as the plant height, stem thickness, total dry and fresh weights of the leaves, stems and roots, the G value (G value = total plant dry weight/seedling age), and the seedling vigor index (seedling vigor index = stem thickness/(plant height×total plant dry weight) increased with the elevated CO2, and the increases were strongly dependent on the nutrient solution concentrations, being greater with higher nutrient solution concentrations. The elevated CO2 did not alter the ratio of root to shoot. The total N, P, K, and C absorbed from all the solutions except P in the 1/8- and 1/16-strength nutrient solutions increased in the elevated CO2 treatment. These results demonstrate that the nutrient demands of the tomato seedlings increased at elevated CO2 concentrations.

关键词： CO2 enrichment nutrient strength nutrient uptake tomato seedlings

A SIMPLIFIED NUMERICAL MODEL OF 3.D GROUNDWATER AND SOLUTE TRANSPORT AT LARGE SCALE AREA

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Journal of Hydrodynamics 2010年第3期22卷 319-328页

作者： LIN Lin YANG Jin-Zhong ZHANG Bin ZHU Yan State Key Laboratory of Water Resources and Hydropower Engineering Wuhan University Wuhan 430072China institute of soil science Chinese Academy of Sciences Nanjing 210008 China

A simplified numerical model of groundwater and solute transport is developed. At large scale area there exists a big spatial scale difference between horizontal and vertical length scales. In the resultant model, the seepage region is particularly divided into several virtual layers along the z direction and vertical 1-D columns covering x-y 2-D area according to stratum properties. The numerical algorithm is replacing the full 3.D water and mass balance analysis as the 2-D Galerkin finite element method in x- and y-directions and 1-D finite differential approach in the z direction. The reasonable method of giving minimum thickness is successfully used to handle transient change of water table, drying cells and problem of rewetting. The solution of the simplified model is preconditioned conjugate gradient and ORTHOMIN method. The validity of the developed 3.D groundwater model is tested with the typical pumping and backwater scenarios. Results of water balance of the computed example reveal the model computation reliability. Based on a representative 3.D pollution case, the solute transport module is tested against computing results using the MT3.MS. The capability and high efficiency to predict non-stationary situations of free groundwater surface and solute plume in regional scale problem is quantitatively investigated. It is shown that the proposed model is computationally effective.

关键词： groundwater movement solute transport simplified model 3.D mass balance numerical simulation

Revegetation of Copper Mine Tailings with Ryegrass and Willow

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Pedosphere 2004年第3期14卷 283-288页

作者： HAOXiu-Zhen ZHOUDong-Mei SIYou-Bin StateKeyLaboratoryofsoilandSustainableAgriculture InstituteofSoilScienceChineseAcademyofSciencesNanjing210008（China）

To restore vegetation on metal mine tailings is very difficult because theyoften contain high concentrations of heavy metals, low nutrient content and low water retentioncapacity. This study involved 3.experiments that evaluated the effects of 4 treatment amendments:montmorillonite, rice straw, organic manure and chemical fertilizer on the growth of ryegrass(Lolium perenne L.) and willow (Salix viminalis L.) with Cu and Zn mine tailings from two miningareas. The results showed that ryegrass was the most tolerant of 4 crops to Cu toxicity. Also whenorganic manure, which contained high concentrations of inorganic salts, was added to the minetailings, it significantly hindered ryegrass growth (P = 0.05). Meanwhile, with ryegrass organicmanure significantly increased (P = 0.05) the extractable Cu concentration in both mine *** montmorillonite was used as a mine tailings amendment with willow, the height and tress numberat the 1st cut were significantly greater (P = 0.05) than a control without montmorillonite. Howeverthere was no significant difference for height, tress number, dry weight or root dry weight at the2nd cut. So, amendment applications to reduce metal toxicity and increase nutrients retention inmine tailings were essential during revegetation of mine tailings.

关键词： amendment copper mine tailings ryegrass (lolium perenne L.) willow (salixviminalis L.) zinc mine tailings

Paddy soil Stability and Mechanical Properties as Affected by Long-Term Application of Chemical Fertilizer and Animal Manure in Subtropical china

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Pedosphere 2007年第5期17卷 568-579页

作者： LI Jiang-Tao ZHANG Bin School of Geographic and Oceanographic sciences Nanjing University Nanjing 210093 （China） institute of soil science Chinese Academy of Sciences Nanjing 210008 （China）

Wet stability, penetration resistance （PR）, and tensile strength （TS） of paddy soils under a fertilization experiment for 22 years were determined to elucidate the function of soil organic matter in paddy soil stabilization. The treatments included no fertilization （CK）, normal chemical fertilization （NPK）, double the NPK application rates （2NPK）, and NPK mixed with organic manure （NPK＋OM）. Compared with CK, Fertilization increased soil organic carbon （SOC） and soil porosity. The results of soil aggregate fragmentation degree （SAFD） showed that fast wetting by water was the key fragmentation mechanism. Among the treatments, the NPK＋OM treatment had the largest size of water-stable aggregates and greatest normal mean weight diameter （NMWD）（P ≤ 0.05）, but the lowest PR and TS in both cultivated horizon （Ap） and plow pan. The CK and 2NPK treatments were measured with PR 〉 2.0 MPa and friability index 〈 0.20, respectively, in the Ap horizon, suggesting that the soils was mechanically unfavourable to root growth and tillage. In the plow pan, the fertilization treatments had greater TS and PR than in CK. TS and PR of the tested soil aggregates were negatively correlated to SOC content and soil porosity. This study suggested that chemical fertilization could cause deterioration of mechanical properties while application of organic manure could improve soil stability and mechanical properties.

关键词： soil aggregate stability chemical fertilization organic matter penetration resistance tensile strength