Abstract:Earth temperature was studied respectively, in Fb-Orthic Histosols area and Mat-Cryic Cambisols soil area at the same elevation and near in distance. The result showed that the two types of soils were under the identical climate, yet the earth temperature distribution differed significantly. According to the character of the earth temperature distribution in 40-80cm soil layer of the two soils, the soil temperature in Mat Cryic Cambisols varied dramatically averaging annually 3.4℃,with its zero temperature isoline extending fairly deep, whereas it was quite steady in Rb-0rthic Histosols, averaging annually 1.4℃ with its zero temperature isoline only reaching at 80-90cm or so. With increasing soil depth, the difference in variation of earth temperature in two types of soils became greater.

Abstract:A soil development index was developed to quantitatively measure the degree of paleosol development. This index combined paleopedogenic features with ten soil macro- and micro-morphological properties from morphological descriptions of Potou and Jiu Zhoutai loess sections in the Loess Plateau of China. Description of the micromorphological properties was based on 187 thin sections. These ten morphological properties are: rubification (color hue and chroma), total texture (texture type, stickiness and plasticity), melanization (color value), microstructure (type, grade of pedality, total porosity and void types), fine material (abundance), primary carbonate (abundance), biotite (abundance and degree of alteration), Fe(hydr) oxides (abundance), secondary carbonate (micromorphology type and abundance) and illuvial clay (interference colors, lamination features, abundance and thickness of clay film). Future study may reject some of these properties and add others. The index was preliminarily tried to the field of paleoenvironmental research. The index works well with the loess-paleosol sequences, successfully identifying paleosols and weak-paleosols from a loess-paleosol sequence.

Abstract:Rill erosion and inter-rill erosion of two soils, cultivated Acrisol and Cambisol derived from Quaternary red clay and red sandstone respectively, were studied by using simulator rainfall in subtropical China Results from experimental plots which are similar to local fields planted with peanut and Sweet potato etc., show that without outside in-flow the soil losses resulted from rill erosion are similar to that from inter-rill erosion, and that soil rill erosion rate is closely related to soil characteristic and volume of the in-flow. Effects of the same in-flow on the two types of soils are very different. Inter-rill erodibility factor K of the two soils, 0.1646 and 0.1362(10^-6gsm^-6),were also calculated respectively by using some relative equations in WEEP model.

Abstract:In this project, the soil and water loss of the sample region, the Loess Plateau of China, has been studied systematically, synthetically and macroscopically; series of quantitative indices have been set up to assess the soil and water loss of this region; GIS is used to analyze the factors of soil and water loss spatially, to aggregate the data with different origins and to extract the thematic information; the mathematical model is set up to assess the regional soil loss and finally some application results have been got.

Abstract:In view of some unresolved key methodological problems (such as defining diagnostic criteria of evaluation factors, single factor evaluation and integrated evaluation of soil quality) in soil quality evaluation at present in China and being due to fuzziness in soil quality evaluation, this paper puts forward the idea and methods for establishing single factor evaluation and integrated evaluation models by applying fuzzy mathematics. The evaluation models are applied and verified with satisfactory results.

Abstract:Mineralization of organic sulfur in four soils (Black soil, Cinnamon soil, Yellow brown earth and Red soil) was studied by means of an open-incubation system at 20℃ and 30℃ in aerobic and waterlogging conditions, separately. Results showed that the amount of S mineralized at 30℃ was significantly greater than at 20℃ (P<0.01), and also greater amounts of S were mineralized in the aerobic condition than in the waterlogging condition in black soil, cinnamon soil, yellow brown earth and red soil. Cumulative amount of S mineralized and the percentage as soil organic S of the four soils incubated in the aerobic condition at 20℃ and 30℃ was 17.53-24.35mg kg^-1 and 34.20-54.33mg kg^-1,2.5%-6.5% and 5.0%-14.5%, respectively, and in the waterlogging condition at 20℃ and 30℃ 18.14-21.15 mg kg^-1 and 26.86-30.63 mg kg^-1,2.6%-5.6% and 4.0%-7.7%, respectively. The ratio of the amount of S mineralized at 30℃ to that at 20℃ was 1.85-2.23 and from 1.28-1.71 in aerobic and waterlogging condition, respectively.

Abstract:This paper deals with the interrelations and interactions of mineral nutritive elements in the soils and flue-cured tobacco system. Samples come from five typical tobacco-growing soils-plateau red soil, red calcareous soil, alluvial red soil, yellow soil and purple soil, and three varieties of tobacco-K326, Hongda and Nc82, at six growing stages. The concentrations of K, P, S, Ca, Mg, Fe, Mn, Zn, Cu and B in the leaves and the nutrient contents extracted by AB/D multiple-elements extraction procedure, and pH content of organic matter and hydrolyzable nitrogen within the root zone soil were investigated. Principal component analysis was performed using Sinus chemometrics software. The results indicated that: i) the change in concentration of nutrients in the leaves follows a regular pattern, and the variations in chemical properties of the root zone soil are more than that between the different varieties. ii) The nutrient concentrations in the leaves are dilution effect for K, P, B, Cu, and accumulation effect for Ca iii) there is a mutual synergism among K, P, Cu and B, and an antagonism of Ca to the others in the flue-cured tobacco nutrition. iv) The key to improvement of nutrition, yield and quality of flue-cured tobacco lies in increasing organic matter content in soil and making use of the synergism of K, P, Cu and B to counteract antagonism of Ca to K, P, Cu and B.

Abstract:The adsorption of nitrate ions by three variable charge soils and four constant charge soils of China were measured under different pH, co-existing Cl^- or S0₄^2- and accompanying K⁺,Na⁺ or Ca²⁺.The results showed that the amount of NOD adsorbed by soils decreased with increasing pH. For variable charge soils, the amount of adsorbed N0₃^- in different electrolytes decreased in the order Ca(N0₃)₂>KNO₃>NaNO₃>KN0₃+KCI>KN0₃+K₂SO₄.Within the range of 0.5 to 5 mmol L^-1 of NOD added, the adsorption can be described by the Langmuir equation satisfactorily, and the adsorption energy parameter(K) as calculated from the equation was similar in magnitude when different anions and rations co-existed. This implies that the adsorption of NO₃^- is mainly determined by electric force, which can not be changed by such factors as the type and the concentration of co-existing rations and anions. These factors can only influence the adsorption of nitrate through changing the surface properties, mainly the quantity of positive charge of the soil. However, the adsorption of nitrate by constant charge soils was a little higher in Ca(NO₃)₂ Solution than that in other electrolytes. The maximum amount of adsorption by these soils was only 1.5 mmol kg^-1,corresponding to about one tenth of the adsorbed N0₃^- by variable charge soils. For these constant charge soils, a negative adsorption of NO₃^- was usually observed at low concentrations.

Abstract:Incubation and pot experiments were carried out to study the effect of organic manure on the amelioration of Cd-polluted soil. The results showed that application of organic manure could significantly reduce the content of chemically available Cd in soil. Pig manure was more effective than straw. Application of organic manure could accelerate the transformation of exchangeable Cd into WBO and OxMn. There were positive cornelations between the coutents of exchangeable Cd and WBO and those of chemically available Cd and Cd taken up by rice.

Abstract:Potexperiment, laboratory culture and the sequential extraction procedures for the speciation of Cd in soil and plant were used to study the effects of calcium carbonate (CaC03) addition on transformation of cadmium (Cd) species in a brown soil added with Cd and change of Cd forms in leaves of maize. Compared to no CaCO₃ addition, CaCO₃ addition could lower content of exchangeable Cd, but increase the specifically adsorbed Cd, Cd bound to iron and manganese oxides, and residual Cd in the soil significantly. In presence of CaCO₃, soil pH, and [Ca²⁺]and [Ca²⁺]/[Cd²⁺]in saturation extracts increased, while [Cd²⁺]decreased, significantly. It was also found that dry weight and total Ca content of roots, stems and leaves of maize significantly increased, while the contents of total Cd, extractable Cd(H₂O, 2mol L^-1NaNO₃, 10%HOAc and 2mol L^-1HCl) and residual Cd obviously decreased with adding CaC0₃. It was concluded that Cd toxicity in soil-plant system could be alleviated by CaC0₃ addition.

Abstract:The K⁺ adsorption kinetics of Fluvo-aquic soil and Cinnamon soil under different K⁺ concentration were studied. The results showed: (1) adsorption rate decreased with the increase in adsorption, and the relationship between them could be described with significant linear regressive equations, indicating the adsorption were fit for the first order equations; (2) the apparent adsorption rate constant k_a and the product of k_a multiplied by the apparent equilibrium adsorption q_∞ were significantly Sinearly correlated to K⁺ concentration C: (3) the relationship between q_∞ and C conformed to Langmuir and Freundlich isothermal adsorption equations. Based on those results the K⁺ adsorption kinetics was deduced, leading to four kinetics parameters n、k₁、k₂、q_max independent of C. With n、k₁、k₂、q_max the apparent parameters and free energy change △G of adsorption could be worked out, and under certain conditions n、k₁、k₂、q_max could also be used to judge isothermal adsorption and reckon its parameters.

Abstract:The properties of desorption dynamics of sulfate and the effects of pH and temperature in four red soils were studied. The results showed that the maximum desorption was 70%-94%. The data of desorption curves can be fitted well by the Elovich equation and two-constant kinetic equation. The amount of desorption increased and velocity of desoiption slowed down with the increase in pH The amount of desorption increased and velocity of desorption speeded up with the increase in temperature. The activation energy calculated according to Arrheius equation was 23.35 kJ mol^-1.

Abstract:K⁺ adsorption of different particle fractions of lou soil varies greatly. At certain equilibrium concentration, the sequence of the amounts of K⁺ adsorbed in different soil particle fractions is(<0.1 μm)>(<1 μm)>(1-2 gym)>(2-5 μm), the same as that of the effective cation exchange capacity of different soil particle fractions. The contribution of each particle fraction to the total amount of adsorbed K⁺ is demonstrated by adsorption contribution rate. The order of the saturated adsorption contribution rates of different particle fractions in lou soil is(<1 μm)>(1-2 μm)>(>5 μm)>(2-5 μm), and the adsorption contribution rate of clay fraction attributes to nearly 85% of the total amount. In < 1+1-2 μm,< 1+2-5 μm mixtures, the adsorption contribution rate of <1 μm increases, whereas that of 1-2 μm, 2-5 μm decreases by the power function with increasing equilibrium concentration. The adsorptive interaction of different fractions has been verified. The adsorption interaction coefficient of c, indicating that the adsorption interaction of<1 μm and 1-2 μm fractions is negative, and augments with c increment. The adsorption interaction coefficient of < 1 μm and 2-5 μm fractions is more than 1 and decreases with c increment, which indicates that the adsorption interaction of < 1 μm and 2-5 μm fractions is positive and abates with increasing c. The necessity of setting up the multi-fraction adsorption equation has been confirmed.、multi-fraction adsorption equation is q=β(c)Σr₁f₁(c).

Abstract:83 samples collected from soils of six groups derived from nine parent material types were determined for 12 trace elements along with pH, organic matter, and clay content. The distribution pattern of the soil element was investigated. The results show significant difference in element contents among samples from different parent material types while there is no distinct differences among samples from various soil groups. In addition to the level of the trace elements, the paragentic relationship of various elements demonstrates successive to their parent material as well. Because the trace elements primarily occur dispersedly in silicon minerals, the distribution patterns of the trace element correlate well with their ionic radius. In general, the distribution patterns of the elements from the fourth period of the periodical table fall into a similar pattern different from those of lead, zinc and cadmium.

Abstract:The boundary layer condition and describing equation of boundary layer for solute transport are studied in this paper. A small flux is defined as the representive value of boundary layer. Laplace transfer method is used to solve the concentration of boundary-layer problem (CSBL). The comparison of CSBL with the exact solution is conducted. Results show that the CSBL is in good agreement with the exact solution. An important application of the theory is the estimation of transport parameters of solute transporting through porous materials. This leads to a new method for the estimation of parameters by using the observation imformation of the advance of the boundary-layer with time. This new method is simple, saving time and can suffieiently utilize the observation data of boundary layer transport.

Abstract:Colonization density of Mesorhizobium huakuii JSSAI6L marked with luxAB genes on the root of Astragalus sinicus reached to the maximum (7.88 log cfu/g root) in rhizobox-soil microcosm 2 days after seed planted, then reduced and kept in a stable level for a long time. After 58 days, it rose up a little, and also the strain could dispersed to the place of 22cm from seed to root tip. The colonization dynamics in pot-soil microcosm is similar with those in rhizobox-soil microcosm. Under the field conditions, however, it reached to the maximum (7.03 log cfu/g root) 30 days after seed planted, afterward declined to the minimum (5.24 log cfu/g root) 90 days later, then began to go up to 7.89 log cfu/g root 20 days after plant harvested. Inoculation of JSSAI6L strain could increase the plant biomass of Astragalus sinicus in a large scale.

Abstract:According to measured soil salt content, groundwater table and degree of mineralization features of component of soil salt was analyzed and effect of the film laid on soil surface on salt transport from groundwater to soil surface was studied. A simple function relationship between groundwater table and soil salt content was established to provide a method of determining groundwater critical depth, considering the effect of mineralization deeree of eroundwater

Abstract:This paper is to study the law of temporal and spatial evolution of the physical properties of soils reclaimed by hydraulic dredge pump in mining area. Taking Xuzhou mining area for example, soils of various times and depths of the reclaimed land by hydraulic dredge pump were studied. Results showed that in comparison with normal farmland soil, the soil texture tended to be clayey in the topsoil and sandy in the subsoil. The soil bulk density tended to be higher in the topsoil and lower in the subsoil. Meanwhile, the content of soil water-stable granular structure tended to be lower. As time went on, the reclaimed soil showed a decreasing trend in soil bulk density in the topsoil and an increaseing one in the subsoil whereas the content of water-stable granular structure increased. In the latter the 0.5-3 mm granular structure formed quicker. After 13 years of cultivation on the reclaimed land the soil bulk density and granular structure would have reached basically that of the normal farmland soil.

Abstract:氟(Fluorine)是一种与人体健康密切相关的微量元素,人体摄入氟元素不足或过量均会对健康产生危害.从1886年H.Moissan第一次成功地利用电解法把氟元素单独分离出来至今,对自然环境中氟及其化合物的研究报道越来越多,研究的深度和广度都有很大发展.但以往的研究偏重饮水和大气中氟污染问题的探索^[1-3],对土壤中氟含量研究报道较少^[4],论述影响土壤氟含量因素的文献更为鲜见.实际上人所摄取氟的来源,除饮水之外,从各种动植物食品中摄取的氟也占有相当比例,土壤中氟的含量状况直接影响粮食蔬菜水果等作物中氟的含量,进而通过食物链传递,影响动物性食品的氟含量,最终影响人体健康.