Abstract:The effects of some physical and chemical properties of soil on the electrode potential of steel in soils were studied. Results demonstrate that the soil moisture, soil compactness, soil salts and soil pH affect the electrode potential of steel in soils apparently. Under unsaturated condition the electrode potential of seeel in soils went down as the soil moistura increased, At tlae game level of soil moisture;negative correlation was observed between the electrode pctential and the bulk density which is an index of soil compactness. Increasing in salt concentration caused a shift of elecstrode: potential to the positive direction. Concerning the effect of soil pH three regions could be divided. In the region with a pH from 4.5 to 8.0 the influence was inappreciable. In the region with a pH from 2.0 to 4.5 and from 8.0 to 9.7 ,the electrode potential of steel was negatively correlated with soil pH, and the correlation coefficients equalled -0.953 and -0.982 respectively.

Abstract:Development of mycorrhizal infections were estimated by assesing the percentage of VAM infection in growth intervals of mungbean in pot cultures with fluvo-aquic soils of Huang-Huai-Hai plain and red soils derived from quaternary red clay, granite and basalt in Jiangxi and Guangdon provinces, most of which were deficient in available phosphorus. Results showed that infections of indigenous VAM fungi in most soils were low and lag phase usually presented. In most of the fluvo-aquic soils, VA mycorrhizal infections were around 10% on the 20 days seedlings. After inoculation, infections of both mungbean and white clover in sandy and loamy fluvo-aquic soil increased to 20-30% during the early stage of seedlings.In red soils derived from quaternary red clay in Jiangxi province, VAM infection was 13% on 40 days seedlings, it increased up to 50-60% during 25-40 days by inoculation. In red soils derived from other parent materials in Guangdon province had the same tendency with those in other districts. Lag phase of infections were all decreased or even disappeared by introducing mycorrhizal fungi into the soil, and plant growth was greatly promoted.

Abstract:Works by many persons indicated that it was extremely difficult to find the shear strength-dry density-water content relation directly, so a wise approach is to find an equivalent, for shear strength with a prerequisite that it's easier to determine the correlation among this equivalent, dry density and water content. By means of rate process theory, Mitchell etc. found that there is an unique linear relationship between shear strength and number of interparticle bonds, and this relationship doesn't change with soil type, consolidation condition, density and water content. As a result, number of interparticle bonds is an equivalent of shear strength. However, it is a pity that correlation among number of bonds, dry density and water content is still not known, so looking for another equivalent is necessary.

Abstract:The adsorption and desorption of Se by three soils (latosol, red earth and yellow brown earth), kaolin and two synthetic iron oxides (amorphous iron oxids and goethite) are discussed in the present paper. On the basis of characteristics of adsorption isotherms, Freundlich equation and Lanynuir equation(C/Y=K/M+1/M·C)fit best for experimental data of samples used. The results obtained show that clay minerals play an important role in the adsorption and desorption of selenite. The amount or Se adsorbed in the samples increased with the amount of Se added, but the amounts of Se adsorbed varied greatly with the mineral composition of samples. The amounts of Se adsorbed vuere in the order: amorphous iron oxide > goethite > latosol > red earth > yellow brovvn earth > kaolin, but the desorption power was in the order: kaolin > yellow brown earth > red earth > latosol > goethite > amorpiious iron oxide.

Abstract:The relationship between the colloidal surface properties and association of clay mineral, especially 14×10^-10m mineral and clay oxides in 26 horizons of 9 profiles of the yellow brown, soil. red earth and latosol derived from granite type parent material was studied. Results indisated that: 1) The canon exchange capacity, rotal surface area and the proportion of internal surface area decline of 2:1 type clay minerals, 14×10^-10m mineral and the increase of 1:1 type clay minerals and clay oxides. This is also in correspondence with 14×10^-10m mineral being vermiculite in yellow brown soil and 14×10^-10m mineral being 14×10^-10m intergrade mineral in red soil. 2) For two soils with a similar conent and type to other clay minerals; as the 14×10^-10m mineral is vermiculite, the ration exchange capacity, total surface area and the proportion off internal surface area off soil clay is higher, but the active acidity of soil is weaker, the content of exchangeable A1 is lower, whereas the 14×10^-10m mineral is 14×10^-10m intergrade mineral, the situation of these properties is quite oppositive.

Abstract:The surface characteristics of 8 main kinds of bentonite in China are dealt with in this paper. The samples include 5 Ca-bentonites taken from Jiutai of Jilin, Longquan of Jiangsu, Choushan of Zhejiang, Xinyang of Henan and Heishan of Liaoning respectively and 3 Na-bentonites collected from pingshan of, Zhejiang and Toksun and Xiazijie of Xinjiang. And the bentonite sample from Wyoming, USA was used as a check.

Abstract:The partitioning of N from various sources within different parts of rice plant was studied. The result indicates the different N-supply characteristics of soils and fertilizers and the redistribution of soil-and fertilizer-N, which went into the plant "pool" in different times with different speed and intensity. The evaluation of fertilizing techniques are of practical meaning when the ratio of grain N% dff (or dfs) values to straw dff}dfs values which show the magnitude of contribution from different N sources to the rice grain, and the fertilizer N balance in the agricultural ecology were concerned. Fertilization increases both soil-N up-take and crop yield by changing the soil N supply characteristics. However, the "priming effect" may augment the soil N loss through volatilization.

Abstract:The performance of self-regulation of soil refers to the ability of soil itself in controling and buffering to a certain extent in the courses of physical, chemical and biological pnocesses in vivo, enabling the storage and supply of soil moisture, nutrients, air and heat to better satisfy the needs of plant growth. The adaptability of soil to unfavorable environmental or obstacle factors, i.e，its resistance preformence, is the expression of soil self-regulation preformance under special conditions.

Abstract:A wide range of natural soils in southern China were collected to study the characteristic variation and to develop a quantitative approch of soil spectral reflectance which are related to soil classification and some soil properties. A total of 81 soil samples was collected froxtn A or B horizon in 42 soil profiles which involve five main soil great groups, i.e, latosol, red earth, yellow earth, paddy soil and purplish soil. The reflectance of air-dried soils over range of 0.36-2.5μm wavelength by using a HIACTHI 340 model spectrophotometer in the liboratory.

Abstract:Barluke Mt. is located between the Aibi Lake and the Tacheng Basin-Hebuxae Mt. valley in the western Junggar mountain ous region of Xinjiang. The forest soil distributed in the mountain region is very similar to the mountain forest soil in the north slope of the Tianshan Mountains in the soil-forming conditions, soil-forming process and main soil properties. So, both the two soils should be classified into mountain gray-cinnamon forest soil, while it is nut suitable for the predecessors to divide them into mo-untain gray-forest soil. The results of this paper were obtained by comparison and analysis of a great deal of the field investigation data and indoor analysis data in the general survey on mountain forest aoils of Xinjiang in 1984.

Abstract:Frigid desert soils belong to desert soils formed under freezing conditions which are distributed in the high and cold desert zone of the Northwest Qingzhang plateau with genetic features of coarse particles, silt enrichment, iron accumulated in surface or subsurface horizon and low O. M. content, etc. Besides, gypsum obviously avccumulated in gypsic frigid desert soils. In general, there are three basic genetic horizon: 1) vesicular crust horizon, with a thickness of 1-4 cm and many pores, and being plate or squamase-shaped; 2) ferric compact horizon under vesicular crust horizon, with a thickness of 3-5 cm, contents of free iron, active iron and clay being higher than those of its upper and lower horizons and blocky in structure; and 3) gypsic horizon, with a thickness of 10-20 cm, gypsum content of 12-25% even 40% somewhere and good crvstallizatian. Thus, gypsic frigid desert soils are classified as a subgroup of frigid desert soils vccording to the presence of typical gypsic horizon.

Abstract:Based on ¹⁴C-dating, pollen analysis and physical and chemical data, the formation environment, historic evoluation process and major physical and chemical properties of chestnut soil in the northeastern marginal area of the Qinghai-Tibat plateau were studied. The following conclusions are proved: (1) The soil had already developed during the late-leistocone, but mostly developed in the middle and late Holocene; (2) The herbaceouss pollen in the soil-forming period occupies about 90%, of which Artemisid sp. and Compositae dominate, and small amount of xylophata pollen is found in some regions; (3) The profile structure of chestnut soil is made up of recent soil and paleosol developed in different time; (4) The weak weathering of soil minerals and faint humification of the soil are because of dry and frigid climate in soil forming process.

Abstract:The Recent Yellow River Delta is rich in agricultural resources, whose rapid exploitation, together with the utilization of crude oil, natural gas and brine stored therein, are of grest significance in the economical construction of both the Dongying Municipality arnd the Shengli Oilfield. The Delta, however, is confronted with the intrinsic difficulties such as its frail ecoiogical system. distruction of which can result from only a slight imprudence. Our investigation has led to the conclusion that the Yellow River Delta needs a diversified and multilevelled strategy for development, which is to be carried out in successive stages, adjusted. in the light of local conditions and put into the coastal economical system of the whole nation as an integral part so as to be built into one of the comprehensive economical area with the characteristics and advantages of both oilfield agriculture and seashore farming.

Abstract:乙撑硫脲(ethylenethiourea)是二硫代氨基甲酸酯类杀菌剂(dithiocarbamates)的一种杂质和主要环境降解产物^[1],具强致畸、致癌性^[2],因此,它在环境中的稳定性一直受到人们重视。本文应用¹⁴C标记的乙撑硫脲和近似太阳光波长分布的氙灯光解仪,研究了乙撑硫脲在土壤中的光降解。

Abstract:国内外对土壤磷素吸附特性已有不少研究。但以往的研究中发现水稻土的吸磷特性较为复杂。因此,本文拟运用Langmuir等温吸附方程及通径分析方法,探讨福建省红壤性水稻土吸磷与磷肥效应的关系。