Abstract:In this paper, the authors propose that the new tectonic movement can not be considered as a factor of soil formation, but as an inner tectonic; force in relation to to-pography by which soil formation is influenced. Due to difference in the range of topographical elevation and subsidence in new tectonic movement, the types and the development orientation of topography were varied. The influence on soil formation can be summarized as follows.

Abstract:The characteristics of moisture retention of main soils in Shanghai area have been studied by tension plate method (0-1 bars) and pressure membrane method (1-15 bars). Results showed that:In general, soil water suction was conversely correlated with soil water content. Under the low water suction, the soil water-holding capacity was dependent mainly on the content of organic matter, the adsorption of organic colloids and the influence of soil structure;while under the high water suction, it was closely related to the soil texture (i.e. the content of clay) and the molecular attractive force of specific surface area as well as the adsorption of organic colloids.

Abstract:This paper deals with the effect of the concentration of sodium bicarbonate in groundwater on the alkalization of soils with different texture. According to the data from soil equilibrium experiment in laboratory, the results are summarized as follows: (1) The concentration of sodium bicarbonate in groundwater which could induce the alkalization of soils was more than 0.lg/l, and the concentration which could induce the formation of solonetz was 0.4g/l. (2) Soils with different texture adsorbed different absolute amounts of sodium from sodium bicarbonate solution of same concentration. The quantity of absorbed soodium by clay soil was more than that by silt loam, but their soil ESP were similar. (3) There was a positive correlation between the dissociated sodium and exchangeable sodium of the soils. (4) It was also found that there was a good correlation between the pIi and ESP of the soils.

Abstract:Owing to long duration of cultivation and mismanagement of black soils, the quantity and quality of organic matter and other main indices of soil fertility were decreased gradually. At the same time the properties of colloidal complex, contents of organic matter and nutrients, buffer capacity and water- and nutrient-holding capacity were decreared, and the absorbing capacity of phosphorous was increased. While with the increasing of the quantity of organic matter and regeneration and improvement in the quality of organic matter in soil by application of organic manure, some indices of soil fertility were increased correspondingly. At the same time the properties of the colloidal complex were improved, the contents of organic matter and nutrients, availability of phosphorous, buffer capacity, water and nutrient-holding capacity were increased, and combined status of humus was also improved, which brought about the promotion of the fertility of black soils.

Abstract:In this paper chemical forms and content of soil arsenic are discussed based on analytical data of thirteen soil samples collected from ten provinces of China. Part of the procedures of fractionation of phosphorus in soil proposed by Chang and Jackson (1937 ) were adopted in the experiment for the separation of arsenic in soil. Forms of arsenic separated from the soils were adsorbed-, Al-, Fe-, Ca- and oceluded-arsenates. Analytical results showed that the contents oaf the five arsenates mentioned above in the total contents of arsenic of the soils were 0-21.3%,1.1-9.0%, 1.0-16.3%, 2.5-45.8% and 32.0-86.3% respectively. It was also revealed that chemical forms of soilarsenic and its contents seemed to be closely related to the geographical distribution of soil types. With the zonal distribution of the soils in China, the occluded-arsenate was gradually decreasing, but the adsorbed and Ca-arsenates were gradually increasing from the south to the north and from the east to the west.

Abstract:The present article deals with the determination of potassium content in soil of rhizosphere in situ by the potassium selective micro-electrode. It was found that the equilibrium potential was established within 3 minutes in the soils with higher moisture content. While under lower mossture content, it was delayed up to 5 minutes. Similarly, the equilibrium in the soil with higher K⁺ concentration was established more quickly than that in soil with lower K⁺ concentration. Forty samples collected from yellow cultivated loessial soil, white bleaching paddy soil and sandy soil with different K⁺ content had been studied. The results showed that Brood correlation was found between the K⁺ concentration determined by the electrode method and the concentration of water-soluble K⁺ determined by the flame photometric method (r= 0.931).Generally speaking, the electrode method may be a useful method for estimation of K⁺ concentration in situ.

Abstract:Gonghe basin located in Gonghe and Qinghai Counties of Tibetan Autonomous Prefecture of Southern Qinghai Province is one of the main areas of food and oil crops of Qinghai Province. This paper deals tvith the basic properties of main soil types and their distribution characteristics, as well as their utilization and improvement methods based on research data obtained from soil survey during 1962-1965 and 1978-1980 in this basin.

Abstract:About 180 thin sections of various types of paddy soil were examined using a polarizing microscope, and the relationship between the micromorphological features snd the fertility characteristics of soil was studied. Based on the data obtained micro-morphological featnrea are auggeated as the diagnostic criteria for paddy soils.

Abstract:This paper deals with the forming condition, composition, structure and apparent stability constant of complex formed by calcium and CPA I ( Chlorophosphonazo I ) and its application in soil analysis. Results showed that the complex was formed at pH 9-11.5 and remained stable for 5 hr. The maximum absorption wavelength of the complex was 570-575 um, where the apparent mole absorption coefficient was 1.42×10⁴ and the apparent stability constant was 2.43×10⁶. The ratio of Ca and CPA I in the complex was estimated to be 1:1. The calibration curve was linear in the range from 0 to 40pg/25m1. A sensitive method has been developed for rapid successive determination of calcium and magnesium in the presence of iron, aluminium, zinc, cobalt, etc., using TEA and 1, 10-phenathroline as masking agents.

Abstract:Investigation has been shown that the application od air-photographs is a practicable and effective method for soil survey in desert region. mhe present paper deals mainly with the indication of image and the method of discrimination for automorphic soil and hydromorphic soil on the basis of the analysis of the interpretation features of soil air-photos in desert region.

Abstract:对重金属污染的土壤进行研究,是了解其危害性及寻求防止其影响人体健康的重要手段之一.汞、砷、镉、铬等重金属污染土壤,早已引起人们的重视,国内外都进行了不少研究,而有关铊污染土壤的研究,报道甚少.

Abstract:敌草隆为内吸传导型灭生性取代脲类除草剂,药效长,杀伤力强,通常用来防除旱地作物(如棉花)田间杂草^[1,2].然而当使用不当时,如气温、用量、施药方法、田地平整、施药时间不当等,容易对农作物造成危害,影响作物生长而且造成对土壤环境的污染¹⁾.