Abstract:A special soil group,characterized by a white subsurface and a chayly subsoil,is widely distributed in the east part of the Heilungkiang and Chilin provinces of Northeast China.This soil group has been described previously by some authors as podzolic and soddy-podzolic soils or solodi.A more systematic investigation of the soils by the present authors,both in field and laboratory,comes to the conclusions that the genesis of this soil group is of a hydromorphous bleached process developed periodically under the influence of temporary stagnation of soil water at the surface horizon.The Paichiang soils,according to the denomination of natives,should be regarded as a special group of hydromorphic soils and are tentatively subdevided into three subgroups-the Paichiang soil,the meadow-Paichiane soil and the glei-Paichiang soil.

Abstract:Present paper gives the content and distribution of trace elements,including Mn,Ti,Cu,B,Cr,Zn,Mo,Co,Ni,V,Sr,Ba,Pb and Sn,in soil profiles and parent materials of north-eastern China and eastern Inner Mongolia.Geographical distribution of Cu,Mn, Mo,Zn,B and Co in this region has also been studied.111 soil profiles (360 soil samplcs) were examined for the above purposes.The average content of total trace elements in various soil types are given below:Mn 840 ppm,Ti 6,500 ppm,Cu 22 ppm,B 46 ppm,Cr 103 ppm,Zn 85 ppm,Mo 2.2 ppm,Co 23 ppm,Ni 51 ppm,V 92 ppm,Sr 270 ppm,Ba 570 ppm,Pb 26 ppm,Sn 6 ppm.

Abstract:Настояшая статъя посвяшена результатам исследования водного режима черных почв северной части Северо-Востока Китая в дериод с 1954 по 1961гг.

Abstract:For the study of the micro-regional properties of soils,microelectrodes are useful for the measurements of redox potential,pH value and electric conductance.When the buffered solutions were saturated with quinhydrone,the values of theoretical potentials can be obtained by the micro pt electrode with a diameter of 0.5 mm and length of 0.2 mm.If redox potentials of soils are ranged from 80 to 450 mv,2-5 my lower than the ordinary large electrode were found as measured by the microelectrode.For the measurement of pH value of air-dried soils,the difference between the micro quinhydrone electrode and the glass electrode was insignificant.In water-logged soils with a redox potential below 350 mv,however,the exverimental error may be 0.3-0.6 pH unit.

Abstract:Present investigation involves the rate of adsorption of ammonium by some paddy soils in solutions of 0.5,0.2,0.1,0.05,0.025 and 0.01NNH₄Cl with a soil-solution ratio at 1:5.Sample used consist of seven soils collected from Southern Kiangsu with predominant clay minurals of 2:1 types and two from Kiangsi with 1:1 types.Results obtained are according to the Langmuir's and Freundlich's adsorption equations and the correlation coefficients are given.

Abstract:Pot culture experiments were conducted on three rice soils of Southern part of Kiangsu with top-dressing of ammonium sulfate.The transformation of ammonium sulfate has been studied in tespect to the changes of hydrolysiable organic nitrogen fractions,and the relationship between mineralization and immobilization of nitrogen.

Abstract:1.Засоленные почвы Сунгари-ноннинской равнины,которые мы исследовали,можно подразделитъ на слддующие основные группы.

Abstract:Разработана методика определения микроколичества сероводорода в рисовых почвах по принципе метода изотопното разбавлдниЯ при помощи радиоактивной серыS³⁵.

Abstract:A comparative study of six methods for deteemining available phosphorus on calcareous soils in Shensi was made,results obtained from which were checked against pot cultures and azotobacter plaque technique.The correlation coefficients of the six methods in respect to biological tests are given in following order:Olsen's 0.5M NaHCO₃ method, Machigen's 1% (NH₄)₂C₂O₄ method,Radet's 3.5% sodium citrate method,Egner-Rim's lactate method,Burriel-Hernando's method and Joret-Herbert's 0.2N (NH₄)₂C₂O₄ method. Olsen's NaHCO₃ method seems to be a better one over the other methods to dcterminc available phosphorus in calcareous soils.