Abstract:This paper,might provide some,perhaps fragmental,knowledge about the relation of soil (including paleosol) on the loess plateau to environmental variations.The authors are tryinh to enter into the nature and speciality of the loess deposition and loess layer and then annalyze the bidogy-climate information possibly contained in the soil characteristics.This approach might alleviate the antagonism and hence promote the cooperation between different scientific views.The authors suggests that:(1) Patieular settling modes let to particular mother material for the pedogenesis.It is just the prolonged falling accumulation and continuous alternative pedogenesis-lithificatioa of this material of "parasoil-pseudosoil" along the middle reach of the Yellow River that formed the loeaspaleosol sequence as thick as 200 meters.

Abstract:The iron oxide in soils plays a very important role in plant nutrition,soil environmental chemistry and biogeochemistry,and it is very easy to transform corresponded to the changes of environmental factors,especially the soil organic matters.The present paper deals with the iron transformation in rice rhizosphere of paddy soil derived from Quaternary red clay (QP),albic soil (AP),red soil derived from Quaternary red clay (QR) and lateritic red soil (LR) after growing rice (Oryza sativa L.cv.Yanggeng No.2)using a rhizobox.The results showed that the contents of amorphous iron oxide (Fe_o),free iron oxide (Fe_d),complexed iron oxide (Fe_a) and the activity of iron oxide in the rice rhizosphere of the paddy soils as well as the contents of Fec in rice rhizosphere of the two red soils were lower than those in the non-rhizosphere soils.The contents of Fe_o and Fe_d and the activity of iron oxide in rice rhizosphere of the two red soils,however,were higher than those in the non-rhizasphere soils,which demonstrated that iron oxide was activated in rice rhizosphere due to to the activity of rice root and the action of microorganisms on the root surface and in the rhizosphere.

Abstract:The paper deals with the inositol hexaphosphate contents and fractionation of organic P from three kinds of organic mannres and two kinds of paddy soils.The nutritional effecr of inositol hexaphosphate on the growth of rice seedlings was compared with that of inorganic phosphorus at the same P level.Inositol hexaphosphate was the main form of organic P in the organic manures and paddy soils.In pig and chicken feces,Ca-or Mg-inosirol hexaphosphate was up to 80% of the total organic phosphorus.However,in the paddy soils and cattle feces,Fe-inositol hexaphosphate was predominant in the total inositol phosphale.Fractionation of organic P indicac manures that the availability of organic P in organic manures was higher than in soils.In aseptic culture,inositol hexaphosphate had a better effect on rice seedling growth than inorganic phosphorus.

Abstract:The objective of this study was to determine the effect of zero tillage on soil microorganismas and biological activity.The field expetiment was conducted on a sandy loam soil,Which had been cultivated for many years,in Yangzhou,Jiangsu Province.After 6 years of the adoption of Zero tillage on the soil (wheat and rice rotation) 0-28 cm soils were sampled to determine microflora and biological activity so as to make a comparison between zero tillage (ZT) and conventional tillage (CT).

Abstract:The effect of additives including milk vetch,CaCO₃ and bentonite on the toxicities of copper and cadmium in soil extracts and their forms were emphatically discussed in the present paper.The ezperimental results demonstrated that of the three additives,CaCO₃ howed an extraordinary ability to lower the contents of water-soluble Cu and Cd and extractable Cu and Cd with 0.1 mol/L HCl eatractant as well as their toxicities in red soil,and it could make the 6sad Cd in red soil transform obviously from water-soluble and exchangeable forms into organit,Fe and Mn oxides occluded and sulphide forms.In other words,CaCO₃ could chapge the available forms of metals into slowly available and unavailable forms,resulting in the elimination of the toxicities of Cu and Cd in water and acid extraction solutions.

Abstract:Effects synthetic aluminum oeides (gibbsite) on positive,negative charges,and zero point of net charges (ZPNC) in five soils from southern China were studied by way of coating.After roaring with aluminum oxides,positive charges of these soils increased to varying degrees.But the increments reduced with the increase of pH value.When pH value was about 7,positive charges of four soils approched to zero,but there were still a few positive charges in the latosol.

Abstract:It is desirable to be able to estimate the fate of a pesticide applied to the agricultural fields.The widespread nature of pesticides contamination makes the problem difftcult because it is not as a ‘point source' that can be isolated and controlled.The fate is determtned by a number of environmental processes,many of which operate in the unsaturated zone of soil.A mathematical simulation technique has been developed to evaluate pesricide leaching potential.

Abstract:There are about 67000ha of acid sulfate soils in China.They art mainly distrihuted in the coastal region of the southern part of China.This study deals with the amount of some acid forms in acid sulfate soils and their interrelations.Acid sulfate soils contain a large amount of pyrite,Which is a kind of potential acid form and can produce active acidity after its oxidation.The soils contain a large amount of exchange and hydrolytic acidity,generally 0.2-10.5 cmol/kg,and have a very low pH value,generally betwrrn 3.2 and 5.5.Pyrite (FeSa) is a determinant form of acidity in the soil,but the different forms of acidity are related each other in a equilibrium system.

Abstract:According to very high correlation existing generally between erosive precipitation and ltinetic engery,a nrw algorithm of R composed of the I_30B a and the precipitation of flood xason has been initially created.Application results of new and old algorithm in different region show that the new algorithm was wider in application range,higher in the accuracy of monitoring rrosinn loss and easier to the usage in remote sensing monitoring of erosion losxs.Using the new algorithm,the R values of all rainfall erosion regions in China could be calculated and evaluted in the same accuracy,which would be beneficial to the scientific mansgement of soil and water conservation.

Abstract:The widely distributed granite weathering crust in south China is generally composed of four layers:soil organic layer (20-50 cm),red clay layer (1-10m),sandy layer (5-10 m) and fragmental layer (10-20 m),in which the red clay layer is firmly cemented Icy clay and Fe-Al oxides and thus has a higher anti-erodibility than the underlying sandy and fragmental layers.Therefores soil erosion and conservation are quite different whether ero3ed soil possesses a red clay layer or not.By comparing conservation measures,restoration of vegetation and soil fertility,and soil development of the two types of eroded soils with conservation measures taken for 22 years,the present study reveals that when eroded soil possesses a red clay layer,soil degradation and erosion are not so serious.

Abstract:This paper focuses on the genetic characteristics and vertical distribution of soils of Meihua Mountain.Situated in the southwestern part of Fujian Province,Meihua Mountain falls into mid-subtropical zone.The basic belt of soil is red earth.The soil sequence from the mountain foot upwards is in as order of red earth,yellow-red earth and yellow earth.Besides,scattered mounlain meadow soil and bog soil can be also found in the valleys over 1000 metres above sea Level.

Abstract:This paper deals with the project of ecoagriculture in the Huang-Huai-Hai Plain,which iit a comprehensive study on structures and functions of the agroecosystem as well as charaeteristics of the various subsystems,and energy conversion in the vanous subsystems,with a view to exploring interacuons among biome,soils and environment and their regulation,and to establishing various optimal artifical compound ecosystems.

Abstract:作者近年在对昆仑山-可可西里山区考察中发现在海拔5000m左右的高原面上有碱土发育,从而首次揭示了我国存在高原碱土.它主要分布在湖泊边缘、河流阶地、古湖洼地及洪积-冲积扇上,分布比较零散.高原碱土与低海拔碱土一样,具有明显的碱化层,土体紧实,棱柱状或柱状结构发育,pH>9.2,钠碱化度40%以上.

Abstract:日本黄瓜是浙江省出口蔬菜之一,由日本育种场供应黄瓜种子,于1980年开始在浙江肖山市种植,引种初期,每公顷产量可达75000公斤以上,但近年来,由于偏施化肥,黄瓜早衰严重,病虫害增多,产量和优质正品瓜的数量显著减少,据1989年的调查,在严量减产的地区,产量只有引种初期的1/3左右.为此作者于1989-1989年开展了探讨施用有机肥料对黄瓜早衰的影响的研究.

Abstract:在自然条件下,降雨淋洗是地表污染物质向下运移而污染地下水的主要途径之一,同时,也是淋洗土壤盐分、影响土壤盐分动态的重要因素之一.因此,研究降雨淋洗条件下土壤中的溶质运移,可为污染物质的处理和田间土壤水盐动态的调控提供理论基础.本文通过室内实验和理论计算对这一问题进行了初步探讨.