Abstract:Permanent sample plots were laid under forests in the area of 3045-3125N.lat.and 10252-10324E long.with the altitude of 1200-4300 m above sea level in the Wolong Natural Reserve.Sample plots were set up on 5 mountain forest soils,i.e mountain yellow soils under the evergreen forest,mountain brown forest soils under the deciduous and broad-leaved forest,moumain dark brown forest soils under the coniferous deciduous and broadleaved mixed forest,mountain brown dark coniferous forest soils under the pue fir forest,and alpine meadow soils under the alpine meadow.Observation began in 1981 and ended in 1984.Structural patterns,total biomass (11.24-113.94 t/ha),chemical and physical prbperties,elemental content of the forest floor were studied.Finally,the function of forest floor on wate conservation,nutrient supply,promoting biological respratory intensity and soil development are discussed.

Abstract:Numerical simulation method was used to study the transfer of soluble salts in soil.Evaporation and infiltration of water,precipitation and solution of salts in soil,and fluctuation in ground water table were considered in the computer simulation program.The simulated results of movement of salts over 9 months period showed that (1) this method can be use to simulae movement of salts in soil not only over short peiiod but also over one year;(2) more precipitation in rainy season than in other seasons is more favorable for salt leaching and desalination of soil;(3) the movement of salts in soil is affected by the changes of ground water table in combiantion evaporation and precipitation.

Abstract:The productivity and allocation of nutrient elements and the biological nutrient cycling in two typical grasslands in the Xilin River Valley,Inner Mongolia were studied.Results obtained showed that the above-ground biomass was about 210g·m^-2.in Aneurolepidium chinense steppe (A.C.S.) and around 140-170 g·m^-2 in Stipa grandis steppe(S.G.S.).The under-ground biomass was 2837g·m^-2 in A.C.S.and 1596g·m^-2 in S.G.S.(0-100cm) in 1985,and 1627 and 870g·m^-2(0-70cm) in 1986,respectively.The Root/Shoot ratio varied from one grassland type to another and from year to year being in the range of 5-12.

Abstract:Caloric value of humic acid in different soils determined through oxygen-bomb calorimeter method showed that the humic acid in different soils has different energe tic states and the total energetic state of soil humic acid was positively correlated with the soil organic matter,total nitrogen and the amount of soil humic acid.The humic acid pyrolytic properties observed by means of DTA and TG methods in different soils indicated that the humic acid from different soils showed similar heat effect peak and weight loss peak in DTA and DTG curves.Difference was found in its homologous enthalpy change (△H),the percentage of weight loss (W%),the maximum rate of weight loss (dW/dT) m,activation energy (E),and the specific rate constant(K₀).

Abstract:The present papa deals with the contribution of hydrous oxides to surface charges of soils,clays and synthetic amorphous aluminosilicates.The results of experiments showed that hydrous oxide-type surfaces could be divided into two sub-groups which had totally different surface churge characteristics.In the studied samples,iron and aluminium oxide were pH-dependent posirive charge surface,silica was pH-dependent negative charge surface.

Abstract:Field trials have been conducted on two types of soil:Semihydromorphic soil and red earth in Zhejiang province,where available K content in these soils was low.Cotton plants (Gossypium hirsutum L.) grown on the above soils showed a signficant correlation between K content in leaves and lint yield at different stages of growth.According to the degree of K-deficiency of cotton plants response to the exchangeable K in soils,four catagories may be divided:1.exchangeable K>90 ppm,no K-deficiency;2,exchangeable K=70-90 ppm,latent deficiency;3.<70 ppm,deficiency;4.<50 ppm,severe deficiency.A high significant positive correlation between K content in cotton leaves and exchangeable K in soils,r=0.928.The regression equation is:y=0.1009-1-0.00467 x where,is K content in cotton leaves at flowering-bolling stage,x is exchangeable K in soils.

Abstract:Study on soil aggregate and soil moisture-thermal regime in paddy field under no-tillage and ridge culture was carried out in east Sichuan Province in 1985-1987.The results indicared that under no-tillage condition of paddy soil the aggregates of <0.01 mm tended to be increased in the aggregates the mineral microaggregates and Fe,A1-organic microaggregates of<0.01 mm increased in varous extent while Ca,Mg-organic microaggregate of <0.01 mm signicantly decreased.Under such condition,the soil was in a new and harmonic state,which would accelerate the promotion of potential soil fertility.

Abstract:The regression analysis results of raft of ferrtilizer,amount uptaken by crops and accumulation of soil nutrients in the localized trial of fertilizers on wheatcorn on yellow fluvo-aquic soils during 1981-1986 showed that 8.76% of chemical fertilizer-N and 42.54% of organic fertilizer-N entered into soil N pool,17.61% of chemical fertilizer-P and 17.20% of organic fertilizer-P into soil available P pool,and 4.5% of chemical fertilizer-K and 2.3% of organic fertilizer-K into soil available K pool.Chemical fertilizers tended to increase in organic matter content of the soils,While significantly good effect of organic fertilizers was found on supplementing soil nutrients such as P and K and improving soil physical properties.Combined application of chemical and organic fertilizers was effective both in promoting soil fertility and raising crop yield.

Abstract:This research work began in 1977 and has been continued for ten years.Field experiments were conducted in the region of yellow fluvoaquic soil in north China.Data obtained showed that the increase in total carbon of soil through application of different organic manures appeared much more significant than that applied with chemical fertilizers.At the same time,the contents of various humus fractions and the amount of waterstable soil aggregates were also increased greatly by application of organic manures.The above mentioned phenomena could be observed by micro morphological characteristics of the soil.Correlations between soil treatmenu and crop yields were quite significant in spite of changes of weather conditions during the past nine years.By assuming,that the contents of humus,water-stable soil aggregates,etc.be reliable index of soil fertility,the effect of wheat straw and organic manures on crop yield are much greater than that of chemical fertilizers.

Abstract:This paper deels with the total amounts and cintents of different forms df Zn and Mn in eight kinds of organic manure i.e. stable manure,pig,cattle,sheep,chicken,duck,rabbit and silkworm feces.Meanwhile,the activities of different kinds of enzymes in organic manure were also studied.It was shown by experimental results that organic manure was a good fertilizer for providing plants with Zn and Mn nutrients.Organic manure could increase the availability of Zn and Mn in soil,but as to the effect of organic manure on the mobilization of soil nutrients,a difference between Zn and Mn was found.Organic manure was slow and weak in its supplying-intensity of Mn nutrient to plants,but high in residue for providing available Mn to soil.On the contrary,the effect of organic manure on Zn was just opposite to Mn.After planting two crops——barley and rice,with organic manure combined with chemical fertilizer applied to the first crop,a serious deficiency of Zn in the third crop (late rice) was found.

Abstract:Owing to difference in relief and climate between the north and south of the province,the distribution of the soils in Shannxi are different most of the soils are neutral and slightly alkaline in reaction but a part of slightly acid soils are distributed in south Shannxi.Previous experiments conducted in 1961-1980 by the authors had proved the effect of Mn fertilizezr on most of the soils in this province.The present paper deals with the gradation of available Mn in soil,reasonable application of Mn fertilizer in the soils of various districts of the province,the distribution regularity of Mn in soils and the conditions of applying Mn fertilizer.

Abstract:This paper deals with the comparative study of the genetic properties of soils in arid tropical and subtropics regions of China.The results showed that,(Ⅰ) as compared with the corresponding soils in humid regions all the soils in arid areas are the same in properties,with weeker eluviation,higher pH and base saturation,a little difference between CEC aed ECEC,a very low amount of variable negative charge,a high ferritization coefficient,low hydration coefficient,and low contents of active Fe and A1 which indicates that the soil developing intensity is low.(2) Owing to the different hydrothermal condition the soils in various arid regions are different in their developing intensity.The developing intensity of the soils in various regions studied is in a desconding sequence of the soil in west Hainan (in ferrallitic stage) >the soil in Yuanjiang Yunnan (weak ferrallitic) the soil in Tianlin,Guangxi (parafereallitic) >the soil in Yuanmou Yunnan (fersiallitio) >the soil in Dukou,Yunnan (scallitic).

Abstract:Comparison has been made among three soil classification systems,i.e.genetic system,numesical system and taxonomic system.Through classification of 71 profiles.Results obtained has shown the following points:1.Owing different bases and criteria according to which the soils are classifical,the differences among the three systems occur mainly in categories of soil order and great soil group.The diagnostic characteristics which the three systems are based on are substantially not fully agree with soil forming stages and allitization intensity.

Abstract:为了改变伐林栽参的生产方式,实行“参农轮作”,以促进山区、半山区和平原地区农村参业生产的发展,并保护林业资源和生态平衡.我们通过农田土壤与高产人参腐殖土壤理化性状对比研究,找出两者的差异,以便用人工手段,将农田调控到高产人参所需的立地条件,并进行田间试验,为农田栽参提供科学依据.