Abstract:In this paper,we reviewed briefly the course of research of agro-chemical compound insoil moving with surface runoff.It discussed main research achievements of experiment and mathe-matical simulation and also analized existing problems.

Abstract:The method of planning for small watershed control in china is synthesized in this paper By analysis on their theoretical method,the adaptability and limitations of varied methods of plan-ning are presented.It is also probed into that the development of comprehensive small watershed control planning in the future.

Abstract:Loess Plateau Soil and Water Conservation Project is one of agriculture development pro-jects financed by world bank.According to the world bank's suggestion,the computerized analysisand management technology have been adopted in economic analysis and feasibility study of the pro-ject.In this paper,we mainly focus on introducing some special softwares used in the preparingphase and ones will be used in management,monitor and evaluation phase. Application of this kindof software have heighten the systematicness and accuracy of project analysis and management,savea great deal of labour and materials,brought a great advance in project to pass the world bank’s ap-praisal and to be smoothly implemented.

Abstract:It is studied that,among the climatic element at Huoditang forest farm in Qinling moun-tain range,increase of direct solar radiation ,gross solar radiation,net radiation and wind speed areaccompanied by the progressive going up of elevation,and direct solar radiation and gross radiatlonincrease with elevation by the law of exponential function。 However, scattered radiation,ground ef-fective radiation,temperature,moisture pressure precipitation and evaporation capacity are goingdown with the increase of altitude。Scattered radiation and moisture Pressure decrease exponentiallywith the elevation going up,while ground effective radiation and precipilaion vary parabolically withthe elevation,which means when elevatton goes up both elements increase at the begining,but turnto decrease in a certain elevation later.The elevation is 2500 m when the maxium effective radiationappears,2 000 m when the maxium precipitation emerges.

Abstract:The results show that soil disintegration rate on the loess plateau is faster in the north-western region than in the southeastern region It takes regional change law clearly。Based on theexperiment data,we classfy the soil disintegration rate of this area as 5 regions.That is the slowestregion,very slow region,slow region,fast region and very fast region. The important factor that ef-fect the soil disintegration rate are agriculture tillage,plant or biotic growth and soil-forming pro-cess.Besides.the relationship between soil disintegration rate with soil anti-scourbility is powerfunction.

Abstract:The intercepting rainfall of grassland of Astragulus adsurgens in loess hilly region wasstudied by using weight method in this paper.The result showed that there was an equatoin as fol-lows,p_j=-0. 0186 + 0.0601CIt-0.00612C²I²t² among interecepting rainfall(P_j),grasslandcoverage(C),rain intensity(I),and rain time(t).The maximum intercepting rainfall rate was29.7%. Meanwhile,the impact of coverage,rain intensity and rain time on intercepting rainfall was discussed.

Abstract:In this paper,We mainly studied the seasonal change of NO₃-N content in soil profile ofdifferent experiment plots and the relationship between land use and crop growth in the middle partof Hessen,Germany.Moreover,the variations of NO₃-N in the soil were detected and their effectson the pollution of underground water were also discussed.Still more,Mulching effects of fallowland crops were evaluated.

Abstract:In order to study the influence of litter to surface erosion,splash amount and plot wash-ing amount were measured respectively on the surface under middle-age Mountain Poplar forest.There are two surface conditions,the first one,litter was cleared off,and another one,the initiallitter(2 cm deepth)still stayed on the ground.The results showed there are not splash erosion onthe surface on which there are initial litter and there are micro splash erosion on the surface onwhich litter had cleared off. The runoff amount were increased by 8.72%from0.257 4m³/(100m²·a)to 0.282 0m³/(100m²·a).The erosion modalus were increased by 56.08%from 1.591 5t/(km²·a)to3.623 5t/(km²·a).Because of good protection of inital litter,surface erosion hardlyoccur in the catchment area of Mountain Poplar forest.

Abstract:Based on the researchs of predecessors,as a quantitative index for the space distributionof agro-forestry structure,forest tree distribution index was introduced in this paper. By means ofsome calculating methods of the space distribution of eco-system suggested by Mr.Niu Weiyan,theforest tree distribution index was quantified.Then,the problems of quantifying space distributionof forest tree on certain area were solved perfectly.

Abstract:Optical method is a important method for soil moisture moisture measurement.Until now,theadaptability of the method to field soil is lack.In this paper,based on the variation data of field soilphysical and chemical characterstics,by analysing the variation of dielectric constant,refractive in-dex,the influnency of the soil bulk density and chemical composition,texture and temperature foroptical measurement method are struied;It was concluded that while soil bulk density and texturehave a rather effect upon optical mesaurement method,it is difficult to use the optical mesaurementmethod to determine soil moisture in the fields.

Abstract:In accordance with the characteristic of north arid and semi-arid agriculture.The effectsof agriculture technique and water conservancy on increasement yield of agricultural production wascomprehensively analyzed.Meanwhile,according to the conditons of social and economic develop-ments of the irrigation district of Baoji gorge,Shaanxi province,before and after the region beginsbeing irrigated,long series method of analysing and calculating irrigation benefit fitting for actualcondition of the region was probed into.

Abstract:Artificial aforestatin has been confined by deficit of soil water on the pleteau area.Recent studied and practice show that the three essential technical measures to survival and fastgrow up atificial aforestation in the area are to improve the quality of land preparation,to collect sur-face run off by decrease deneity of aforestation and increase row space,and to use strong nurserystock.The only way to fulfil artificeal aforestation is to carry out the three essential technical mea-sures strictly.