Abstract:in the loess plateau region of China,the economic development is relatively stagnat at present.The comprehensive harness and development of soil and water conservation are the fundations for raising agricultural yield and promoting economic prosperity at rural areas.During the comprehensive harness of soil and water conservation for more than a decade of years,the broad masses,cadres,scientists and technicianes have paid close attention to raise economic benefits.They have researched in many ways and obtained some obvious results

Abstract:The loess plateau is in the western of China,it belongs to inland area.For lacking of water resources(the total water resources is 90. 6mm in depth),serious lossing of water and soil,the rainwater is becoming more and more important to resist droughts,develop industry and agriculture,and also improve economic environment.In addition,up-down topography and centralized rainfall(it counts for 65% rainfall from June to July of annual rainfall)would benefit to collect water.Therefor,many ways to gether runoff into soil have been founded and used since a long history.They are as follows:(l)Transforming topography for cutting runoff;(2)Ploughing and raking soil to keep water;(3)Increasing cover to reduce the loss of soil moisture and rise up water use efficiency;(4)Reasonable forming corp pattern and increasing input of fertilizer to improve water use efficiency;(5)Interval seeding and rotating of crops to reduce runoff;(6)Developing water harying system and establishing cellar-style agriculture with water saving use.All above methods give us a wide range for efficient use of rainfall in the area,and would accelerate economical exploitation and ecological environment establishment

Abstract:In the area of coastal sand soil,It has a obvious benefits of using forest to prevent and control the soil and water loss on embankment surface of river,gully,and irrigation canal.The average annual thickness of soil loss may be reduced by 13.5～16.6mm.In the respect of ecoenvironment,the wind velocity may be weakened by 74.2%～83.5%,the evaporation decreased by 30.3%～33.1%,the organic substance of slope soil increased by 0.4～2.8g/kg,and the salt content decreased by 30.4%～40.8%.The ratio between benefit and cost, namely,the economical benefit(E)is 5.5,that is to say that E1

Abstract:The many years experiments in slope farmland show that effects tendency of fertilizer is as follows,MNPMNNPMPNCK,the effects of applying mixed fertilizer is superion to applying single fertilizer,and the effect of applying organic matter mixed with NP is the best,the mutual effects among N,P and M are most powerful,the value of it reached 669 kg/hm2,the crop yield keeps consistent with the nutrient absorbed.Soil organic matter has no obvious change and total N content is decreased as applying single fertilizer,soil organic matter and total N content is increased as applying organic matter mixed with fertilizer.Soil valid N content is decreased as a long-term applying fertilier,but applying organic matter may alleviated this decreasing tendency.Applying P may enhance the soil valid P obviously

Abstract:Small-sized composting experiment shows that the C/N ratio and N contents of the material for composting did not influence the rate of organic nitrogen accumulation in the compost,nor the change tendency of the organic N components.After composting, the proportions of the amino acid-N and ammonia-N of the total hydrolyzable N were increased with the material rich in protein and those of the acid-insoluble N and the unidentifiable N were increased with the material rich in lignin and cellulose.The 15N added to the compost mainly constructed the amino acid-N of the organic N components.The addition of the(¹⁵NH₄)₂SO₄ during the temperaturedecreasing stage could increase the proportion of the amino acid-N.Labelling compost directly using ¹⁵N had decreased its loss and increased its transformation rate compared with labelling the material for making compost

Abstract:By using the data of field experment,climate and yield in Heyang county,the east part of rainfed highland to the north of Weihe river,the effections of drought on flue-cured tabacco growth in field was analyzed.Some drought-relief measures were prosed,through which,the tobacco was whole covered by two composed materials

Abstract:The field trials were conducted in south Ningxia province by using regression design of gerneral rotation. By means of establishing mathematical model，the relationship among N,P₂o₅，M and yield was analysised. In addition,a system of optimum model of fertilizing N,P,and M were obtained，with which the output would be above 3 OOOkg/ha in terrace and 2400kg/ha in tableland. Also，the limited line of fertilizer input were given:N 100.5kg/ha,P₂o₅105.0kg/ha,M 30 000kg/ha in terraces and N 110. 0kg/ha,P₂o₅,105. 0kg/ha，M 30 000kg/ha in tableland. Those results could be used in practice to improve yield,save fertilizer and to fore-cast yield.

Abstract:in the light of natural and economic conditions in source section of the Yangzi river,on the basis of using remote sensing technology and analysis of main factors leading to soil and water loss,the characteristics and perniciousness of different erosion typs is elaborated and the control ways is proposed

Abstract:The benefical conditions that debris flow is formed in Sanchahe valley along Du-ku highway of Tianshan mountains are frequent rainstorm,exposed rock and high and precipitous land form in alpine region of the drainage basin. Sustained high air temperature in summer can lead to ice-fall of glacier at backwall of the basin.Then,the ice-fall is melted qulkly and results in formation of glacier flood which the debris flow is simulated.Because the conditions mentioned above are still exist,debris flow at present,is in an active period

Abstract:Based on the analysis of eco-environment factors,such as landform,climate,hydrology,vegetation, etc.,the horizontal and vertical soil distribution characters in Yan'an Prefecture, Northern Shaanxi Province,were dissussed.The afforestation site type were identified and assessed.Some suggestions about the directions and measures of forestry development were put forward at last

Abstract:Based on the material of investigation and experment,according to some relevant indexs,12.43×104hm2 of transforming slope into terrace project in Qinghai province which constrcted in 1994, is quantitatively analysized about the input and output.Thereby,the benefits of socity,economy and ecology of the project is confirmed scientifically.It is fully illustrated that the project play an very important role in controlling soil and water loss,in improving the ecoevironment,it has a practical significance for promoting the crop yield of Qinghai province to reach a new step,and for promoting the economical development and taking the mountainous people from poverty to wealth

Abstract:The present condition and problems of landslide forecasting technology are discussed.It is pointed that neural network system is a new way for solving the problems of landslide forecasting.A model and general structure of network system for forecasting landslide(HPNN)are proposed,The work principle is described by means of a practical application example

Abstract:Under the prerequisite of confirming the benefits of soil and water conservation forest,some questions are discussed about the will to afforest by farmers,the cause of falling forest,the effect of the forest to prevent collapse,hydrological effect,the system and methods to evaluate the benefit,etc.Four points of suggestions were suggested