Abstract:The great difference of wheat yield exists among different hydrological year becausethe distribution of rain is not seasonally uniform. The high yield and dry-resistant techniques aredetermined depending on the different hydrological year.Many measures,including breed,fer-tilizer and field management,should be taken to get best benefit of winter wheat production

Abstract:In the south of loess plateau,soil water properties are excellent and crops have a prop-er water environment.The field water condition and its effect on crop yield are appraised anddryland productivitv is estimated.The results show that,the rate of field water deficiency is 30%in the east and 10%in the west;in current condition of productive forces,the potential produc-tivities in dryland are 5330～6330kg/hm² and 7700～9000kg/hm² for wheat and corn respec-tively

Abstract:The current agri-ecosystem situation,existing problems on Wangdong gully water-shed,which embodies the features of loess plateau gullied region,were analyzed and the regulat-ing measures to establish an efficient agri-ecosystem were discussed

Abstract:Nutrients deficiency is the main problem restricting the development of agriculturepreduction. Increasing the amount of manure is impossible,and the area of Leguminous cropsdeclines increasingly.The key measures to solve the problem of fertilizer input are raising chemi-cal fertilizer application,applying nitrogen and phosphorous fertilizer at a proper ratio and in-creasing fertilizer use efficiency

Abstract:The experiment was arranged to apply a large scal of N-fertilizer mixed with proper P-fertilizer. The productive potentiality and effect of a small amount of N-fertilizer applied to springcorn were analysed.It was showed that the tuning point of corn yield was not clear when N-fer-tilizer applied reached to 570kg/hm². Simulating N-fertilizer effect curve with the equation Y=A+Bx+Cx²,the amount of fertilizer applied correspond ing to the biggest yield was about403kg/hm² in general years. The interrelation was more clear when simulated with equation of Y=A+Blnx or y=A·x^B,but it did not own the maximum point of production. It indicatesthat the productive potentiality of N-fertilizer to spring corn is very high.To apply very smallamount of N-fertilizer,it not only can improve yield and achieve economic benefits clearly,butalso can improve protein content in corn seed.The effect curve of N-fertilizer and yield is differ-ent with the traditional ideas at section of small amount of fertilizer applied

Abstract:Based on data of 9 years field position test,we analysed the soil nutrient's change ofthree Helu soil layer under different treatments of fertilization.The results showed that the effectof fertilization on Helu soil layer's nutrient decreases with depth increasing(generally,0～20cm20～50cm 50～80cm).The nutrient's difference of topsoil is the biggest under differenttreatments,even though the nutrient's difference of the layers below topsoil is on the decrease,but their change tendency is the same as topsoil's.Compared with rare land,available nutrient ofsoil layers under CK are decreased.To evaluate comprehensively,the effect that different treat-ments improved soil fertility is NPMMPM

Abstract:The amount,properties and dynamics of soil water resource are discussed.Three ap-proaches of management for soil water resotirce,which are increasing crop water consumptionand water use efficiency and establishing crop rotation system with proper water cycle,are pro-posed

Abstract:The rainfall(100.0 mm)at soil water storage stage in l992,which was the least val-ue during 39 years,was considered to be the main reason that the growth of wintet wheatwasstrongly stressed and yield decreased.Higher daily averaged temperature,lower air relativehumidity and less soil water application intensified the degree of drought,and the lower waterproductivity increased the degree of yield reducation.The rainfall(116.2mm)at soil water stor-age stage in 1995,which was the same level to 1992’s,caused its soil moisture before sowing tobe the lowest value during 39 years.The second lowest level rainfall at growing period during 39years had been menacing the growth of winter wheat in the whole course.The air dry for clearhigher temperature and variotis lower air relative humidity and the long-term soil dry ap-proching wither soil moisture within deep soil effected the normal physiological action of winterwheat,at last,leading to the gravest dry year during 39 years

Abstract:The predictive amounts of population and farmland in the coming 15 years in Wang-dong gully watershed were analysed.Consequential conclusions are as follows:(1)the conflict ofpopulation increasing and farmland decreasing will ease up with the social and economic develop-ment in the future.(2)the course of the easing depends on the measures adopted.(3)the scien-tific guide and requisite capital support is the key to current rural economic development

Abstract:On the basis of current situation of forest production in west weibei rainfed tableland,we put forward the tactics of sustainable development that to take fast increase as the nucleus ofeconomic benefit.For this reason,we should deal properly with following problems:(1)modifythe structure of forest species;(2)construct the artificial vegetation of diversity;(3)renew andreform of locust forest;(4 )constructing protective forest of farmland that have both protectiveand commercial benefits;(5)pay attention to economic development of courtyard forest;(6)en-couraging contract wasteland of fitting forestation to peasantry

Abstract:Based on the current situation and characteristics of forest production in the loessplateau gully area,some suggestion were made to enhance the forest eco-economic benefit:(1)keeping in mind the importance of forest;(2)increasing forest investment and feedding of woodscarefully;(3)arranging tree varieties best fitting the minim ecocondition so as to increase theplant diversity;(4)setting up rational plant pattern and building up artificial complex vegeta-tion

Abstract:Based on the building of gray system prediction model for locust current annual incre-ment of high and breast diameter,we advanced a managerial principle for the artifical locust for-est in Changwu agri-ecology experimental station,that we should use the forest as its early stageand take fostering small pole as the objective,so as to raise the economic benefit of locust forest. In the general terms,the most economic cutting age is 14～18 years

Abstract:Locust is one of the main afforestion species of soil and water conservation in the mid-dle west of China,especially in the loess plateau. As the denudation and runaway,locust forestin a large scale area still have some ecologic benefit,but the economic benefit was lower. The re-sult of experments and researchs in Changwu conuty,Shaanxi province showed that clear-cuttingand root-sprout regeneration is an efficient way of reforming lower product locust forest

Abstract:At Wangdong gully experimental areas in Changwu county,twenty-six breeds of ap-ple have been recommended in succession since 1991.The orchard of cultivars and germplasmconservation has been established.By experimenting on breed suitablity of recommended applesfor several years, we make an advance of spreading apple variety of Red Fuji,Sarkimsondelicious,Jonagold,and Wanglin etc,to improve the aunitary composition of apple breeds atpresent.Particularly,the Jonagold may be the more suitable and high-grad apple breed in re-gions of temperate zone in loess plateau

Abstract:The main eating centre pests endangering apple is Carposina niponesis Wals. at Wang-dong gully experimental area in Changwu county,the next harm is Grapholitha motesta Busck.The beginning period of ripe pest is in the ten days of last May to first June, It breed two filialsper annum. The filials were excavated 6～10 days earlier at valley slope than at Yuan surface.The factors that effect disappear and increase of ripe pests are temperature,precipitation,differ-ent breed composition and effect of prevention and cured

Abstract:The cutting down and sidewards erosion action of runoff from ground catchment of village system in small watershed，is one of the important causes which result in the extending of gully head and the breaking of topography in loess Yuan region. It is also the major factors which influence the residential safety of village people. On the basis of field investigation，location ob-servation and artifical rainfall in field，the characteristics of runoff and sediment generation on stiff and soft ground were analyzed，thus, a series of vational measures were advanced

Abstract:By the observation,analysis and appraisement to the main herbs and bushes planted inthe loess slope road of Wangdong gully,we advanced a general principle of selecting herbs andbushes to control road erosion;suggested a suitable plantting pattern of those herbs and bushes;summarized a practical skill for biological erosion control measures;and analysed the ecologicaland economic benefit of the measures

Abstract:The optimum disposition of agricultural resources and industrial development direction has its innate law. Artificial positive effect can accelerate the development of productivity. The author presented industrial development direction in hilly area of loess plateau in current even a coming duration through analysis to economic productive process，agricultural resources and pro-ductivity level in Changwu experimental area and Changwu county，including to raise grain yield，to develop gully-hilly resources, to animate a diversified economy and rural industry and sideline occupation. This direction formed a challenge to the idea of no rich without industry，and was tested and verified ire productive practical in Changwu experimental area and Changwu coun-ty in the course of seventh and eighth five year plan

Abstract:Through a synthetical analysing to the econimic status of the livestock farming,theresources of forage grass and feed,and the structure and economic effect of the livestock farmingduring 1985～1995,the author thinks that the livestock farming development has been restritedby resource of concentrate.The structure of the livestock farming tend to be rationalized throughthe structure regulated for recent 10 years.The author puts forward some proposals for the live-stock farming in future

Abstract:Based on the data of fixed monitoring to 47 peasant households at Wangdong gully ex-perimental area during 1987~1992，we analysed the major reasons for steady development of peasant household economics.As a result，we expounded that the economics of peasant house-hold would develop from the responsibility household to the concurrent household,then,to thespecialized houshold，and to the united econmics at last

Abstract:In the last 10 years，the economic income standard of peasant was increased year byyear. Through studying on the mechanism of the circulatory system of income production in Wangdong gully experimental area，the author thinks that the fruit growing will be a pillar in-dustry of forming economic income，the industry and sideline production will change from "theloosely structure" to“a very important sector" in the supporting systems of forming economic in-come，and the commodity production will be present in the process of development of agricultural production，the income standard of peasant will rise faster in future