Abstract:The Changjiang river basin is one of the regions suffering from the most severe soil erosion in China. The properties，status，distribution and its potential risks in Changjiang river basin are expounded. Soil erosion brings about many-sided harm to environment，land resources and hinders the development of hydrological works. The relationship of soil-water conservation with the sustainable development，agriculture，forestry，animal husbandry，preventing drought-flood disasters and the Three Gorges project have been interpreted. Finally，the strategy and countermeasures against soil-water TOSS alld protecting sustainable development going beyond the centuries in the Changjiang river basin have been suggested.

Abstract:At Wangdong gully experimental area in Changwu county，through systematic field experiment for more than 10 years.and by adopting high-yield and drought proof tecitniclue} in different precipitation-type years of grain crops,in the year 1993 when the rainfall tended to nor-mal level，the wheat yield was 4 9}14kg/hm²，the corn yield was 9 478. 5 kg/hm²。the grain per unit area yield was 6 256. 5 kg/hm²·which was the highest level in the history and was also the rare record in world dry farming. In the year 1995 when the drought had been the most serious since 1928，the grain yield still reached 1 504. 5 kg/hm²which was a good harvest. It was equivalent to the normal annual yield before 1980. During eighth five-year plan，in the critical condition of successively arid with two especially serious arid years in addition .the average grain yield was 3724. 5 kg/hm²，it belongs to the first-class level at the similar type regions in loess plateau. Thereby fully demostrates that the integrated abilities of getting bumper crops and disas-ter-resistance in grain production have been enhanced perimental area has gotten into a stage of sustainable development.

Abstract:Planting Asparagus on steep slope land of more than 300 with deepening level ditches in loess hilly region，the quantity of soil erosion could be decreased by 93. 5%^} 96. 2 0, o than cori-trolling field (with no plants planted in it)，and by 91. 4%-93. 1%than millet field. The aver-age net income was 4055. 7 Yuan per hmy yearly，which was much higher than that of local traditional economical plants. The experiments indecate that Uc157 is the superior cultivar of Asparagus in the region in view of its well-developed roots and growing luxuriantly. Its yield reached 7731kg/hm= the fourth year after planting.which was 1. 6 times higher than control variety of Mary Washington. Besides，the cultivar of Uc157 performed dry resistant character. The ratio of withered leaves was 38%.lower than that of the control variety. The first and second grade of Asparugjus shoots was as high as 91. 3%.

Abstract:Based on the runoff observation data and the relevant meteorological information，the relationships between charcteristics of soil and water loss·rainfall and the amount of soil and water loss in Xingjia gully watershed were made clearly by using mathematical statistic method.

Abstract:Based on the historical material and modern observed data,the dryness/wetness trendhave been forecasted by using the methods of harmonic wave analysis and class link.

Abstract:the distribution of soil ferility in Zhifang gully watershed is studied, The result shows①soil and water loss plays an important role in the impacting of land use,vegetation andartificial soil improvement on loess soil fertility;②soil and water loss also plays an important roleon the formation of main soil types;③the fertility distribution in the profile of loess soil,whichgrows on Heilu soil,is completely different from Heilu soil;④the fertility distribution in thewhole slope land of loess soil has the different propertys,namely,the fertility on upper slope ismore than that on down-slope

Abstract:Through correlation analysis to rainfall and wheat yield in Shaanxi province,an opti-mum regression model of them is established.It is indicated that in the north of Yanan,the westand east of rairifed highland in Guanzhong plain and along the north slop line of the Qinlingmountains,the yield-increasing of rainfall is not normally brought into play,but in the middlepart of Guanzhong plain and the south of Yanan,this effect brings into play to a certain extent.And the corresponding yield-increasing measures for wheat in various areas of this province areput forward.

Abstract:The water parameters and their seasonal changes of Malus micromalus,Prunusameniaca var ansu and Elacagnus angustifolia are studied by using P-V technique under field condition. The adaptive responses of the tested trees are explored under drought stress condition. The results show that the regular patterns of the seasonal change of water parameters for thesespecies are related to climate conditions,especially the water element,and the phenologilcal char-acteristics formed by adapting to the climate condition over a long period.Within growing sea-son,the weakest point of drought tolerance of these species is in spring and early summer whenyoung branches and leaves are growing,The drought tolerance becomes stronger with droughthardening and branches maturating. The idex of drought tolerance fluctuates during the growingseason. The value of and drotight tolerance index can be used as an indicator for judging thedrought tolerance of the three species.

Abstract:Based on the consecutive located fertilization of 7 years on chestnut-cinnamon soil in Zhuanyaogou vvatershed Northwestern Shanxi,the effects of increasing soil fertility and crop yieldwere studied.The results showed that the increasing yield range became higher after fertilizingthe soil consecutively,and the soil adversity resistance was improved.The effects of increasingsoil fertility and crop yield by using mixttire of organic and inorganic fertilizer;were much moresignifacant than using the organic only-or-only inorganic fertilizer,and the former’s increasingyield range on average was 1.5 times as great as the control;The application of manure mixedwith nitrogen was the best for increasing crop yield.The application of high level manure withnitrogen fertilizer had the best effect of increasing soil fertility,which was 2 times great as thecontrol.

Abstract:Six winter wheat cultivars were used to study the effects of soil moisture deficit on peroxidase(POD)isoenzyme,vegetable yield and some economic charncters.The results;howedthat the POD isoenzyme partern varied with soil water stress.t was different in winter wheat varieties and related to vegetable growth duration.POD isoenzyme bands and activity increased in the three drought resistant cultivars under soil moisture deficit condition at the shoot elongat-ing phase, but the bands did not increase in two other drought susceptible cultivars. The differ-ent performance observed under water stress conditions between drought resistant and susceptible wheat cultivars may be related to their adaptability to drought .

Abstract:Based on the data from the field fixed position tests，the effects of soil moisture and soil hardness in the semihumid and liable to drought region in eastern part of Weibei rainfed high-land are analyzed.The results indicate that subsoiling had the effect upon promoting soil water storage during summer fallow period .soil water in Zm deep was increased by 20mm more than the conventional tillage system in the sowing stage of wheat.

Abstract:Based on the test conduted in smi-arid area of loess hilly region.the southern Ningxia,the water use of crop in man-made terrace and slope land was analyzed It shows that, the change of crop production and water use efficiency is smaller in terrace,either in full rainfall year or inshort rainfall year;but for slope land,it is greater.In terrace with highest fertility,the wateruse capacity is 328.0mm,its efficiency is 0.227kg/mm;but in slope land.under the samefertility condition,its figures are 262.0mm and 0 208kg/mm separately.The way out for in-creasing production fully in terrace is to increase the amount of fertilizer applying.

Abstract:on the basis of field investigation.location observation and field artificial rainfall test,as well as using remote sensing information source in different periods, the danamic map of soil erosion in different periods are drawn up by consulting maps of land type, soil type, land use and vegetation etc.It shows dynamic change of soil erosion type by means of quantitive and locational maps .and it provides a scientific basis for evaluating soil erosion change.soil and water conserva-tion program, and comprehensive control planning.