干旱地区

As far as the sustainable agriculture in arid and semiarid areas is concerned, it is an important problem to develop water-saving agriculture and increase Water Use Efficiency.

发展节水农业，提高水的有效利用率，是保证干旱半干旱地区农业可持续发展的重要问题。

The social and economic sustainable development in the arid and semiarid area in China has been restricted by sandy desertification heavily.

沙漠化是制约我国干旱、半干旱地区社会经济可持续发展的重要因素。

Of arid and semiarid open country.

产于干旱和半干旱地区的空旷乡间。

College of Resources and Environment, Beijing Forest University,The Key Laboratory for Silviculture and Conservation of Ministry of Education, Beijing Forestry University, Beijing P.

北京林业大学资源与环境学院，北京林业大学省部共建森林培育与保护教育部重点实验室，国家林业局干旱半干旱地区森林培育及生态系统研究重点开放性实验室，北京，100083

Crust or layer of hard ''.'subsoil'.

干旱或半干旱地区的''。

The phenophase, growth speed, structure of tussock, bloom habits, yield of new russian wildrye strain were studied, The results showed that the new strain has good traits of strong cold and drought-resistance, turning-green early, fast development and long vegetative growing period, more tillers, developed rootsystem, high yield and bloom trimly. It is suitable to being planted in arid and semi-arid region.

对新麦草新品系及对照山丹新麦草的物候期、生长速度、草层结构、开花习性、产量性状等生物学特性和生产性能的研究结果表明，该品系具有抗寒、耐旱性强、返青早、生长发育快、青绿持续期长、分蘖多、须根系发达、开花整齐和产量高等优良特点，适宜于干旱半干旱地区栽培，具有很好的推广种植前景。

Soil water, a sort of significant water resources, is a key in transformation among surface water, groundwater, atmospherically water and soil water.

水分是干旱、半干旱地区植被建设最重要的生态制约因子，对植被恢复具有极大的限制性。

Plastic film is a modernization planting technique in droughty and semiarid area, it is adapted to wheat, cootten, corn, peanut and so on. Plastic film can save water, protract crops vegetal time, increase production.

地膜覆膜是在干旱、半干旱地区推广使用的一种现代化种植工艺，适用于小麦、棉花、玉米和花生等农作物，能够达到节水、延长作物的生长期、增产等目的。

Plastic film is a modernization planting technique in droughty and semiarid area, it is adapted to wheat, cootten, corn, peanut and so on. Plastic film can save water, protract crop's vegetal time, increase production.

地膜覆膜是在干旱、半干旱地区推广使用的一种现代化种植工艺，适用于小麦、棉花、玉米和花生等农作物，能够达到节水、延长作物的生长期、增产等目的。

Three seriousenvironment problems of the soil erosion, desertification and salinization in the aridand semiarid area not only endanger the throughput and the stability of the dry landfarming, but also jeopard the country ecosystem security.

干旱、半干旱地区的水土流失、土地沙漠化、土壤盐碱化三大环境问题，不仅直接危害北方旱地农业系统的生产能力和稳定性，而且危及到了国家生态安全建设。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。