东北大部旱情缓解 粤闽局地暴雨成灾──1997年5月

东北大部旱情缓解粤闽局地暴雨成灾—１９９７年５月—徐良炎（国家气候中心，北京１０００８１）５月份，东北大部、华北北部及黄淮等地普降喜雨，旱情缓解；西北东部、华北西部等地降水偏少，旱情持续或发展。南方大部地区雨水比较调匀，无大范围旱涝发生，但华南局地遭...

Hydraulic Ecological Characteristics of Alley Cropping Systems and Its Productivity in Low Hilly Red Soil Region.

Water loss through surface runoff and transpiration of alley cropping systems and its influence on the productivity of the components of the systems in low hilly red soil region were reported here. The results showed that compared with the original sparse grass land and conventional farming system of single peanut, alley cropping systems profoundly decreased surface runoff. However, in the dry season,the intercropped peanut was under more serious water stress, whose stomatal resistance increased and transpiration rate decreased. The diurnal variation of transpiration rate of peanut alley_cropped with Choerospondias axillaris in the system of high density of trees indicated that the peanut had been beyond its capacity of adjusting water flow under water stress, which resulted in decrease of peanut yield and its biomass. In contrast, the hedgerow trees were favored in the competition,and they grew more rapidly than their counterpart tree, which did not intercropped with peanut. The results also showed that there were less competition in the system, where Choerospondias axillaris trees were less densely planted or slow_grown trees of Eucommia ulmoides were planted.