摘要
在控温控湿条件下 ,盆栽试验测定 1年生沙棘苗木蒸腾耗水 ,研究结果为 :不同土壤水分处理 ,生长季节沙棘苗木蒸腾速率日变化一般为单峰曲线 ,峰值多出现在 12∶0 0～ 14∶0 0时 ;含水量处理Ⅰ、Ⅱ、Ⅲ和Ⅳ苗木蒸腾速率的均值分别为 4 0 2 4 2 1± 0 4 5 2 5 7、2 92 172± 0 30 6 18、2 790 4 9± 0 346 76和 2 9333±0 384 71mmolH2 O m 2 s 1。沙棘苗木蒸腾速率季节变化出现两次高峰 ,第一次多在 7月 ,而第二次则在 9～10月。生长季节沙棘苗木单株累计蒸散耗水量随季节呈线性增加 ,土壤水分处理Ⅰ、Ⅱ、Ⅲ和Ⅳ苗木累计蒸散耗水量分别为 173 114 4、14 1 5 0 86、12 0 732 8kg和 5 7 75 10 1kg ,水分利用率分别为 0 2 810 2 8、0 198182、0 19170 9g/kg和 0 2 730 77g/kg。生长季节苗木单株蒸散耗水量呈单峰曲线 ,其耗水高峰期多出现在 7～ 8月 ;蒸发耗水量 6月最高 ,之后随着生长进程而逐渐降低 ;蒸腾耗水量的季节变化也表现为单峰曲线 ;生长季不同月份 ,蒸散耗水量、蒸发耗水量和蒸腾耗水量皆随土壤含水量的降低而逐渐降低。
The evapotranspiration of one year old Hippophae rhamnoides’ seedlings potted in greenhouse were determined under different soil moistures The results showed as following: during the growing seasons, the daily courses of the seedlings’ transpiration rates generally showed one summit curve which appeared among 12∶00 hour and 14∶00 hour The average transpiration rates of the seedlings from controlling soil moistures under 87 14%, 70 00%, 52 00% and 40 00% of the fieldmaximum moisture capacity were 4 02421±0 45257, 2 92172±0 30618, 2 79049±0 34676 and 2 9333±0 38471mmolH 2O m 2 s 1 , respectively The seasonal courses of the seedlings’ transpiration rates presented two summit curve which showed the first in July and the second between September and October The individual accumulating evapotranspiration, which were 173 1144, 141 5086, 120 7328 and 57 75101kg under 87 14%, 70 00%, 52 00% and 40 00% of the field maximum moisture capacity respectively, linearly increased with the seedling growing Water use efficiency were 0 281028, 0 198182, 0 191709 and 0 273077g kg 1 under the four soil moisture levels respectively The seasonal courses of the individual evapotranspiration rates showed one peak curve which mostly presented in July and August under the different soil moistures, so did the transpiration The water consuming from evaporation reached a peak in June and then gradually decreased with the seedling growing During the growing season, the lower the soil had moisture, the less the seedlings evapotranspired, evaporated and transpired
基金
国家"十五"科技攻关项目 (2 0 0 1BA5 1OBO10 3)
水利部"94 8"项目 (2 0 0 2 0 7)
水科院专项 (资集 0 3KY0 3)资助。
