关键词: 露水量, 露水强度, 露日数, 三江平原, 水稻, 叶面积指数

Abstract:

【Objective】 In order to discuss the dew condensation in paddy in Sanjiang Plain, the dew was monitored during the growing season from early in June to late in September. 【Method】 Dew was collected by woodstick made by poplar tree. The dew intensity was calculated and annual factual dewfall in unit area was calculated by leaf area index. 【Result】 Dew days in 2008 were more than that in 2009 and dew intensity in 2008 was higher than that in 2009. The rainfall in 2009 was much more abundant than that in 2008. Dew intensity reached the peak in August in both years. Meanwhile, dew intensity varied with the height and it found in canopy was higher than that in the height over canopy 50 cm, and the lowest was found in the ground. The conservative unit area actual dewfall estimated by LAI in paddy reached 26.2 mm and 31.4 mm in 2008 and 2009, respectively. The effect of paddy density on dew intensity could be ignored, but close planting could improve the annual dewfall.【Conclusion】Because of the promotion of LAI, dewfall increased when wetland reclaimed to paddy. Dew plays an important role in the water balance in paddy and the dewfall in 2008 and 2009 accounted for 8.68% and 6.14% of the rainfall of the same period, respectively.

Key words: dewfall, dew intensity, dew days, the Sanjiang Plain, paddy, LAI