中国生态农业学报Issue(12)：1433-1439,7.DOI:10.13930/j.cnki.cjea.141030
稻田露水对水稻生长的影响研究
Effect of paddy dew on rice growth
摘要
Abstract
Dew, a crucial element of water cycle in farmland ecosystems, plays an important role in water and nutrient balance in paddy field. As a form of wet deposition, dew is a major pathway for the flow of acidic pollutants from the atmosphere to the biosphere. Acidic dew can damage protective surfaces of leaves, interfere with guard cells and poison plant cells. With dew as a surfactant by nutrient adherence to leaves, recognition of dew as an important factor of nutrient uptake is particularly significant. Dew, as a nutrient input, has always been ignored. Identifying the nutrients in dew is necessary to determine the significance of leaf dew in agricultural practices. The goals of this study were to investigate pH and essential nutrients [ammonium nitrogen (NH4+-N), nitrate nitrogen (NO3−-N) and phosphate (PO43−-P)] in paddy dew and to explore the role of dew in nutrition availability to rice. To this end, in situ dew samples in paddy field were collected from the early July to early October of 2013 at the Sanjiang Plain Paddy Experimental Station (47°35′N, 133°31′E) of Chinese Academy of Sciences. The leaf dew samples were collected 30 min before sunrise on heavy dew days and a total of 22 dew samples were collected directly on rice leaves. A conservative unit area of actual dewfall estimated by LAI in paddy field was 28 mm in 2013. Dew was accounted for 8.3%of total rainfall during the period of study. NO3−-N concentration in dew was significantly (P<0.05) greater than NH4+-N and PO43−-P concentrations. Based on statistical analysis, pH affected PO43−-P and NH4+-N concentrations of dew in paddy field. Dew contained more NH4+-N, NO3−-N and PO43−-P than rain. pH of dew was in the range of 5.34−7.10 with a mean of 6.37, which was not strong enough to cause damage to rice leaves in paddy field. The higher concentrations of N and P in dew were attributed to dry deposition on wet surfaces and variations in composition at high-altitude (cloud level) and low-altitude (ground level) aerosols and gases, to which the dew and rain were exposed. The contribution of leaf dew to rice growth was limited because of its limited condensation time. The deposition amounts of NH4+-N, NO3−-N and PO43−-P in the 28 mm dewfall from July to October in the paddy field were respectively 0.11 kg·hm−2, 0.22 kg·hm−2 and 0.04 kg·hm−2. Although nutrients were in low concentration in the dew, dew-nutrient supply was long-term. Leaf dew was not temporal, while the foliar fertilizer was evaporative. Thus leaf dew contributed more nutrients to paddy field that subsequently enhanced significant rice growth. The deposition amount of NH4+-N, NO3−-N and PO43−-P of dew were about 100 times as much as that of foliar fertilization. In addition, dew condensation on both sides of the leaf enhanced more effective uptake of nutrients. Therefore N and P in dews in paddy fields were other significant source nutrients. Dew was an important pathway for the nutrient transfer in paddy fields.关键词
水田露水/叶面肥/输入量/营养沉降/作物营养/生长发育Key words
Dew in paddy field/Foliar fertilizer/Input/Nutrient deposition/Crop nutrient/Crop development分类
资源环境引用本文复制引用
徐莹莹,阎百兴,汤洁,祝惠..稻田露水对水稻生长的影响研究[J].中国生态农业学报,2014,(12):1433-1439,7.基金项目
国家自然科学基金项目(41401229)和国家水体污染控制与治理科技重大专项(2012ZX07201004)资助 （41401229）
