水稻冠层光合有效辐射的时空分布特征  

Spatiotemporal distribution of photosynthetically active radiation in rice canopy

作　　者：李艳大[1] 汤亮[1] 张玉屏[1,2] 刘蕾蕾[1] 曹卫星[1] 朱艳[1] 

机构地区：[1]南京农业大学江苏省信息农业高技术研究重点实验室,南京210095 [2]中国水稻研究所,杭州310006

出　　处：《应用生态学报》2010年第4期952-958,共7页Chinese Journal of Applied Ecology

基　　金：教育部新世纪优秀人才支持计划项目(NCET-08-0797);国家高技术研究发展计划项目(2006AA10Z219;2007AA10Z219;2007AA10Z225);国家重点基础研究发展计划项目(2009CB118608);江苏省自然科学基金项目(BK2009307)资助

摘　　要：以2个不同株型水稻品种为材料,设置高、中、低3个施氮水平,利用SunScan冠层分析仪于灌浆期系统测定了不同施氮水平下不同株型水稻品种植株形态和冠层内光合有效辐射(PAR)的时空分布状况.结果表明:施氮量对水稻株高、穗弯曲度和茎叶夹角有明显影响;群体叶面积的垂直分布呈中部>上部>下部的分布特征,最大分层叶面积指数(LAI)出现在0.60相对高度处.冠层内平均PAR透光率从顶部向下递减,且在冠层上中部递减迅速,下部递减缓慢;平均PAR透光率随施氮量的增加而递减;平均PAR透光率日变化表现为早晚较低,中午较高;平均PAR透光率随向下累积LAI的增加呈指数递减,群体消光系数K的日变化表现为早晚较高,中午较低,灌浆期的K值介于0.35～0.50.水稻冠层内PAR的三维空间分布表现为冠层上中部水平面上PAR透光率高,光斑面积大;下部水平面上PAR透光率低,光斑少;同一冠层高度水平面上的PAR光强呈不均匀分布.株型紧凑的水稻品种,冠层透光率高,透光率日变化大,群体消光系数小.Field experiments were conducted in Nanjing in 2007 and 2008,involving two rice cultivars and three nitrogen application rates.The plant morphology and spatiotemporal distribution of PAR at different canopy heights were measured at filling stage with SunScan canopy analysis system.Nitrogen application rate had significant effects on the plant height,panicle curvature,and leaf angle of rice.The leaf area was greater in mid canopy than in upper and basal canopy.The maximum leaf area index（LAI） layer appeared at 0.60 of relative canopy height.The average PAR transmittance decreased from top to bottom in rice canopy,exhibiting a quick attenuation within the upper and mid canopy and a slow reduction within the basal canopy.In addition,the average PAR transmittance at different canopy heights decreased with increasing nitrogen application rate.The diurnal variation of average PAR transmittance was greater at noon than in the morning and afternoon.With increasing LAI accumulation,the average PAR transmittance at different canopy heights decreased in an exponential pattern.The diurnal variation of population extinction coefficient（K） was smaller at noon than in the morning and afternoon,and the K value was in the range of 0.35 -0.50.The 3-dimensional distribution of PAR in rice canopy indicated that the PAR transmittance on horizontal plane was greater,and exhibited much more light flecks in upper and mid canopy than in basal canopy.The PAR density distribution at the same canopy height was non-uniform on the horizontal plane.Higher PAR transmittance,greater diurnal variation of PAR transmittance,and smaller population extinction coefficient were observed for the erect plant type rice cultivar.

关 键 词：水稻 光分布 透光率 光合有效辐射 消光系数 

分 类 号：S511[农业科学—作物学]