CAJ | 학술논문

通过田间试验研究了玉米不同生长期冠层光谱反射率的变化特征,分析了不同施氮水平下可见光区冠层光谱反射率的差异.研究结果表明:受作物群体光和能力的影响,玉米可见光区冠层反射光谱在拔节期达最高点,随后持续降低;近红外区,苗期反射率最低,在拔节期达最高点,喇叭日期有所降低而在开花叶丝期得到回升,进入灌浆期后义下降.不同施氮水平下,拔节期随施氮水平的增加,叶绿素的强吸收带(430～450和640～660 nm)玉米冠层反射曲线呈下降排列,但在550 nm附近反射率R_(正常)＞R_(偏低)＞R_(偏高);喇叭日期偏低施氮区的冠层反射率在可见光区明显高于其它施氮水平,且偏高和正常施氮区域内光谱反射强度基本相同,显示过量施肥并不会促进作物生长.分析玉米生长期间不同施氮水平下光谱反射率的差异,对监测玉米生长状况,指导田间施肥具有重要的现实意义.
통과전간시험연구료옥미불동생장기관층광보반사솔적변화특정,분석료불동시담수평하가견광구관층광보반사솔적차이.연구결과표명:수작물군체광화능력적영향,옥미가견광구관층반사광보재발절기체최고점,수후지속강저;근홍외구,묘기반사솔최저,재발절기체최고점,나팔일기유소강저이재개화협사기득도회승,진입관장기후의하강.불동시담수평하,발절기수시담수평적증가,협록소적강흡수대(430～450화640～660 nm)옥미관층반사곡선정하강배렬,단재550 nm부근반사솔R_(정상)＞R_(편저)＞R_(편고);나팔일기편저시담구적관층반사솔재가견광구명현고우기타시담수평,차편고화정상시담구역내광보반사강도기본상동,현시과량시비병불회촉진작물생장.분석옥미생장기간불동시담수평하광보반사솔적차이,대감측옥미생장상황,지도전간시비구유중요적현실의의.
The canopy spectral reflectance and chlorophyll content of corn were measured and analyzed under different nitrogen treatments.The trends of chlorophyll content were discussed based on different growth stages and different nitrogen levels.It was observed that the chlorophyll content increased with the increase in nitrogen,and could be affected by the environment changes including the temperature,rain,fertilizer treatment and so on.The characteristics of canopy spectral reflectance indicated that the canopy spectral reflectance changed significantly at different stages.In the visible region (400-750 nm),the reflectance increased and reached the maximum until the shooting stage,and decreased subsequently with the growth progress.In near-infrared region (750-1 000 nm),the spectral reflectance climbed sharply.It increased from tillering stage to shooting stage first,and then began to decline at trumpet stage and was raised again at anthesis-silking stage.At milking stage,the reflectance was decreased again.There were clear distinctions of visible reflectance in different nitrogen regions.At shooting stage,with the increase in nitrogen the reflectance decreased at chlorophyll absorption hand (430-450 nm,640-660nm).Investigating the reflectance of the corn canopy under the different nitrogen treatment,it was found that the reflectance was higher in normal fertilizing region than others in 550 nm,with R_(Normal)＞R_(Low)＞R_(High).At trumpet stage,the canopy reflectance in low fertilizing region was higher than others in the visible region.It was clear that the corn canopy reflectance of normal fertilizing region was the same as high fertilizing region.The results indicated over fertilizing could not help increase the corn nitrogen uptake.The study provided the basic information of chlorophyll measurement based on spectral technology and could help to guide the precision fertilizer in the field