【摘要】 为研究作物生长发育早期受干旱影响的作物水分光谱特征,对冬小麦返青期进行水分控制试验。利用野外光谱辐射仪在河北固城试验区测量冬小麦的光谱并分别计算归一化水分指数(NDWI)和简单比值水分指数(SRWI),同时测定冬小麦的叶绿素浓度(Chl)、叶面积指数(LAI)、株高(H)和叶片相对含水率(LRWC)等冠层生理指标和土壤湿度(SM)。分析结果表明:冬小麦生理指标与土壤湿度之间有着显著的正相关,最大相关系数为0.657,表明土壤水分状况直接影响作物发育早期的光合和生长状况。NDWI/SRWI与SM相关系数均为0.545,呈现弱的正相关;相反,水分指数与冬小麦生理指标之间的相关不明显,特别是,NDWI/SRWI与LRWC的相关系数仅为0.175。据此得出在作物低覆盖生长阶段,水分指数更多反映的是土壤水分状况而不是作物水分。更多还原

【Abstract】 The controlling experiment of soil moisture was carried out for the study of crop water spectral features affected by the drought in crop early growth and development stages.The spectra of winter wheat were measured using field spectral radiometer in Gucheng Experiment Station of Heibei Province,and normalized difference water index (NDWI)and simple radio water index(SRWI)were calculated,respectively.Meanwhile,the canopy physiological indexes including chlorophyll concentration(Chl),leaf area index(LAI),plant height(H),leaf relative water content (LRWC)and soil moisture(SM)were measured.The results show that there were significant correlations between canopy physiological indexes of winter wheat and SM,the largest correlation coefficient is 0.657,which indicated that crop early photosynthetic and growth were directly affected by the soil moisture.The correlation coefficient is 0.545 among NDWI/SRWI and SM,which show a weak correlation;whereas,there are not obvious between physiological indexes of winter wheat and WI;especially,the correlation coefficient is just equal to 0.175 among NDWI/SRWI and LRWC.The conclusion was that the water index implied the soil moisture condition instead of crop water content in the low coverage crop growing period.更多还原