Abstract:

SPAD (Soil and Plant Analyzer Development) is known as the green leaves degrees,which means the parameters of leaf in relative chlorophyll content.SPAD is the important parameters of agronomy for assessing the winter wheat health condition.Therefore,crops in the farmland can be diagnosed and managed based on crop leaf chlorophyll content or SPAD.However,the traditional monitoring method is low efficient in monitoring the SPAD.This paper aims to integrate the field monitoring and remote sensing techniques in order to monitor the growth of winter wheat at Jianghan plain,China.The study was carried out at Houhu Management District of Qianjiang city,South China’s Jianghan Plain.At a winter wheat growth stage,the winter wheat canopy spectral reflectance and SPAD were monitored in field by using the ASD FieldSpec 3 and SPAD502.The Winter wheat spectroscopic monitoring were on a clear day or the breeze weather at time during 10〖DK〗∶00~14〖DK〗∶00.The monitor fiber was from the soil surface 120 cm.The ASD system cans automatically recorded 10 sampling information with its average as the spectral reflectance unobserved.This study randomly selected winter wheat leaves for monitoring SPAD in each period of winter wheat.This research combined the winter wheat growth period spectrum reflectance characteristics change,selected the four Hyperspectral Vegetation Index(GRVI,RVI,NDVI and DVI) with the winter wheat SPAD to build estimate model. Then the correlation between the Hyperspectral Vegetation Index (HVI) and SPAD was analyzed by SPSS.Four inversion models were constructed for estimating SPAD by using correlation analysis,regression analysis and other methods.The model tested NDVI accuracy,and found that NDVI was suitable for winter wheat SPAD inversion to the region.And then,it combined NDVISPAD inversion model and HJ1 remote sensing to monitoring winter wheat SPAD.By comparing HJ1 remote sensing with the field measured SPAD,the rootmeansquare error (RMSE) was 632.It is concluded that the research used differed scales from ground monitoring to remote sensing monitoring to the SPAD of winter wheat,and this is proved to be an effective method and technology