Testing And Evaluation Of CGMD302 Crop Growth Monitoring And Diagnosis Instrument

The precise management of crop production is an important part of precision agriculture,the core thought is dynamic control,precision investment with the least amount of production inputs to produce to maximize production efficiency for crop group.Crop access to information and on-line diagnosis is the basis of precise crop management,which plays a decisive role to crop growth,quality,and yield.Based on canopy reflectance spectra,the information non-destructive monitoring techniques of crop growth is a key technology for the current precision management.Sensors as the perception of information equipment is the ways and means of access to the crop canopy spectral information.However,the current crop fertilizers and other crop growth information monitoring relies heavily on foreign imports spectrometer,and the remote sensing monitoring for crops,mainly is built based on a region a growth period of crop spectral characteristics and biological physical and chemical parameters of the model but is not yet using crop sensors in different ecological point,different nitrogen treatment,promotion test research of different varieties,which is difficult to effectively meet the needs of the precision of crop production management.The study was based on CGMD302 crop growth monitoring and diagnosis instrument for rice and wheat field test,and evaluated the performance of the instrument.Mainly to complete the following tasks:(1)Using CGMD302 crop growth monitoring and diagnosis instrument tested in Suzhou Wujiang,Jiangxi and Rugao,Xuzhou for different nitrogen levels of rice and wheat canopy spectra,the study found the size of the two-band reflectivity was R815>R730,and red band 730nm spectral reflectance with increasing nitrogen level decreases,and near-infrared spectral reflectance of the 815nm with increasing nitrogen levels on the rise.In the same band,under the same nitrogen treatment of varieties of rice and wheat canopy spectral reflectance there was no significant difference at 5%level.This study analysed the differences about the canopy reflectance of different kinds of rice and wheat with the changes of the growth period and nitrogen rates.Above results suggested that the differences of canopy reflectance about varieties between rice and wheat are great at near infrared flat(815nm)and weak at red edge(730nm).The vegetation indices of canopy reflectance about rice and wheat are increasing as the growth process gradually increased before heading period and got the maximum value,and then becoming decreasing after that period.This study also analysed the differences about the canopy reflectance of different nitrogen rates of rice and wheat with the changes of the growth period.Above results suggested that the the differences of canopy reflectance with increasing nitrogen rates between rice and wheat are great at near infrared flat(815nm)and got the most values at heading period.In contrary,the differences weak at red edge(730nm)and got the minimum value at heading period.The vegetation indices of canopy reflectance about rice and wheat are increasing with increasing nitrogen rates before heading period and got the maximum value,then becoming decreasing after that period.Show monitor contributes to the identification and classification of rice and wheat with different plant types and varieties of leaf color.(2)The regression coefficients between NDVI from rice canopy reflectance based on the CGMD302 and three growth parameter(LNC?LAI?LDW)could be calculated by the data of two rice field experiments in Wu Jiang(R2=0.7665,0.7918,0.8181).The regression coefficients between RVI,DVI and three growth parameter(LNC?LAI?LDW)are also produced(RVI:R2=0.7218,0.7799,0.8222,DVI:R2=0.6548,0.7849,0.8466).Then this study used the independent experiment from second year to test those models,and calculated the results about LNA,LDW,LAI between measured values and predicted values(RMSE=0.2635,0.0464,0.5554,RE=0.0943,0.1625,0.1012).Above results showed that the CGMD302 could monitor rice growth.(3)The regression coefficients between NDVI,RVI from rice canopy reflectance based on CGMD302 and four growth parameters(LNC?LNA?LAI?LDW)could be calculated by merging two rice field experiments in Jiang Xi and Wu Jiang(NDVI:R2=0.6497,0.8394,0.6964,0.7014,RVI:R2=0.6299,0.7477,0.6451,0.6858).This study divided the rice data from those two places into different plant type and analysed the relationship between growth parameter of different type rice and vegetation indices.The result shows that the coefficient of determination of growth parameter and NDVI is higher than that from different demonstration spots.However,the coefficient of determination of growth parameter and RVI is smaller than that from different demonstration spots.Above all,extracting different plant type data have application value and feasibility when calculating the monitoring model of different demonstration spots and suggest that CGMD302 has the ability to work in fields and to test more type of data.The study proved that CGMD302 have higher stability and accuracy.(4)This study then calculated the estimating model between two-band vegetation indices and crop growth parameter by the data from wheat field experiments in Rugao and Xuzhou,but also use independent experiments to test those models.The relationship about LNA,LDW,LAI between measured values and predicted values were calculated(R2=0.6382,0.763,0.7205,RMSE=0.7754,0.1309,0.7383,RE=0.3518,231413,0.1845).Those results suggested that CGMD302 performance well when estimating crop growth parameter,which provide technical and theory support for acquiring crop growth information quickly.