Monitoring wheat main growth parameters at anthesis stage by Landsat TM

In order to acquire detail information of a regional winter wheat within growth season to instruct the production, the experiment was carried out in wheat growth season during 2007-2009 in Jiangsu province to monitor main growth parameters with Landsat TM data. The relationships of main growth parameters, grain quality and yield parameters at anthesis stage were analyzed, as well as the relationships of main growth parameters with satellite remote sensing variables. And then the quantitative relationship models were established and evaluated to monitor SPAD, biomass, leaf area index (LAI) and leaf nitrogen content(LNC) in winter wheat using remote sensing spectral variables derived from Landsat TM images. The results showed that at anthesis stage, it was feasible to monitor wheat SPAD, biomass, LAI and LNC using the satellite remote sensing variables of nitrogenous reflection index (NRI), B4 and normalized difference vegetation index (NDVI) respectively. Based on sensitive remote sensing variables, the models for monitoring SPAD, biomass, LAI and LNC at anthesis stage in winter wheat were established, which the root mean square error (RMSE) for SPAD, biomass, LAI and LNC were 3.12, 216.5 kg/hm2, 0.269 and 0.162, respectively. Based on the monitoring models, the thematic mapping of monitoring SPAD, biomass, LAI and LNC under different grades at anthesis stage can be got to realize the spatial quantization expression for monitoring main growth parameters. The technology to obtain large area information using satellite remote sensing data can overcome the shortcoming of point sampling technology, and provide timely informations for agricultural production management decisions.