Application of spatial analysis technology to quantifying leaf area of Medicago sativa plant based on GIS

An approach to measure the leave area of Medicago sativa was developed by using digital camera and GIS software in this study. Firstly, the pictures of M.sativa leaves were taken by the digital scanner; secondly, these pictures were vectored by R2V, and then data of perimeter and area were extracted from vectored pictures by GIS spatial analysis technology. The results of this study showed that average relative error of perimeter and area for extracted and actual values of reference were 0.177% and 1.68%, and were less than error range by leaf area apparatus (5%~15%). This study indicated that it was possible to measure leaf area of M.sativa by GIS spatial analyst technology. Compared to other methods of measuring leaf area, GIS spatial analyst technology had some merits with precision, simpleness, abundance, and could be extended in the fields of production and science research.