Estimation of Leaf Area Index of Maize by Vegetation Indices Extracted from Satellite Imaging

Leaf area index is an important parameter in controlling different processes between atmosphere-plant-soil and due to its importance in various modeling, its rapid measurement at different scales has been considered. The use of vegetation indices (VIs) is one of the common methods for estimation leaf area index and each of these indices shows different sensitivities in various values of leaf area index during plant growth period. The aim of this study was to estimate leaf area index using Normalized Difference Vegetation Index (NDVI), Difference Vegetation Index (DVI), Weighted Difference Vegetation Index (WDVI), Soil Adjusted Vegetation Index (SAVI), Green Normalized Difference Vegetation Index (NDVIg), Normalized Difference Water Index (NDWI), Optimized Soil Adjusted Vegetation Index (OSAVI), Enhanced Vegetation Index (EVI), Wide Dynamic Range Vegetation Index (WDRVI) and Green Difference Vegetation Index (GDVI) and comparison with measured leaf area index during the growth period of maize under different crop densities and the application straw mulching during 2020 growing season in the Karaj. Based on the results, the sensitivity of vegetation indices to leaf area index weren't same at different growth stage and indices such as DVI, WDVI and GDVI at the initial growth stage and NDVIg, NDWI and EVI at the mid growth stage showed high sensivity to estimation of leaf area index. Finally, OSAVI index With R2, RMSE and average noise equivalent (NE) of 0.91, 0.98 (m2/m2) and 1.8, respectively, considered as the best index for leaf area index estimation.