Mapping Variations in Corn Growth in a Rain-Fed Crop Field using Growing Season NDVI and NDMI Images

Abstract. Relying on spring and summer rainfall, numerous Illinois farmers grow corn and soybeans. As a result, farmers cannot precisely manage their crops’ water intake and are interested in monitoring crop growth and uniformity within each field. Using Landsat-derived Normalized Difference Vegetation Index (NDVI) and Normalized Difference Moisture Index (NDMI) images distributed by the US Geological Survey for the 2023 growing season growth in a 29.2-hectare field planted to corn and a 93.5-hectare field planted to soybeans were monitored. Visual and spectral analyses of the NDVI and NDMI images revealed that variations in crop growth were related to changes in elevation, which corresponded to the water holding capacity at higher and lower elevations. The NDVI and NDMI images identified the repairs done to a tile in spring 2023 as well as wet and nonproductive areas within the fields.