A non-standard combination of spectral bands from Landsat Thematic Mapper that include shortwave infrared (SWIR) measurements set the unusual color tones of green and purple of this Thematic Mapper image collected by Landsat over the semi-arid Western Great Plains. Blue tones designate bare soil, greens native vegetation and grasslands, purple and yellow indicate crops in various stages of development. Successful cultivation depends on special agricultural practices. Circular patterns indicate use of pivot irrigation systems. Fields plowed in strips are left to fallow every other year to fix soil nutrients. (Data courtesy Veridian ERIM International)