Variation in Alluvial‐Derived Soils as Measured by Landsat Thematic Mapper

Abstract

Abstract Landsat thematic mapper (TM) data acquired over Mississippi County, Ark. were evaluated in order to determine the sensitivity of TM to soil properties under growing soybeans [ Glycine max (L.) Merr.], and to determine whether or not established soil survey soil association boundaries were apparent on TM imagery of cropped fields. Ten fields of soybeans at the same growth stage were selected such that five fields had complex soil patterns and five fields had uniform soil patterns for the sensitivity evaluation. A detailed soil survey was available for the area. Landsat TM has six narrow spectral bands with 30 m ground resolution and a broad thermal band with 120 m ground resolution. While all bands provided useful information, the 0.76 to 0.90 µm (band 4), the 1.55 to 1.75 µm (band 5), and the 10.4 to 12.5 µm (band 6) were most useful in identifying soil association boundaries located by the USDA‐SCS general soil maps. Examination of the digital values of the individual TM bands indicated that the coefficients of variations increased as the within‐field variability of the soils increased for all TM bands; TM appears to provide information of within‐field variability related to soil differences and as reflected by the vegetation growing on the soil.