Tillage information is crucial in environmental modeling as it has a direct
impact on sediment delivery, phosphorus loss, and water holding capacity o
f agricultural soils. Remote sensing techniques can provide information abo
ut tillage practices over large areas. In this study, six Thematic Mapper (
TM)-based logistic regression models proposed by van Deventer et dl. (1997)
were used to distinguish conventional and conservation tillage practices i
n the Lower Minnesota River watershed located in southern Minnesota. Accura
cy assessments of tillage maps derived from Landsat TM data were made using
field data collected by the Natural Resources Conservation Service (NRCS).
Regression models were easy to use, cost and time effective and produced r
easonably accurate tillage maps. The "percentage correct" and kappa (k) val
ues varied from 42-77% and 0.03-0.51, respectively, with best values for lo
gistic regression models that use TM band 5 or the difference between TM ba
nds 3 and 5 images. This approach is promising for the rapid collection of
tillage information on individual fields over large areas.