Monitoring Conservation Tillage via
Satellite By Sharon Durham April 24, 2008
To find out how much acreage is being farmed using conservation
tillage, Agricultural Research Service
(ARS) scientists have gone up high--to satellites.
G. Sullivan and
C. Strickland, in the ARS
Watershed Research Unit at Tifton, Ga., and Mark Masters, a resource
economist at the Albany State University
Water Policy Center in Albany, Ga., have created and evaluated conservation
tillage maps using Landsat TM 5 imagery. They report their findings in the
May/June issue of the Journal
of Soil and Water Conservation.
Conservation tillage is one of the nation's most widely adopted
conservation practices. It refers to any method of tillage that minimally
disturbs the soil surface, leaving at least 30 percent of crop residue cover
after planting. Conservation tillage has been credited with improving soil
quality, reducing runoff, and lowering fuel costs for farmers.
This satellite mapping technique shows promise for streamlining
national efforts to monitor changes in conservation tillage adoption over time,
evaluate the efficacy of conservation tillage placement, and reduce the need
for time-consuming field surveys to ensure compliance with federal cost-sharing
In 2004, an estimated 113 million acres of the nation's cropland were
in some form of conservation tillage. However, no national monitoring system is
in place to continue to monitor these efforts on a regular basis.
Using satellite imagery, Sullivan's team collected data over a
230,000-acre area centered on the Little River Experimental Watershed in
Tifton. It is one of the 14 designated national benchmark watersheds included
in the USDA Conservation
Effects Assessment Project-Watershed Assessment Study. Along with the
satellite data, researchers conducted a ground-based "windshield survey" that
identified 61 conservation tillage and 77 conventional tillage sites.
Results from this study provide a foundation to begin evaluating the
impacts of conservation tillage adoption and placement in the Little River
Experimental Watershed. Satellite-derived maps created during the study
directly contribute to a national effort to evaluate the results of federally
cost-shared conservation practices.
ARS is the U.S.
Department of Agriculture's (USDA) chief scientific research