This data set represents the estimated percentage of the 1-km grid cell that is covered by or subject to the agricultural conservation practice (CP329 ), Conservation Tillage Systems (CTS) on agricultural land by county. Conservation Tillage Systems is described as "managing the amount, orientation and distribution of crop and other plant residues on the soil surface year-round, while growing crops in narrow slots, or tilled or residue free strips in soil previously untilled by full-width inversion implements." (U.S. Department of Agriculture, 1995) This data set was created with geographic information systems (GIS) and database management tools. The acres on which CTS's are applied were totaled at the county level in the tabular NRI database and then apportioned to a raster coverage of agricultural land within the county based on the Enhanced National Land Cover Dataset (NLCDe) 1-kilometer resolution land cover grids (Nakagaki, 2003). Federal land is not considered in this analysis because NRI does not record information on those lands.