Tillage
Image used under Public Domain License
Source: Lynn Betts / Photo courtesy of USDA Natural Resources Conservation Service
Tillage Before Crop Is Up
Image used under Public Domain License http://en.wikipedia.org/wiki/File:Fendt_Tractor_Ripping_up_Kulin.jpg Source: Ian Bailey
Tillage in Crop
Image used under CC BY http://en.wikipedia.org/wiki/File:Tractors_in_Potato_Field.jpg Source: NightThree
Tillage With No Crop
Image used under Public Domain http://commons.wikimedia.org/wiki/File:Discing_a_field_before_planting_flax_-_NARA_-_283918.jpg Source: U.S. National Archives and Records Administration