Elk City, Okla., no-tiller Spencer Smith (left) and father Jimmy discuss the formation of 4Ag Mfg. and the science behind the new gauge-wheel tires they’re making that stand up to stubble and stalk damage and prevent mud accumulation. The Smiths no-till mostly cotton in western Oklahoma and worked with the late Danny Davis, who also no-tilled cotton, and machinist Jake Hunter to create the new tires.