The Oneco series consists of well and moderately well drained soils formed in loess, glacial till, and material weathered from limestone bedrock on uplands.
Permeability is moderate in the loess and till and slow in the residuum.
Slope gradients range from 1 to 12 percent. Mean annual temperature is about 48 degrees F. and mean annual precipitation is about 33 inches. Oneco silt loam. The solum commonly is 40 to 50 inches thick but ranges to 60 inches. The loess typically is 10 to 15 inches thick and the glacial till is from 25 to 40 inches thick and their combined thickness is about 36 to 50 inches.