Armstrong and Lamoni soils formed in paleosols and have 2 chroma Fe depletions within 10 inches of the top of the argillic horizon. Pershing soils formed in loess and have 2 chroma Fe depletions within 10 inches of the top of the argillic horizon. These soils are higher on the slope than Purdin soils. Moderately well drained. Runoff is medium to rapid.
Permeability is slow.
A perched water table has an upper limit of 2.0 to 3.5 feet during November to April. Most areas of Purdin soils are in grass or grass-legume pasture or hayland. A few areas are used for woodland, and some areas are used for wheat, corn, milo, and soybeans. Native vegetation is mixed hardwoods and prairie grasses. The Purdin series is moderately extensive.