Appalachian Plateau — smallest; low population; poor, thin soils; nickname: Plateau. Ridge and Valley — narrow bands; sparse to moderate population; mixed fertility in valleys; nickname: Valley ridges. Blue Ridge — mountainous; low population; acidic, thin soils (low fertility); nickname: North Georgia Mountains. Piedmont — mid-size; most populous (Atlanta metro); red clay loams, moderate fertility; nickname: The Fall Line / Piedmont. Coastal Plain — largest area; low-to-moderate population outside cities; fertile in river/lowland areas (historically plantation agriculture); nickname: Lowcountry.