A political subdivision or a benefited district providing public services such as sewer, water, or lights or for nonfarm drainage shall not impose benefit assessments or special assessments on land used primarily for agricultural production within an agricultural area on the basis of frontage, acreage, or value, unless the benefit assessments or special assessments were imposed prior to the formation of the agricultural area, or unless the service is provided to the landowner on the same basis as others having the service.