Motor fuel, including kerosene, tractor fuel, liquefied petroleum gas, natural and artificial gas, diesel fuels, and distillate, when used for agricultural or railroad purposes, is exempt from the tax imposed by this chapter.
For the purposes of this section, agricultural purposes does not include the lighting or heating of any farm residence.
For the purposes of this section, railroad purposes includes only locomotives or track motor cars being operated on railroad tracks in road service in this state.
SDCL 10-45-19