Agricultural, a.
Of or pertaining to agriculture; connected with, or engaged in, tillage; as, the agricultural class; agricultural implements, wages, etc. -- Ag`ri*cul"tur*al*ly, adv. Agricultural ant (Zoöl.), a species of ant which gathers and stores seeds of grasses, for food. The remarkable species (Myrmica barbata) found in Texas clears circular areas and carefully cultivates its favorite grain, known as ant rice.
Shades of meaning
Fernald has no entry of its own for agricultural; he lists it under rustic.
Where he writes about it:
Agriculture is the generic term, including at once the science, the art, and the process of supplying human wants by raising the products of the soil, and by the associated industries; farming is the practise of agriculture as a business; there may be theoretical agriculture, but not theoretical farming; we speak of the science of agriculture, the business of farming; scientific agriculture may be wholly in books; scientific farming is practised upon the land; we say an agricultural college rather than a college of farming. — from agriculture