The Agriculture domain was created by Malbrig, which he subsequently shared with the other gods when he passed from the world (3307). Gods who entered the world since then have not been given access yet.
As the god of Agriculture, one promotes the growth of cultivated plants specifically. Farm produce is the concern of this domain, along with orchards and other plants that serve mortals.
Farmers and any who rely on tended soil say prayers to the gods of Agriculture, particularly at times of planting and harvesting.