You'll expect a sizable arable farming component, based on wheat, barley, some oats, probably still rye in areas with monastic influence. Rye was big in the Early Christian Period and associated with monasteries. Some peas and perhaps other crops as well. However, Ireland's farming economy has always been (since the start in the Early Neolithic c. 3800 BC) predominantly based on pastoral activity. You will expect a lot of grazing (cattle, sheep) throughout the country.