Archaeologists working in eastern North America typically refer to precontact and early postcontact Native American maize-based agriculture as shifting or swidden. Based on a comparison with European agriculture, it is generally posited that the lack of plows, draft animals, and animal manure fertilization resulted in the rapid depletion of soil nitrogen. This required Indigenous farmers to move their fields frequently. In Northern Iroquoia, depletion of soil fertility is frequently cited as one reason why villages were moved to new locations every 20 to 40 years. Recent analysis of δ15N ratios of maize macrobotanical remains from Northern Iroquoia, however, suggests that Iroquoian farmers were able to maintain soil nitrogen in their maize fields. An expanded analysis of maize kernel δ15N ratios from three ancestral Mohawk villages indicates that farmers from those villages maintained soil nitrogen throughout the occupational spans of their villages. It further suggests that precontact Iroquoian agronomy was consistent with contemporary conservation agriculture practices.

In this article we present a comparative study of pig and cattle morphologies, and stable isotope analysis relating to pig demographic management at Levroux Les Arènes (Indre, France), to evaluate changes in husbandry practices between the Iron Age and the Roman period in Gallic societies. Results indicate the establishment of new production and distribution structures, probably before the second century bc, along with the implementation of a specific size/weight selection for the specialized production of pork. Pig and cattle size evolves progressively from the end of the third century bc. These changes are likely to be the result of an internal evolution within Gallic societies, based on local herds, but possibly they are a response to a broader changing economic climate. Within the Western Roman Empire, each province, and Italy, follows its own evolutionary pattern, which also differs between pig and cattle, suggesting that each region adapted its husbandry strategies according to its agro-pastoral characteristics, capacities, or ambitions.