Hans Peter Broedel
During the late Roman Empire, agricultural production had been focused largely on the great estates of powerful aristocrats. Known as latifundia, these plantations were typically specialized, producing whatever might generate the highest profits for their owners, but they were also not very productive. Roman agriculture was “extensive,” meaning that it required relatively little labor or other resources, and relied on sheer size to compensate for low yields. Slaves or impoverished tenant farmers worked these farms, with little investment in their success or failure. With the collapse of Roman administration in Europe, however, and the arrival of new German landlords in the early Middle Ages, this system was gradually replaced with smallholdings – self-sufficient family farms. These employed intensive agriculture in which labor, fertilizer, and other techniques enhanced productivity. This, along with the fact that many of these farmers were now free and therefore more personally invested in how well their farms did or did not do, made farmers receptive to agricultural innovation, and early medieval peasants embraced technologies that had either been unknown to the Romans or previously underutilized.1
The so-called heavy plow provides an excellent and important example of this process. Roman farmers used a lightweight scratch plow called an ard ; this was basically just a pointed stick that was drawn through the soil to create a shallow, narrow furrow for planting. This worked well enough in the light, dry, sandy soils of the Mediterranean, but much less well in the dense, wet, clay soils common in Northern Europe.
In contrast, the heavy plow was both massive and complicated; its simplest version consisted of a sharp coulter to cut into the soil and a trailing iron ploughshare and wooden moldboard. This plow dug a deep furrow and turned over the soil, burying weeds, enhancing fertilization and improving drainage.2 Exactly where the components of this plow originated is hard to say, but the fully developed European heavy wheeled plow was almost certainly the work of European farmers, who were experimenting with different plow configurations at least as early as the seventh century. A relevant and lasting consequence of Charlemagne’s empire was that new ideas and techniques passed easily from place to place, and by the year 1000, the heavy plow in various forms had become common throughout Europe.3
As is so often the case, one technological change begets others. Because the new plow was extremely heavy, it required a team of as many as eight oxen to draw it. When added to the already considerable cost of the plow, this meant that economics encouraged or even required peasants to work together and pool their resources in order to plow the fields efficiently. On one hand, this increased productivity because animal power was replacing human labor; on the other hand, however, it also encouraged lords to impose a common set of obligatio