Monday, July 15, 2019

Moldboard Plows and Medieval Agriculture

(Author's note: this is so nerdy that I hesitated to post it when I wrote it last week, but, well, here it is. If you don't want too learn about manure management stop now.)

I was reading Peter Wells' Barbarians to Angels (2008), a book arguing that the early Middle Ages were anything but Dark, and he says this:
Of fundamental importance was the development of a new technology of agriculture — the moldboard plow — which vastly increased the efficiency of food production beyond anything in Roman times. This new technology meant that fewer people could produce larger harvests than was possible earlier, thereby releasing many former farmers to work in other, specialized, activities such as manufacturing, trade, and building. (11)

Other technological improvements also contributed to making food production more efficient. The development of the horse collar allowed this faster and stronger animal to replace oxen on some farms as the draft animal pulling the plow. The introduction of the three-field system increased agricultural yields. . . . These three changes — the moldboard plow, the horse collar, and the three-field system — enabled farmers to feel their communities at an unprecedented level of efficiency. (132)
I have been reading statements like these since I was in high school and I have long wondered how they could be true. Did the Roman empire really feed 60 million people with inferior plows and no crop rotation? Roman Gaul had at least as many inhabitants as the France of 1200 AD, and its towns were probably larger; how were all those people fed? Plus, the ancient Romans were obsessed with agriculture, which along with war and politics was the only suitable employment for a gentleman, and they left us a rich legacy of detailed treatises on how to manage an estate. Can the technically marvelous Romans, whose bridges still stand in the hundreds, really have been that ignorant about farming, the art they loved the most?

I looked into this problem several years ago but never had any reason to write about it, until Peter Wells inspired me to dive back in. If the experts on Roman agriculture are right, what Wells says, and what all the other textbooks that repeat the same line say, is nonsense. Roman agriculture was actually more intensive and productive than anything practiced in the Middle Ages, and in fact some authorities say the western Europeans did not exceed Roman productivity until after 1850. Here is a fairly typical sample of contemporary writing on Roman agriculture:
The best informed authorities have long acknowledged that Roman farming was both sophisticated and productive, with clear evidence that the ancients had anticipated the critical innovations most responsible for the modern agricultural revolution: seed selection; effective tillage; hoeing and harrowing to destroy weeds; crop rotations; the suppression of bare fallow; the rotation of legumes, whether for human consumption, fodder or green manure; irrigation, particularly of meadows and garden vegetables; artificial leys sown with leguminous fodder crops; housing of livestock; improved manure management; careful grazing management for range and pasture land; and, most decisively, as I have argued in a number of publications, ley farming or convertible husbandry, still the most effective system of intensive mixed farming. . . .

Within the highly urbanized and affluent heartland of the Roman empire, our sources and archaeological evidence present a coherent picture of market-oriented intensive mixed farming, viticulture, arboriculture and market gardening, comparable, and often superior, in its productivity and agronomic expertise to the best agricultural practice of England, the Low Countries, France (wine), and Northern Italy in the mid 19th century. GrecoRoman farmers supplied a large urban population equal to, if not significantly greater than, that of early 19th century Italy and Greece, with a diet rich, not just in cereals, but in meat, wine, olive oil, fish, condiments, fresh fruit and vegetables.
If you have read much about modern organic farming you have probably seen ancient Roman works on farming cited approvingly; one gardening book I read noted that using methods described by Columella (c 70 AD) organic vineyards can equal the yields of more "modern" operations, and in a more sustainable way.

There are two sources of confusion here. One is that the Romans lived around the Mediterranean, and all of their expertise concerned farming in that environment. Northern Europe was another world. Especially on the heavy clay soils that dominate around around the North Sea, very different farming methods were required to get good yields. Peter Wells is an expert on Northern Europe, and that is also the focus of most American textbooks. As near as I can tell the improvements they are writing about were things necessary to bring the agriculture of England, the Low Countries, northern Germany, and Denmark up to Mediterranean standards. In that environment these methods have been very successful, and by the 1600s the Netherlands may have surpassed Valencia or the Po Valley as the most productive farming region in Europe.

The other has to do with the different kinds of agriculture practiced in the Classical world, which have parallels wherever people farm. There were vast areas of the Mediterranean zone where people practiced low-intensity, fairly primitive agriculture. These were places without enough water, from either rainfall or irrigation, to sustain intensive farming, and where there were not urban markets or ports close enough to make commercial farming viable. In those regions people alternated wheat and bean crops with sheep grazing in a loose, long-rotation system, which is not very efficient. Really intensive farming was limited to places with enough water for year-round plant growth and nearby markets where the surplus could be sold. Yet even in remote places the Roman economy led to changes; under the Empire more and more dry wheat and sheep land was converted to olive groves, which we can tell from the vast proliferation of olive presses on Roman archaeological sites (above).

Until 19th-century farmers began fertilizing with guano mined from Pacific islands, intensive farming required manure. It could be practiced only where there was a sufficient density of animals and people to created the requisite dung. With enough water, dung and attention, yields per acre could be boosted ten- or twenty-fold. But that was expensive and could only be profitable where there were nearby markets. Traditional agriculture could therefore get into a virtuous cycle with urban populations: more people meant more dung and higher crop prices, which meant more effort could be put into intensive farming, supporting higher populations. This happened in ancient Egypt, Italy and other favored locations; during the Middle Ages it happened in the Low Countries and around Paris and London. Part of the increase in productivity noted by historians of northern Europe came, not from new methods, but from population increase and the rise of urban markets that made it profitable for farmers to work their land more intensively.

This also explains how some parts of the Classical world came to have such primitive agriculture in more recent times. Especially in Greece and Sicily 19th-century travelers marveled at the primitive farming methods they saw and rhapsodized about peasants whose lives had been unchanged since the dawn of time. The more astute puzzled over how ancient Athens or Syracuse could have been sustained that way. The real story is that in some areas that virtuous cycle was broken: the towns were sacked and abandoned, which tanked the markets and cut off the supply of night soil, so the farmers reverted to subsistence methods that required less investment of money and labor; without profitable work, many people moved away to more prosperous regions.

In conclusion, the history of agriculture is vastly more complex than anything your textbooks told you, which should make you question everything else your textbooks told you about technology, society, or economics.


Shadow said...

Good post. The things that move the world often aren't sexy.

JustPeachy said...

Oddly, this is not the first post I've read about manure management this morning-- it's a fascinating topic!

David said...

I would certainly agree that the history of agriculture is complex, and I too have wondered about that three-field etc. schtick. A problem, as you suggest, is that people make arguments about "Roman" and "medieval" agriculture when they're actually talking about regionally specialized and circumscribed developments. Wells and the people he's following have always been talking about northwestern Europe, and my impression is that the hyperbole about Roman productivity mainly applies to Italy, Egypt, and similar lands. By the same token, I'm skeptical of the argument that population, urbanization, and productivity in Gaul didn't reach "Roman" levels until some late date--this may apply to the area within, say, 150 miles of the Mediterranean coast, but I'd be truly impressed if someone could prove this for Paris, Orleans, Picardy, Champagne, and other northern regions.

One theme is the way Mediterranean cities were perennially dependent, except perhaps in locally very, very good years, on grain imports. This was true in Roman, medieval, and early modern times, and by the latter period they were importing a lot of their grain from northern Europe, including places like Poland.

In all this there are small regional shifts: Valencia had a very good run in the 15th century, but before and after not so much; Catalonia had a good run in the 13th and early 14th centuries, and a bad downturn after that. So one can say, look at fifteenth-century Valencia, so productive--but that says something about Valencia at that time, not about Mediterranean agriculture, as a whole across centuries or millennia.

Were the Romans that technically marvelous? (Note, I can't tell whether you're being a bit tongue-in-cheek with this, but I'll proceed as if not.) Yes, compared to Europe under Charlemagne. What about Europe in 1300? Again, I'm skeptical. For one thing, it seems to me that interest on the part of Roman gentlemen, given the nature of Roman gentlemanly education, would have been more likely to have a retarding than a facilitating effect on technical advance. Based on my (admittedly secondary) knowledge, Roman military practice under the High Empire pretty much stagnated (partly because it continued to work very well, but partly Roman gentlemen were conservers, not tinkerers). The technology the imperial Romans excelled in was plumbing. Plumbing is vital--to paraphrase admiral Rickover, if I had to do without modern conveniences, modern plumbing is the last one I would willingly forgo--and medieval people were terrible at it. The high and late medievals, meanwhile, surged past the Romans in Atlantic and northern waters sailing, clocks and other mechanical things, metallurgy, technical military innovation, and, I suspect, animal husbandry.

I would suggest that part of the reason we have such a stereotype of the hide-bound Middle Ages, is because we've inherited the ferocious arguments of the day between the conservers and the frantic innovators--many of the latter clergy, and/or of high birth, and not Italian (just as moderns still tend to think of 13th-15th century culture as spiritual, unworldly, and fanciful-chivalric because we keep reading the protests of a small, hyper-pious minority against the worldliness of the vast majority of their contemporaries.)

pootrsox said...

Excellent points, David!

Re the Romans, especially the Republican, or pre-Empire, variety: They weren't much on innovation per se, but they were brilliant at adoption and adaption of ideas from other sources. E.g. the arch: Etruscan, but what the Romans did with it!! Now, I think concrete was their own invention, and led to the ability to use caissons or similar to build solid structures underwater, structures which in some parts of Europe still stand. And the Roman roads were also at least to some degree a Roman innovation.

About the agriculture I know bupkus!

John said...

@David - yes, it's true that in many areas Medieval people were more technically innovative than the Romans; I would not, though, necessarily agree that because the Romans were generally very conservative they did not innovate in some areas. It really looks like they made major advances in cultivating olives and grapes in the 100 BC to 100 AD period; certainly they vastly increased the number of olive oil presses all across their empire. The guy I quoted from thinks they made major advances in raising fodder crops for their animals ("ley farming").

Anyway the point I wanted to make is that medieval agriculture did not vault beyond Roman agriculture in productivity; so far as we can tell, nobody in the west beat the best classical agriculture until after 1750 and maybe 1850. In northern Europe the new methods allowed medieval people to equal Roman productivity, not surpass it.

David said...

Something made the northern European population, at some point long before 1750, and probably by 1300, grow much higher than it had been in Roman times. If the French agriculture of, say, 1700, was not more productive than the Roman, then why did France have a population (20 million) that was 1/3 the size of that of the whole Roman Empire at its height (60 million, as I understand it; I'm sure it's much subject to debate, but I'm skeptical that it reached, for example, 100 million)? How was Britain's population able to grow to 8-10 million?

I suppose it depends on what you mean by productivity. What do you mean?

Whatever one means by productivity, somehow you have to account for the enormous population growth in northern Europe after 1200 (in itself, a major fact of global history). Perhaps, if northern European agriculture couldn't beat the *best* Roman agriculture until 1850, then its *average* productivity was nevertheless greater than the Roman from long before that? Something was feeding all those Picards and Saxons, not to mention a million Londoners.

If we don't want to say that there were no Dark Ages--and I would agree with that--I think we also don't want to say that they lasted until the age of Aquinas, whatever one thinks of him, still less those of Locke or Bismarck.

szopen said...

Great post. I, too, was reading and took it as a gospel that medieval times meant advances in agriculture, so it was interesting to see another perspective on that.

John said...

Indeed the population of *Northern* Europe grew a lot, because agriculture got better there. Besides the things Wells talks about I think there must have been a lot of breeding for seeds better adapted to the colder, wetter climate and maybe lots of other stuff. So the total population of Europe could have grown because the population of the Northern half grew. But my understanding is that the population of Italy, Greece, Spain, southern France, and north Africa did not grow greater than the Roman population until after 1700 anyway.

I wonder what role the Atlantic cod fishery played in this? That I think was new in the later Middle Ages.


David said...

I too was wondering about the cod fisheries. I can imagine a world in which a series of close, empirical studies showed that fishing or something similar made the difference in northern Europe. Pending that, however, it seems important to me that government policy, popular conception and protest, and decisions about what to plant in early modern Europe all clearly assumed a grain-based diet, with bread as a virtual sine qua non of human life. And yes, I could imagine an argument that all that was pure culture, and they simply refused to admit that their lives really revolved around fish (or whatever); but, again, I'd need massive empirical evidence to convince me they were that deluded.

Until that happens, I guess I'm inclined simply to reject the argument that "no one in Europe surpassed Roman agriculture until 1750 or even 1850."