Replacing diesel tractors with horses or oxen – what will that be like?

Preface.  Since fossil fuels are clearly finite, at some point increasing numbers of farmers with diesel vehicles and equipment will want to replace them with horses, which can do the work of six people.  Here’s what  energy expert Vaclav Smil has to say about that.

Alice Friedemann  author of “When Trucks Stop Running: Energy and the Future of Transportation”, 2015, Springer and “Crunch! Whole Grain Artisan Chips and Crackers”. Podcasts: Practical Prepping, KunstlerCast 253, KunstlerCast278, Peak Prosperity , XX2 report


Vaclav Smil. 2017. Energy and Civilization A History. MIT Press.

During the 1890s a dozen powerful American horses needed some 18 tonnes of oats and corn per year, about 80 times the total of food grain eaten by their master.

Only a few land-rich countries could provide so much feed. Feeding 12 horses would have required about 15 ha of farmland. An average U.S. farm had almost 60 ha of land in 1900, but only one-third of it was cropland. Clearly, even in the United States, only large grain growers could afford to keep a dozen or more working animals; the 1900 average was only three horses per farm.

Even in land-rich agricultures with extraordinary feed production capacities the substitution trend could not have continued much beyond the American achievements of the late 19th century. Heavy gang plows and combines took animal-drawn cultivation to its practical limit. Besides the burden of feeding large numbers of animals used for relatively short periods of field work, much labor had to go into stabling, cleaning, and shoeing the animals. Harnessing and guiding large horse teams were also logistical challenges. There was a clear need for a much more powerful prime mover—and it was soon introduced in the form of internal combustion engines.

The simplest way of transporting loads is to carry them. Where roads were absent people could often do better than animals: their weaker performance was often more than compensated for by flexibility in loading, unloading, moving on narrow paths, and scrambling uphill. Similarly, donkeys and mules with panniers were often preferred to horses: steadier on narrow paths, with harder hooves and lower water needs they were more resilient. The most efficient method of carrying is to place the load’s center of gravity above the carrier’s own center of gravity—but balancing a load is not always practical.

In relative terms, people were better carriers than animals. Typical loads were only about 30% of an animal’s weight (that is, mostly just 50–120 kg) on the level and 25% in the hills. Men aided by a wheel could move loads far surpassing their body weight. Recorded peaks are more than 150 kg in Chinese barrows where the load was centered right above the wheel’s axle.

The superiority of horses could be realized only with a combination of horseshoes and an efficient harness. Performance in land transport also depended on success in reducing friction and allowing higher speeds. The state of roads and the design of vehicles were thus two decisive factors. The differences in energy requirements between moving a load on a smooth, hard, dry road and on a loose, gravelly surface are enormous. In the first case a force of only about 30 kg is needed to wheel a 1 t load, the second instance would call for five times as much draft, and on sandy or muddy roads the multiple can be seven to ten times higher. Axle lubricants (tallow and plant oils) were used at least since the second millennium BCE.

The roads in ancient societies were mostly just soft tracks that seasonally turned into muddy ruts, or dusty trails.  Roads in continental Europe were in similarly bad shape, and coach horses harnessed in teams of four to six animals lasted on average less than three years.

The stabling of the animals in mews and the provision and storage of hay and straw made an enormous demand on urban space. At the end of Queen Victoria’s reign, London had some 300,000 horses. City planners in New York were thinking about setting aside a belt of suburban pastures to accommodate large herds of horses between the peak demands of rush-hour transport. The direct and indirect energy costs of urban horse-drawn transport—the growing of grain and hay, feeding and stabling the animals, grooming, shoeing, harnessing, driving, and removal of wastes to periurban market gardens—were among the largest items on the energy balance of the late 19th-century cities.

The importance of horses, both in cavalry units and harnessed to heavy wagons and field artillery, persisted in all major Western conflicts of the early modern era (1500–1800), as well in the epoch-defining Napoleonic Wars. Large armies projected far from their home base had to rely on animals to move their supplies: pack animals (donkeys, mules, horses, camels, llamas) were used in difficult terrain;

Opening the road to Russia to Napoleon: that is how Philip Paul, Comte de Ségur (1780–1873), one of Napoleon’s young generals and perhaps the most famous chronicler of the disastrous Russian invasion, described the Prussian contribution. By this treaty, Prussia agreed to furnish many goods: 22,046 tons of rye, 264 tons of rice, two million bottles of beer,  44,092 tons of wheat, 71,650 tons of straw, 38,581 tons of hay, six million bushels of oats, 44,000 oxen, 15,000 horses, 300,600 wagons with harness and drivers, each carrying a load of 1700 pounds; and finally, hospitals provided with everything necessary for 20,000 sick.

When in 1900 a Great Plains farmer held the reins of six large horses while plowing his wheat field, he controlled—with considerable physical exertion, perched on a steel seat, and often enveloped in dust—no more than 5 kW of animate power. A century later his great-grandson, sitting high above the ground in the air-conditioned comfort of his tractor cabin, controlled effortlessly more than 250 kW of diesel engine power.

The mechanization of field work has been the main reason behind the rising labor productivity rise and the reduction of agricultural populations: a strong early 20th-century Western horse worked at a rate equal to the labor of at least six men, but even early tractors had power equivalent to 15–20 heavy horses, and today’s most powerful machines working on Canadian prairies rate up to 575 horsepower.

American draft horses reached their highest number in 1915, at 21.4 million animals, but mule numbers peaked only in 1925 and 1926, at 5.9 millio.

Replacing the existing American field machinery by draft animals would require horse and mule stock at least ten times as large as its record numbers from the early 20th century. Some 300 Mha, or twice the total area of U.S. arable land, would be needed just to feed the animals, and masses of urbanites would have to leave the cities for farms.

In single-cropping regimes of northern Europe draft horses would do only 60–80 days of strenuous field work during the fall and spring plowing and the summer harvesting, but most of them were used extensively for transport. A typical working day ranged from just five hours for oxen in many African locations to more than ten hours for water buffaloes in Asian rice fields and for horses during European or North American grain harvests.

A typical draft is 15% of animal’s body weight but for horses it is up to 35% during brief exertions (about 2 kW) and even more during a few seconds of supreme effort (Collins and Caine 1926). The combination of large mass and relatively high speed makes horses the best draft animals, but most horses could not work steadily at the rate of one horsepower (745 W), and usually delivered between 500 and 850 W.

Horses are the most powerful draft animals. Unlike cattle, whose body mass is almost equally divided between the front and the rear, horses’ fronts are notably heavier than their rears (ratio of about 3:2), and so the pulling animal can take a better advantage of inertial motion than cattle. Except in heavy, wet soils, horses can work in fields steadily at speeds of around 1 m/s, easily 30–50% faster than oxen.

Horses also have better endurance (working 8–10 hours a day compared to 4–6 hours for cattle) and they live longer, and while both oxen and horses started working at 3–4 years of age, oxen lasted usually just for 8–10 years, while horses carried on commonly for 15–20 years.

A horse’s leg anatomy gives the animal a unique advantage by virtually eliminating the energy costs of standing. The horse has a very powerful suspensory ligament running down the back of the cannon bone and a pair of tendons (superficial and deep digital flexors) that can “lock” the limb without engaging muscles. This allows the animals to rest, even to doze, while standing, with hardly any metabolic cost, and to spend little energy while grazing. All other mammals need about 10% more energy when standing as compared to lying down.

Besides speeding up plowing and harvesting, animal labor also made it possible to lift large volumes of irrigation water from deeper wells. Animals were used to operate such food-processing machines as mills, grinders, and presses at rates far surpassing human capabilities. Relief from long hours of tiresome labor was no less important than the higher output rates, but more animal work required more cultivated land to grow feed crops.

In North America and in parts of Europe, the upkeep of horses at times claimed up to one-third of all agricultural area.

An average 19th-century European or American horses annual useful labor equal to about six working farmers, and the land used for its feeding (including all the nonworking animals) could have grown food for about six people. Strong, well-fed horses could perform tasks beyond human capacity and endurance.

American farmers were advised to feed their working horses 4.5 kg of oats and 4.5 kg of hay a day (Bailey 1908), which translates to about 120 M J/day. With an average power of 500 W, a horse would do about 11 MJ of useful work during six hours, and while an average male human would contribute less than 2 MJ, though he could not maintain steady exertion above 80 W and managed only brief peaks above 150 W, a horse could work steadily at 500 W and have brief peak pulls in excess of 1 kW, an effort that would require the exertions of a dozen men.

Horses could drag logs and pull out stumps when humans converted forests to cropland, break up rich prairie soils by deep plowing, or pull heavy machinery. There were additional energy costs of animal labor beyond maintaining a breeding herd and providing adequate feeding for field labor; these additional energy costs appeared above all in the making of harnesses and shoes and the stabling of the animals. But there were also additional benefits derived from the recycled manure and from milk, meat, and leather. Manure recycling has been important in all intensive traditional agricultures as the source of scarce nutrients and organic matter. In largely vegetarian societies, meat (including horsemeat in parts of Europe) and milk were valuable sources of perfect protein. Leather was used in making a large number of tools essential in farming and in traditional manufactures. And, of course, the animals were self-reproducing.

In Chinese cities, high shares of human waste (70–80%) were recycled. Similarly, by the 1650s virtually all of Edo’s (today’s Tokyo) human wastes were recycled (Tanaka 1998). But the usefulness of this practice is limited by the availability of such wastes and their low nutrient content, and the practice entails much repetitive, heavy labor. Even before storage and handling losses, the annual yield of human wastes averaged only about 3.3 kg N/capita (Smil 1983). The collection, storage, and delivery of these wastes from cities to the surrounding countryside created large-scale malodorous industries, which even in Europe persisted for most of the 19th century before canalization was completed. Barles (2007) estimated that by 1869, Paris was generating annually about 4.2 Mt N, about 40% from horse manure and about 25% from human wastes;

The recycling of much more copious animal wastes—which involved cleaning of stalls and sties, liquid fermentation or composting of mixed wastes before field applications, and the transfer of wastes to fields—was even more time-consuming. And because most manures have only about 0.5% N, and pre-application and field losses of the nutrient had commonly added up to 60% of the initial content, massive applications of organic wastes were required to produce higher yields.

Every conceivable organic waste was used as a fertilizer in traditional farming: pigeon, goat, sheep, cattle, all other dung, composts made of straw, lupines, chaff, bean stalks, husks, and oak leaves.

Any theoretical estimates of nitrogen in recycled wastes are far removed from its eventual contribution. This is because of very high losses (mainly through ammonia volatilization and leaching into groundwater) between voiding, collection, composting, application, and eventual nitrogen uptake by crops. These losses, commonly of more than two-thirds of the initial nitrogen, further increased the need to apply enormous quantities of organic wastes. Consequently, in all intensive traditional agricultures, large shares of farm labor had to be devoted to the unappealing and heavy tasks of collecting, fermenting, transporting, and applying organic wastes.

Scale of traditional recycling (and hence the energies devoted to gathering, handling and applying the waste biomass) had to be so large because the organic materials applied to field or plowed in (as green manures) had very low nitrogen content: human and animal wastes are largely water, as are green manures; only oil cakes (residues after pressing edible oils) have relatively high nitrogen content. For comparison, urea, the leading modern synthetic fertilizer, contains 46% of nitrogen.

The performance of the best twine-binding harvester was soon surpassed with the introduction of the first horse-drawn combines, marketed by California’s Stockton Works during the 1880s. Housers, the company’s standard combines after 1886, cut two-thirds of California’s wheat by 1900, when more than 500 machines were working in the state’s fields. The largest ones needed up to 40 horses and could harvest a hectare of wheat in less than 40 minutes—but they tested the limits of animal-powered machinery because harnessing and guiding up to 40 horses was an enormous challenge.

At its beginning, a farmer (80 W) working in a field was aided by about 800 W of draft power (two oxen); by its end, a farmer combining his Californian wheat field had at his disposal 18,000 W (a team of 30 horses).

In 1800 New England farmers (seeding by hand, with ox-drawn wooden plows and brush harrows, sickles, and flails) needed 150–170 hours of labor to produce their wheat harvest. By 1900 in California, horse-drawn gang-plowing, spring-tooth harrowing, and combine harvesting could produce the same amount of wheat in less than nine hours. In 1800 New England farmers needed more than seven minutes to produce a kilogram of wheat, but less than half a minute was needed in California’s Central Valley in 1900, roughly a 20-fold labor productivity gain in a century.

Naturally, these huge advances were only partially due to much higher efficiencies resulting from better machinery. The other principal reason for the rapidly rising energy returns of human labor was the substitution of horse power for human muscles. American inventors produced a vast range of efficient implements and machines, but they had only limited success in displacing draft animals as farming prime movers.

During the first two decades of the twentieth century the numbers of American horses and mules stayed around 25 million. Growing enough feed for their maintenance and work required about one quarter of America’s cultivated land

In 1910 America had 24.2 million farm horses and mules (and only 1,000 small tractors); in 1918 the draft animal herd peaked at 26.7 million and the number of tractors rose to 85,000. With an average daily need of 4 kg of grain for working animals and 2 kg of concentrate feed for the rest, the annual feed requirements were roughly 30 Mt of oats and corn. With grain yields of about 1.5 t/ha, this would have required planting at least 20 Mha to feed grains. To supply roughage, working horses needed at least 4 kg/day of hay, while the rest could be maintained with about 2.5 kg/day, requiring an annual total of roughly 30 Mt of hay. With average hay yields of about 3 t/ha, at least 10 Mha of hay had to be harvested. Land devoted to horse feed had to be no less than about 30 Mha, compared to around 125 Mha of annually harvested land, which means that America’s farm horse herd (working and nonworking animals) required almost 25% of the country’s cultivated land. The USDA’s (1959) calculation came up with a nearly identical total of 29.1 Mha.

In early 19th-century Europe the typical ratio of human/animal power capacity rose to around 1:15, but on the most productive American farms it was well above 1:100 during the 1890s. Human labor became a negligible source of mechanical energy, and the value of farmers’ work shifted mostly to management and control, tasks of low-power needs but high-output rewards.


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10 Responses to Replacing diesel tractors with horses or oxen – what will that be like?

  1. Amarnath says:

    Up to 1960 I grew up in a village next to a town in South India.
    At least for 2000 years, bulls were used for plowing and grinding oil seeds. The saying goes, you can not interchange them as the latter go in circles. Although horses were around, they were used exclusively for transportation.
    One more piece of information. Throughout history palm leaves, cut to the size of a foot ruler, were used for writing. Engraving is done with a sharp nail. With that technology more than 2000 poems of ancient poets were preserved to this day.

  2. Sheila Chambers says:

    I would love to see how those believers in “renewables” can explain how solar panels & wind turbines which tap into a low density source of dispersed energy at an efficiency of only about 20% can replace energy dense fossil resource powered farm machinery to feed 7.6 BILLION humans?

    All they talk about is electricity for cars, homes & business but not a peep on how “renewables” can even begin to feed so dam many humans!
    Also not mentioned is how “renewables” can run our steel mills, glass works, heavy manufacturing, long haul trucking, mining or aluminum plants?

    After fossil resources become too difficult & expensive to extract, we will be forced to return to organic agriculture & are they in for a painful awakening!
    Having read the “farmers of 40 centuries” about the heavy labor China needed to feed themselves, I can see no way we can continue to feed our current population.
    This post emphasized just how much animal power & LAND it took to feed the less than 1 billion humans that existed before the industrial revolution, it also enlightens us to what the population might be after oil.

    The road between 7 billion down to 1 billion will be paved in blood & tears.
    When your fridge is as empty as your stomach, you won’t give a dam about your Tesla 3 or your solar panel powered home.

  3. A youtube trader has bought a salvage car, fixed it and re-sold it, making a profit of few hundreds dollars.

    The vblog is uploaded, cataloged, alerts sent to audience about it, and the digital platform is now streaming it non-stop.

    This is an abuse of finite, gold-grade, once only fossil fuels reserves, when thousands of digital servers, network devices, power plants and distribution stations working hard – all just to propagate the video 24/7 across the globe.

    The energy cost of the process is lakes, trains and tankers of fossil fuel supplies, all burned to cover for a youtuber who bought a car cheaply and sold it cheaply – making a $100 profit!

    This is Communism disguised Capitalism and fossil fuels are the sacrifice.

    Smil and his class of fine thinkers never explained why humans are so stupid, they either burn what remains of fossil fuels reserves in the air to the last drop, like no tomorrow, or default back to horses, poverty and pre-industrial conditions?

    Most of ‘Peak Oil’-interest blogging sites and channels are so committed nowadays to promote Collapse, forming a new class of Colapasist’s movement (/kəˈlapˈɪsɪsts/).

    – We either grow to 9 billion or default back to <1 billion in population in wars and self-destruction.

    – We either give every human in the developed world a 2+ tonne SUV or we default back to riding donkeys!

    – We either go to Mars or we keep intoxicating our environment on Earth, turning it inhabitable.

    – We either burn all remaining gold-grade fossil fuels to create solar, wind, nuclear, fusion, Tesla cars and Tesla batteries – that are either intermittent, experimental or resulting in polluting the environment so badly – or fossil fuels are so bad.

    We either burn all fossil fuels inventing Fusion, or we default to burn poos.

    Why these two extremes are pushed together hand by hand across the media and alternative media obsessively?

    Why humans don't work on an informed plan to downscale their energy consumption peacefully while fossil fuels are still around?

    Why humans don't acknowledge that to get excess energy, they need to expend several orders of magnitude more energy, upfront?

    Who still doesn’t believe that Adam Smith’s Invisible Hand of Economics and Huxley’s Over Organisation are 150 years ahead of the rest of humanity?!

    • Sheila Chambers says:

      IMHO, the reason we don’t act rationally about fossil RESOURCES is because most humans are STUPID!
      How else can we explain our irrational activities?
      Malthus warned us over a hundred years ago about overpopulation & the limits to food production but we refused to accept it, instead we believed in “HOLY” FAIRY TALES, “SUSTAINABLE” GROWTH, ABIOTIC OIL & “RENEWABLES” that are tied to the very RESOURCE we expect them to replace! DUH!!!
      Even worse if worse if possible, we are burning up this PRECIOUS, TEMPORARY RESOURCE AS FAST AS POSSIBLE!
      That’s why I am pessimistic about our future, we are still breeding like rabbits though some parts of the world have stopped growing, Africa’s population continues to grow mostly thanks to RELIGION.

      We still have “leaders” demanding that women have MORE CHILDREN, we still have “leaders” who are fighting to take away a womens right to her own body by forcing her to have children she does not want or can afford, the are fighting to again make abortion illegal so more women will DIE trying to remove a pregnancy they don’t want or a pregnancy that would endanger her life but to these MALE ANIMALS a womans life is of no value.
      We even have political MALE ANIMALS who are trying to pass a bill that would impose the DEATH PENALTY on abortion doctors & any woman who has an abortion!

      If the past is a guide to the future, I see a future of mass starvation, resource & border wars & runaway diseases because we refuse to accept science like evolution, the laws of physics & the FACT that there are LIMITS TO GROWTH!

      I would like to believe that we will stop the MADNESS of trying to support the endless GROWTH of our numbers, the endless GROWTH of the economy & that we will finally work to stop growth, give women the education & tools to control their fertility, to finally accept that we are ANIMALS & just one strand in the web of life & that we are related to every living thing on this planet & we cannot flourish on a dead planet. Like all animals, we must have a living ecosystem.

      We need to love something besides PROFIT, profit will be of no value when there is nothing to eat, when it’s too hot to work outside, when it’s so hot our crops wither in the field, when there are billions of desperate humans migrating in the futile hope of finding a better life, instead they will find only death.

      If we had truely been “wise” we wouldn’t be in the predicument we are in today.
      Instead we are foolish, shortsighted & STUPID!

      BTW, please don’t burn the poo, it will be needed to help fertilize the soil, that’s another STUPID ACTIVITY people do because their overpopulation has led them to cut down all the trees for fuel so their reduced to burning the very thing they need to help feed themselves, POO!

      • Malthus, as many others of his caliber, has failed to recognise that there is a minimum size of population and animals to exploit a piece of land fruitfully, yet alone the minimum size of population required to extract 100+ barrel of oil a day, billions of tonnes of coal a year and a balloon of natural gas as big as the atmosphere.

        This is despite Malthus was born at the peak of the steam engine and coal era.

        That size of population has now proved to be 7+ billion humans, by Physics!

        Now fossil fuels reserves are gone, the Colapasist’s (/kəˈlapˈɪsɪsts/) movement comes along, on the media and what is called ‘alternative media’, seeing the majority of humans a burden, and better to be eradicated.

        Like how “in 1918 the draft animal herd peaked at 26.7 million….” in the US alone, then went down in size after the wide scale usage of fossil fuels, Colapasists see the time has now come to reduce the number of humans, both men and women, too, even if through the agency of depopulation!

        Endless GROWTH” can simply be stopped immediately by leaving the Middle East and its resources alone, rather than keeping its nations under continuous bombardment – for resources – now since 1914.

        The video below shows how Russia is hard on bombarding Syria in the last couple of weeks. The news today that other international air forces have joined the carnival of killing, too!

        What “Endless GROWTH“? This is a genocide, indeed!

        • Sheila Chambers says:

          Appalling indeed but what’s a few thousand murdered civilians when compared to the 80 MILLION people added to the population each year?
          A mere drop in the bucket compaired to our GROWTH!
          Yes, we could quickly stop growth by simply cutting off the oil & letting billions of us die of starvation, disease & in resource wars.
          Billions of those starving will be migrating to a country near you with their hands out expecting us to take care of them, fat chance!
          People will do what ever it takes to survive, in the time of the black death when millions were starving, some even ate their CHILDREN rather than see them starve.
          We are in a nasty fix with no easy, kind, compassionate way out.

          WHY are the oil companies still working as hard as possible to EXTRACT OIL as quickly as possible?
          What is their plan for when they are no longer able to extract it in the amounts we now need?
          More wars?
          That seems to be our answer to all our problems, just bomb the hell out of it, what ever “it” is.
          That may not solve our “problems” but it sure as hell is PROFITABLE!

          • When money is printed, there is no more meaning for something called ‘PROFITABLE’.

            When money is printed, there is still a horrible meaning of killing innocent people.

            Killing people needs energy supplies to be expended in the process, including those supplies burned in justifying and fiercely promoting that killing on the web and other News channels – no matter how that effort appears fossil fuels energy-less, personal, innocent, volunteered and free of charge.

            Killing is killing, Murder is murder and Genocide is genocide – no matter how they are given different names or ill rationale.

  4. Bernard Beveridge says:

    I want to commend Shelia Chambers for formulating such a succinct summary of humanity’s predicament. For the life of me I cannot understand why so few people can see what is so patently obvious.

    • Sheila Chambers says:

      I don’t understand it either. I’m just a old “lady” with a poor public high school education who was stuck on the “mommy” track. After a while of reading science fiction, I finally ‘graduated’ to reading SCIENCE like evolution, astronomy, paleontology, geology, genetics, history & of course ecology.
      I’m not all that “smart” either but even I can see the road we persist in taking will lead to disaster.
      Perhaps being a “outsider” a social reject, never marrying or having children by choice, made it possible for me to see society in a different light. I also rejected religion at a early age, how can “smart” people believe in such nonsence?
      We could have done so much better than we had if we had been as wise as we named ourselves but being animals, we have animal instincts, we have male domenence, greed & stupidity ruling us, we have male animals willing to do the dirty work of corrupt “leaders” to keep the “masses” under control & keep the profits pouring in to the .01%.
      Look at our great architecture, our amazing works of art, our incredible technology then look at how we used & abused that knowledge.
      We could have lived in a paradice of our own making, a living, rich, ecosystem, everyone well fed, well educated, healthy & happy if it wasn’t for greed, irrational religions, shortsightedness & stupidity, things could have turned out so very different for us.

      Thank you Bernard Beveridge for your kind words, such kindness is rare these days.

  5. I too want to thank Sheila Chambers for her comments. I have seen them in other posts & they are clear & to the point & yes Bernard I too can’t understand how people can’t see the obvious.