Agriculture is one of the main users of fossil fuels in our society. As fossil fuels decline, food prices will increase. How can we plant and harvest crops without fossil-fueled equipment?
Ugo Bardi, et al., discuss the use of renewable energy on a farm and possible solutions in their paper “Turning electricity into food: the role of renewable energy in the future of agriculture” Journal of Cleaner Production 53 (2013) 224-231.
They do not propose to use biofuels to run agricultural equipment for many reasons (see their paper or read “Peak Soil”).
What is proposed is battery-driven equipment recharged from a local or national grid — small equipment, since batteries are heavy and have limited range.
This paper makes the case that we need to start weaning agriculture off of fossil fuels now. If we wait too long, the financial resources to make a rapid conversion may not be available. Bardi also foresees a day when all farms will have to be organic, since we have no way of making pesticides from biomass.
Liebig’s law of the minimum
Crop growth is controlled by the scarcest resource, the limiting factor, not by the total amount of resources. Plants need sunlight, water, and 21 minerals.
Nitrogen is one of the most important mineral in short supply. The earth could support up to two billion people until nitrogen fertilizers were invented. Bardi believes these won’t be a problem because we can use renewable energy to operate the existing Haber-Bosch plants to make nitrogen.
The biggest problem is phosphates because their reserves are limited, and we’ve already mined the easiest and richest ores. Even if we converted phosphate mining vehicles to run on batteries, we’d still run out of phosphates to mine. Potassium, calcium, and magnesium need to be mined as well.
Water is another limiting factor. As we deplete aquifers like the Ogallala, food production will decline. Irrigation increased food production by 40% over the past 50 years. One hopeful solution Bardi mentions is that we can use windmills with gearboxes to pull water up from the remaining aquifers until they’re depleted (windmills in the past could only pull water up from 25 feet or less). Desalination uses far too much energy, it’s often unaffordable even for drinking water.
Pesticides, Herbicides, and Fungicides are made from and with oil
These toxins are made with fossil fuels as both the feedstock and the energy to produce them. There is no known way of making them from biomass. Because pests quickly adapted, we’re back to losing up to 40% of our crops just like in the past (and also poisoned the land), as well as disrupted natural parasite and predator populations to keep pests in check. This is yet another reason to make the transition to organic farming and permaculture now since we’ll have to anyway.
Farm Equipment – I don’t see how battery-run equipment would do much
Bardi points out that large electric vehicles aren’t possible because the weight of the batteries would be too large and the distance they could go is limited. So he proposes smaller vehicles.
The reason battery operated vehicles must be small, is that, per unit volume, a battery has only 3% of the energy as the same volume of oil.
John Deere makes row-crop tractors (8R/8RT Series) with 181 gallon tanks (686 liters). A tractor half that size with a 100 gallon tank, which is 3.75 x 2 x 2 feet (1.14 x .61 x .61 meters), would require a battery 33 times as large to deliver the same amount of power, or a 123 x 2 x 2 foot battery (37.5 x .61 x .61 meters)! (1)
Whatever farm equipment this paper proposes will be extremely limited in what tasks can be performed. They will have to be tiny and incapable of going very far.
Wouldn’t Horse Teams provide more power and fertilizer?
There’s limited time to plant or harvest grains. Even before fossil fuels, large farms had horse teams, sometimes with dozens of horses, to get this done quickly. If the sun isn’t shining or the wind blowing, how would you even charge the batteries?
I think it’s time to start breeding horses, mules, and donkeys plus set aside land for them to graze on. They’ll also fertilize the soil and add tilth for next year’s harvest. Since horses need water and at least 2 acres of land per horse, this may not be possible in many areas initially.
Let’s face it, no one wants to do brutal farm work, that’s one reason slavery exists. But there are kinder, gentler ways of farming. We need to go back to small-scale, family farms. John Jeavons has proposed clever land arrangements where 18 families live in a cluster that opens up to their half-acre of land. Using the bio-intensive methods he’s developed for over 25 years, a family would only have to work their land an average of 4 hours a day.
Industrialized agriculture is where we went wrong, and it can’t continue. We’ve mined the topsoil in many places to the point where we won’t be able to grow food — crops need six inches of soil. The best farmland in the world in Iowa, has been mined down from 18 inches to 9 inches in just a century from industrialized farming methods.
I don’t believe renewable energy can make a difference
Prieto & Hall recently showed that the EROI of solar PV arms in sunny Spain was at best 2.45 (with EROI of 12-13 required to run civilization as we know it). Other forms of renewable energy also have a low EROI. EROI can endlessly be argued over as proponents narrow the boundaries and life cycle while systems ecologists widen them.
But what’s indisputable is that rare earth and platinum group metals are finite, and require a great deal of fossil fuel energy to mine and process. Many critical metals come only from China or war-torn African nations, which adds supply chain failure to the mix. Solar, wind, hybrid cars, and batteries are heavily dependent on these scarce minerals. Making computer chips requires 60 minerals. Microprocessors are needed to manufacture and run battery-powered farm equipment
Renewable energy can’t last beyond fossil fuels. Electrified equipment requires fossil fuels throughout their life cycle, as well as to maintain them. Renewable energy components are transported over roads of concrete created with fossil fuel energy.
Bardi is right that we need to begin now to convert agriculture to less fossil fuel intensive methods, and has many hopeful and interesting ideas, but even he sees limits to growth (i.e. phosphates, depleted aquifers).
If it’s true there are no alternative energy resources that can replace fossil fuels, then Richard Heinberg’s “50 Million Farmers” is the solution society should be pursuing in earnest. Otherwise, rather than families who own their own land and will take good care of it, tens of millions of people will replace tractors on large industrial farms, and slavery will return.
Alice Friedemann www.energyskeptic.com
(1) Mike Kosanovich corrected my initial battery size — only one dimension of the 100 gallon tank should be multiplied by 33 to get the equivalent battery size. I appreciate corrections, thanks Mike!
References and additional reading
- John Opie Ogallala: Water for a Dry Land 2000
- Robert Glennon Water Follies: Groundwater Pumping & the Fate of America’s Fresh Waters 2004
- Sandra Postel Pillar of Sand, Can the Irrigation Miracle Last? 1999
- Vaclav Smil Enriching the Earth: Fritz Haber, Carl Bosch, and the Transformation of World Food Production 2000
- D. & M. Fisher The Nitrogen Bomb. April 2001. Discover magazine
- Gever, Kauffman, et al Beyond Oil: The Threat to Food and Fuel in the Coming Decades 1991
- Peter Golob Crop Post-Harvest Handbook Volume 1: Principles and Practice
- Eric Schlosser Fast Food Nation: The Dark Side of the All-American Meal 2002
- Michael Maren The Road to Hell The ravaging effects of foreign aid and international charity 2002
- Steven Stoll The Fruits of Natural Advantage: Making the Industrial Countryside in California 1998
- Richard Street Beasts of the Field. A Narrative History of California Farmworkers, 1769-1913. 2004
- Richard Walker The Conquest of Bread. 150 years of Agribusiness in California. 2004
- Julie Guthman Agrarian dreams. The paradox of organic farming in California 2004
- Kimbrell (editor) Fatal Harvest: The Tragedy of Industrial Agriculture 2002
- Jim Hightower Hard Tomatoes, Hard Times: A report of the Agribusiness Accountability Project on the Failure of America’s Land Grant College Complex 1978
- Carolyn Johnsen Raising a Stink: The Struggle over Factory Hog Farms in Nebraska 2003
- John Jeavons How to Grow More Vegetables: And Fruits, Nuts, Berries, Grains, and Other Crops Than You Ever Thought Possible on Less Land Than You Can Imagine
- Eleanor Agnew Back from the Land: How Young Americans Went to Nature in the 1970s and Why They Came Back 2005
- Jim Bender Future Harvest: Pesticide-Free Farming 1994
- B. C. Mollison Permaculture: A Designers’ Manual 1997
- Mildred Kalish Little Heathens. Hard times & high spirits on an Iowa Farm during the great depression. 2007
- M. R. Montgomery A Cow’s Life The Surprising History of Cattle
- David Masumoto Epitaph for a Peach, Four Seasons on my Family Farm
- Gene Logsdon The Contrary Farmer
- David Pimentel Food, Energy, and Society 1996
- Stephen Wegren Russia’s Food Policies and Globalization 2005
- Timothy Egan The worst hard time: the untold story of those who survived the Dust Bowl
- Steven Vogel Prime Mover: A Natural History of Muscle 2003
- Joanna Stratton Pioneer Women: Voices from the Kansas Frontier 1981
- Ann Greene Horses at Work: Harnessing Power in Industrial America 2008
- David W. Wolfe Tales from the Underground: A Natural History of Subterranean 2002
- R. Ratta, R. Lal Soil Quality and Soil Erosion 1998
- N. Brady, R. Weil The Nature and Properties of Soils 2001
Pesticides and other chemicals
- Theo Colborn Our Stolen Future: Are We Threatening Our Fertility, Intelligence, and Survival? A Scientific Detective Story 1996
Scarce minerals and other resources