Very well written. Thank you. One hidden cost in the system is the reduced nutrient density of the crops grown in large scale agriculture operations. Food costs more but feeds your body less.
From my records our CSA required around 8 (uh oh) to 37(yikes!) kwh of energy to produce 1 kwh of food energy. Now around half of that was transport to get the food to customers doors but that did not include cooking! Of course farming for money without machinery means using unheated (that's a line I won't cross) greenhouses to produce high value labor intensive crops that tend to be light on calories and the 1000s of kwh in steel and electricity are cheap compared to the cost of 100s of kwh of the farmer's labor. I was still able to produce 1k to 1.5k food calories per hour spent working so if manual labor is around 350 calories an hour endeavor I wouldn't starve though I would need to account for the fact that you often have to spent more time in the kitchen then in the garden. Of course if it really came to it I would probably just irrigate an acre of sweet potatoes which only need some water and a deer fence and my calorie output ratio would skyrocket! That really is the problem with just looking at ratios though or maybe a farming under capitalism as a management exercise problem. Last year I was able to collect 21,000 calories of acorns to make flour for zero energy cost! (well I suppose except for the cost of remembering to bring a backpack on my walk) but a farm gate energy return of infinity doesn't really make sense either.
There is a reason for why vegetables were never a big share of food in almost any culture, especially not leafy vegs, tomatoes, cucumbers and peppers....Thanks for the figures!
"unheated (that's a line I won't cross) greenhouses"
I agree that heating a 3,600 sqft poly tunnel — even with two layers and a full-time fan separating them — is wasteful.
What we did in the winter was the "greenhouse in a greenhouse" technique. We put poly over some of our tables and added a small amount of electric heat.
One year, we had planted our Physalis late, and it hadn't borne fruit by first frost. We piled up greenhouse tables, put all the potted goldenberries in there, put a single, 60 watt incandescent bulb in the centre, and tightly covered the whole thing in plastic.
When we opened it in the spring, a few of the plants in the corners had frozen and died, but most of the plants were healthy — and the ground and greenhouse tables were littered with ripe goldenberries!
There are a lot of things one can do with a bit of tinkering. I have a small nursery with dubbel plastic (1.5 m2) inside a polytunnel, where I have electric floor heating for my chili and tomatoes when they are too big to keep inside and it is still to cold in the tunnel.
I found a bunch of baseboard heaters for free on CraigsList. I stripped the heating element out of them, put them under my greenhouse tables, covered them with (unfortunately) pink foam insulation, and plugged them into 120 VAC, which reduced their power by 75%. I then covered the tops of those tables with plastic.
Using this technique, I could start seeds in the high teens (°C) without the horribly expensive heating mats designed for the purpose.
I think I'm probably a little bit warmer in the winter, I can't start seeds, but a woven frost blanket to form a mini tunnel within a single layer poly tunnel will usually get the brassicas through the winter.
All of this just indicates we are in a collision course with reality. I have prepared well for our own fuel, our electricity wood for heat and food for us and animals. I started preparing about 50 years ago.Most of our energy comes from human work and the only flaw is my age at 76 years old but still working on the farm. Quite simple really.
I question your "double counting" of human energy, which I have seen you use in your other writings. It takes energy to access energy, whether it is using a diesel-fueled machine to dig coal out of the ground or growing potatoes by digging a trench with a shovel. Just because the farmer digging the trench eats his/her own potatoes does not mean you cannot count the energy input. It is a beneficial aspect of using food energy to grow food, but it does NOT mean it is double counting. The work requires energy. It depends on the use of the expended energy - not the work produced, but the energy actually used for that activity. You do not seem to be including the human labor as embedded energy either, so I don't see how you can conclude it is double counting. Nor are you using Odum's argument that human energy is somehow not the same "quality" as fossil fuel energy, which is just flat wrong. Heat is heat, as Clement and Carnot discovered 200 years ago.
As you know from my first book, I used 125 kcal/hour for input kilocalories for an overall estimate of 3000 hours per year. This includes sitting at the computer working on the farm spreadsheets, writing in the daily journal, driving to market, and sitting at the farm stand while waiting for customers, not just actual physical labor in the field. This is based on 2500 kcal/day in food fuel consumed, with 500 accounted for in 8 hours sleep. This leaves 2000 kcal for 16 hours in the rest of the day. The 3000 hours/year comes from life experience. I even checked this back when I was a market gardener by wearing my heart rate monitor all day long. The overall calorie usage was 125 kcal/hour. When I lived on a dairy farm in my youth, we easily put in 4000 hours a year per person and the dairy farmers I used to corroborate this number back in the decade of the 2000s agreed with me.
Now I am retired and don't have to think about business plans and marketing and all that. I write down my actual hours for work I do in the garden and use the rate of 200 kcal/hour. Last year I put in 598 hours and produced 3002 pounds of food (1365 kilos), with a calorie value of 855,000 kilocalories, or enough to feed .934 people. I don't even count all I harvested, as some crops are just too much trouble, are survival crops like sunchokes, or are only in small amounts or used to feed the birds, like strawberries and sunflowers. These are all rigorous numbers by the way, as I have been anal about numbers and data collection since I was a child.
The point here is that I calculate my inputs and outputs using standardized methods and assumptions. It is I who am doing the work and it takes energy to do so. It makes little difference if the fuel I use to do the work comes from the farm or the store. It takes energy to get energy. The key to an agricultural system is how efficient the energy use is. I note how one of the other commenters (bluejay) has figured out that their CSA program is in negative EROI territory. Mine wasn't, but most sustainable farmers in Whatcom County, Washington, where I used to live and work, were. This was because of their use of tractors, greenhouses, and driving to large urban markets. The upshot is that 25 miles from the farm is the tipping point for a market, even when you have a fuel-efficient vehicle and work yourself to a frazzle. (A person can get a lot done on just a bowl of potatoes or rice in a day. Plantation overseers knew this.)
I would like to know how you came to the conclusion that manual labor is double counting, even with your codicil of "in some cases." Thanks in advance.
Walter, I don't think it is right or wrong here, only different perspectives and purposes, which I also tried to explain, perhaps unsuccessfully.
I appreciate your meticulous recordn keeping and math!
If you want to determine if it makes energetic sense to farm at all, even for someone oriented to self-sufficiency (as opposed to foraging perhaps), the energy return on human labour is of course highly relevant. But then I believe you include all the food needed for fulltime workers and not only the food energy needed to perform the actual work.
If you want to compare the input and output of small-scale manual farming and farms with animal traction, with fossil fuelled farming, I believe it is quite relevant to not consider the food and feed energy needed for the internal energy, just stick to what comes in and what goes out. This is relevant from a societal perspective as it is about the energy surplus of the agriculture process from the perspective of society.
In a commodity type of farming system where human work is made by people who don't get their food from the farm, you might want to include the food intake of the farm workers as energy.
Good article, not least because it shows how complicated it is to come up with an easy or reliable answer of fossil fuel inputs from farm to plate.
A couple of points:
For many decades the price of food was detached from the price of energy, and some simple economics work I did in the early 1990's suggested that food calorific value was considerably underpriced compared to the oil price at that time. But that all changed when George Bush announced that American crops would be used for ethanol production for vehicles (back when America thought it was running short of oil), and so the price of corn and other suitable crops for ethanol production leapt in price. From then on the corn price has been pegged to the oil price and that has driven up the prices of many other staple crops too.
The other comment is to reverse the equation. If fossil fuel EROEI approaches zero, then food becomes increasingly energy-inefficient, and more and more expensive. So what happens when there is only enough net energy for, say 5 calories of inputs to one of food output? What happens in a war, for example, when diesel is required for the military, leaving food production, processing and delivery short of fuel? Then restricted fuel and other inputs means reduced crop yields, reduced processing, reduced geographical selection (more local produce with less choice), and far more people in food poverty.
The obvious effect is in cities, that are absolutely dependant on just-in-time daily deliveries of huge quantities of food. If we assume, say, half a kilo of food per person per day, then New York's 8 million people need 4 million kilos a day, which is 4000 tonnes, and at an average of say a 5 net tonnes food (plus packaging, pallets etc,) per city delivery truck, 800 trucks a day. Just for the food, excluding drinks, etc.
Three days without deliveries and the supermarket shelves would be empty, and there would be riots.
Very well written. Thank you. One hidden cost in the system is the reduced nutrient density of the crops grown in large scale agriculture operations. Food costs more but feeds your body less.
Yes that is also a very relevant point.
From my records our CSA required around 8 (uh oh) to 37(yikes!) kwh of energy to produce 1 kwh of food energy. Now around half of that was transport to get the food to customers doors but that did not include cooking! Of course farming for money without machinery means using unheated (that's a line I won't cross) greenhouses to produce high value labor intensive crops that tend to be light on calories and the 1000s of kwh in steel and electricity are cheap compared to the cost of 100s of kwh of the farmer's labor. I was still able to produce 1k to 1.5k food calories per hour spent working so if manual labor is around 350 calories an hour endeavor I wouldn't starve though I would need to account for the fact that you often have to spent more time in the kitchen then in the garden. Of course if it really came to it I would probably just irrigate an acre of sweet potatoes which only need some water and a deer fence and my calorie output ratio would skyrocket! That really is the problem with just looking at ratios though or maybe a farming under capitalism as a management exercise problem. Last year I was able to collect 21,000 calories of acorns to make flour for zero energy cost! (well I suppose except for the cost of remembering to bring a backpack on my walk) but a farm gate energy return of infinity doesn't really make sense either.
There is a reason for why vegetables were never a big share of food in almost any culture, especially not leafy vegs, tomatoes, cucumbers and peppers....Thanks for the figures!
"unheated (that's a line I won't cross) greenhouses"
I agree that heating a 3,600 sqft poly tunnel — even with two layers and a full-time fan separating them — is wasteful.
What we did in the winter was the "greenhouse in a greenhouse" technique. We put poly over some of our tables and added a small amount of electric heat.
One year, we had planted our Physalis late, and it hadn't borne fruit by first frost. We piled up greenhouse tables, put all the potted goldenberries in there, put a single, 60 watt incandescent bulb in the centre, and tightly covered the whole thing in plastic.
When we opened it in the spring, a few of the plants in the corners had frozen and died, but most of the plants were healthy — and the ground and greenhouse tables were littered with ripe goldenberries!
Interesting story Jan.
There are a lot of things one can do with a bit of tinkering. I have a small nursery with dubbel plastic (1.5 m2) inside a polytunnel, where I have electric floor heating for my chili and tomatoes when they are too big to keep inside and it is still to cold in the tunnel.
I found a bunch of baseboard heaters for free on CraigsList. I stripped the heating element out of them, put them under my greenhouse tables, covered them with (unfortunately) pink foam insulation, and plugged them into 120 VAC, which reduced their power by 75%. I then covered the tops of those tables with plastic.
Using this technique, I could start seeds in the high teens (°C) without the horribly expensive heating mats designed for the purpose.
I think I'm probably a little bit warmer in the winter, I can't start seeds, but a woven frost blanket to form a mini tunnel within a single layer poly tunnel will usually get the brassicas through the winter.
All of this just indicates we are in a collision course with reality. I have prepared well for our own fuel, our electricity wood for heat and food for us and animals. I started preparing about 50 years ago.Most of our energy comes from human work and the only flaw is my age at 76 years old but still working on the farm. Quite simple really.
I question your "double counting" of human energy, which I have seen you use in your other writings. It takes energy to access energy, whether it is using a diesel-fueled machine to dig coal out of the ground or growing potatoes by digging a trench with a shovel. Just because the farmer digging the trench eats his/her own potatoes does not mean you cannot count the energy input. It is a beneficial aspect of using food energy to grow food, but it does NOT mean it is double counting. The work requires energy. It depends on the use of the expended energy - not the work produced, but the energy actually used for that activity. You do not seem to be including the human labor as embedded energy either, so I don't see how you can conclude it is double counting. Nor are you using Odum's argument that human energy is somehow not the same "quality" as fossil fuel energy, which is just flat wrong. Heat is heat, as Clement and Carnot discovered 200 years ago.
As you know from my first book, I used 125 kcal/hour for input kilocalories for an overall estimate of 3000 hours per year. This includes sitting at the computer working on the farm spreadsheets, writing in the daily journal, driving to market, and sitting at the farm stand while waiting for customers, not just actual physical labor in the field. This is based on 2500 kcal/day in food fuel consumed, with 500 accounted for in 8 hours sleep. This leaves 2000 kcal for 16 hours in the rest of the day. The 3000 hours/year comes from life experience. I even checked this back when I was a market gardener by wearing my heart rate monitor all day long. The overall calorie usage was 125 kcal/hour. When I lived on a dairy farm in my youth, we easily put in 4000 hours a year per person and the dairy farmers I used to corroborate this number back in the decade of the 2000s agreed with me.
Now I am retired and don't have to think about business plans and marketing and all that. I write down my actual hours for work I do in the garden and use the rate of 200 kcal/hour. Last year I put in 598 hours and produced 3002 pounds of food (1365 kilos), with a calorie value of 855,000 kilocalories, or enough to feed .934 people. I don't even count all I harvested, as some crops are just too much trouble, are survival crops like sunchokes, or are only in small amounts or used to feed the birds, like strawberries and sunflowers. These are all rigorous numbers by the way, as I have been anal about numbers and data collection since I was a child.
The point here is that I calculate my inputs and outputs using standardized methods and assumptions. It is I who am doing the work and it takes energy to do so. It makes little difference if the fuel I use to do the work comes from the farm or the store. It takes energy to get energy. The key to an agricultural system is how efficient the energy use is. I note how one of the other commenters (bluejay) has figured out that their CSA program is in negative EROI territory. Mine wasn't, but most sustainable farmers in Whatcom County, Washington, where I used to live and work, were. This was because of their use of tractors, greenhouses, and driving to large urban markets. The upshot is that 25 miles from the farm is the tipping point for a market, even when you have a fuel-efficient vehicle and work yourself to a frazzle. (A person can get a lot done on just a bowl of potatoes or rice in a day. Plantation overseers knew this.)
I would like to know how you came to the conclusion that manual labor is double counting, even with your codicil of "in some cases." Thanks in advance.
Walter, I don't think it is right or wrong here, only different perspectives and purposes, which I also tried to explain, perhaps unsuccessfully.
I appreciate your meticulous recordn keeping and math!
If you want to determine if it makes energetic sense to farm at all, even for someone oriented to self-sufficiency (as opposed to foraging perhaps), the energy return on human labour is of course highly relevant. But then I believe you include all the food needed for fulltime workers and not only the food energy needed to perform the actual work.
If you want to compare the input and output of small-scale manual farming and farms with animal traction, with fossil fuelled farming, I believe it is quite relevant to not consider the food and feed energy needed for the internal energy, just stick to what comes in and what goes out. This is relevant from a societal perspective as it is about the energy surplus of the agriculture process from the perspective of society.
In a commodity type of farming system where human work is made by people who don't get their food from the farm, you might want to include the food intake of the farm workers as energy.
Good article, not least because it shows how complicated it is to come up with an easy or reliable answer of fossil fuel inputs from farm to plate.
A couple of points:
For many decades the price of food was detached from the price of energy, and some simple economics work I did in the early 1990's suggested that food calorific value was considerably underpriced compared to the oil price at that time. But that all changed when George Bush announced that American crops would be used for ethanol production for vehicles (back when America thought it was running short of oil), and so the price of corn and other suitable crops for ethanol production leapt in price. From then on the corn price has been pegged to the oil price and that has driven up the prices of many other staple crops too.
The other comment is to reverse the equation. If fossil fuel EROEI approaches zero, then food becomes increasingly energy-inefficient, and more and more expensive. So what happens when there is only enough net energy for, say 5 calories of inputs to one of food output? What happens in a war, for example, when diesel is required for the military, leaving food production, processing and delivery short of fuel? Then restricted fuel and other inputs means reduced crop yields, reduced processing, reduced geographical selection (more local produce with less choice), and far more people in food poverty.
The obvious effect is in cities, that are absolutely dependant on just-in-time daily deliveries of huge quantities of food. If we assume, say, half a kilo of food per person per day, then New York's 8 million people need 4 million kilos a day, which is 4000 tonnes, and at an average of say a 5 net tonnes food (plus packaging, pallets etc,) per city delivery truck, 800 trucks a day. Just for the food, excluding drinks, etc.
Three days without deliveries and the supermarket shelves would be empty, and there would be riots.
Але зрештою, на місцевому рівні все ще існуватимуть паннаж та гуси на бур'яневому “газоні“ :)