Nearly 50% of the world labour force is employed in agriculture. Distribution in the late 1980's ranged from 64% of the economically active in Africa to less than 4% in America and Canada. In Asia the figure was 61%; South America, 24%; Eastern Europe and Russia 15%; Western Europe 7%.
Many people believe that agriculture in this country (and in the other industrialised countries) is getting more and more efficient. They perhaps get this impression on account of the fact that yields of crops are going up all the time. They may also be influenced in their thinking by the fact that farming is getting increasingly mechanised and requires less and less labour. Nowadays one person can farm hundreds of acres of arable land, whereas fifty years ago they might only be able to farm twenty acres.
But these facts do not in any way indicate greater efficiency. What they do show is an increase in productivity, which is a very different thing. Productivity means the amount produced per unit area of land or per person employed. There is no doubt that both these indices of agricultural production have increased enormously in the last half century. But efficiency has actually gone down over the same period.
This apparent paradox arises because of a misunderstanding about the meaning of the word efficiency. It has nothing to do with productivity. The efficiency of a system means the ratio between the work or energy got out of it and the work or energy put into it. The more energy we get out per unit amount we put in, the more efficient the system is. Theoretically the maximum efficiency is when the energy put in is equal to the energy got out - such a system has an efficiency of 1 (or 100%). But in practice it is impossible to have an efficiency as high as 1, because that would mean a perfect mechanism which had no energy losses at all.
In agricultural systems the energy inputs are of two kinds. On the one hand there is the sun's energy, which is absolutely necessary for plant growth and which is virtually inexhaustible, freely available and generally beyond our control. On the other hand there is all the rest of the energy used, usually referred to as the support energy, which is under our control, has a cost and is exhaustible.
This support energy consists of such things as the energy used by people and draught animals in their work, the energy used to manufacture farming tools and machinery, the fossil fuels used to power the machinery, the energy used by the chemical industry to produce the fertilisers, pesticides, herbicides, plastics, etc., the energy used in food processing and the fuel used to transport the produce to the consumer.
Not all of these energy inputs are taken into consideration in comparing the efficiency of different food production systems. The sun's energy is usually left out of the calculations because it is assumed that, in a given place, it is constant, whatever the farming methods being used. Labour energy is sometimes left out as being negligible, but more often put in as a nominal value equal to the energy used in the worker's muscles. Energy consumed in processing food and transporting it to the consumer is normally left out because it is not considered relevant. Only energy consumed within the boundaries of the farm is put into the calculations.
The merits of the arguments for and against including these inputs in the calculation are discussed later. For now it is convenient to leave out all of them apart from a nominal value for labour and settle on a simplified index of agricultural efficiency called the output/input ratio (see footnote*), which is the ratio of the energy in the crops produced to the energy consumed on the farm to produce them. Most of this input energy is in the form of fossil fuels, which are used either directly to power tractors etc. or indirectly in the manufacture of goods, such as fertilisers and machinery, that are bought in.
Comparative Farming Systems
It is important to realise that output/input ratio is not exactly the same as efficiency. However, for any set of agricultural systems the output/input ratio is proportional to the efficiency, so we can use the ratio to compare the efficiency of one system with another. Here we are going to use it to compare farming in this country years ago with farming today, farming in rich countries with that in poor countries, primitive food production with modern industrialised agriculture, organic with conventional farming and animal rearing with stockless (vegan) farming.
Another value of the output/input ratio is that it is a good measure of the extent to which an agricultural system is using up the earth's resources. It relates the energy put out in the form of crops to the energy put in as fossil fuels, etc. If the former is less than the latter, energy is being lost and so the earth's resources are being used up. In other words, if the output/input ratio is less than one, the system is using up the earth's energy supply and so is not sustainable. A sustainable system must have an output/input ratio equal to or greater than one.
Let us look, as the first example, at how the efficiency of agriculture has changed in this country over the last century and a half. Bayliss-Smith,1982) (l) calculated the output/input ratio for English agriculture in 1826 to be 40.3. In 1971, according to the same author, it had fallen to 2.1 - a twenty-fold decline in efficiency. Uhlin (1997)(2) arrived at a ratio for Swedish agriculture in 1972 that was even worse - 0.76. However, according to his calculations, the ratio had increased to 1.14 by 1993.
For a clarification of the difference between output/input ratios and efficiency, please see the Note about Efficiency at the end of this piece.
These figures indicate that, with the increasing mechanisation and chemicalisation of agriculture, agricultural efficiency in Europe declined steeply up to the nineteen seventies. The decline then bottomed out and the ratio has risen again very slightly since then, which is confirmed by Bonny's (3) study of cereal production in France.
This slight rise, which brings agricultural efficiency back to where it was in the fifties, is probably due to increased industrial efficiency, more efficient machinery and more prudent use of agricultural chemicals. But the overall conclusion is that Western European agriculture is now barely sustainable, even when the enormous energy costs of transport and food processing are not included.
As another example of the use of output/input ratios we can look at a comparison of agriculture in different countries carried out by Conforti and Giampietro (4). They excluded from their calculations all energy inputs other than fossil fuels. In most cases this is a good approximation, because fossil fuels constitute over 90% of total energy inputs. They compared the output/input ratios of 75 countries world-wide and found that the value of the ratio varied from 156 to 0.41.
The countries with the most inefficient agriculture (those with output/input ratios of 2 and below) included most of the rich countries of the world - Western Europe, USA, Israel, Japan, Australia and New Zealand. The countries with the most efficient agriculture on this scale (with ratios from 30 upwards) included Ghana, the Central African Republic, Niger and Uganda**. These results speak for themselves.
Even more eloquent are comparisons of output/input ratios of primitive and industrialised agricultural systems. Steinhart and Steinhart (5) worked out output/input ratios for shifting agriculture (like slash-and-burn) as about 28 and for hunting and gathering as 4. Leach (6) gives 4.5 for hunting and gathering, which compares with his figure of 3.35 for intensive wheat production in the UK.
The same author puts subsistence farming in the range of 11 to 61, as compared with 0.35 (unsustainable!) for UK agriculture as a whole. Potato production in the UK has an output/input ratio of 1.57 and rice in the USA of 1.3 - both barely sustainable. He gives two figures for shifting agriculture in two different countries (New Guinea and Congo) - 20 and 65 respectively. So primitive farming, and even hunting and gathering, is far more efficient than modern industrialised agriculture.
Beef Farming -The Most Inefficient
Particularly interesting are two figures that Leach gives for maize production in Guatemala - one for purely manual work and the other for oxen power. The output/input ratio for the manual cultivation is 14 and the one with oxen is only 4. This shows the efficiency of manual work and calls into question whether animal power is of any advantage. Very little work has been done on the relative efficiency of conventional and organic cultivation. The only relevant published results are those of Kopke and Haas (7), who studied energy use and carbon dioxide emissions on conventional and organic farms in West Germany.
According to them organic farming used only about a third of the energy per unit area of land than conventional farming did. Their work does not deal with outputs, but, even if we make a very conservative estimate and say that on organic farms the yields are only two thirds of what they are on conventional farms, we still find that organic farms are far more efficient than conventional ones - about twice as efficient, in fact.
Finally, we can use output/input ratios to compare the efficiency of animal farming with that of crop production. Here the results are not so clear cut. It very much depends on what kind of animal farming we are talking about. Intensive beef production, as practised in the UK, is probably about the most inefficient form of farming there is, having an output/input ratio of about 0.08 (8). On the other hand, nomadic herding is relatively very efficient. Gomez - Ibanez (9) has done a study of sheep rearing in the western USA and has shown that, with the decline of transhumance*** and the change to more settled forms of grazing, the efficiency drops substantially.
Lies, Damn Lies and Statistics
It must be emphasised that all the figures on efficiency quoted above are in a sense provisional results and should be treated with a certain amount of caution. Agroecology is still not an exact science. Its practitioners have not even agreed yet on the definition of terms or on an appropriate methodology. The disagreement (referred to above) about what to include on the input side is a typical example of this.
Some researchers (especially those who are supporters of modern agriculture) are reluctant to include any inputs beyond the farm gate, believing that they are irrelevant to agriculture. That is why they disregard the energy cost of food transport and processing. But this can lead to very misleading results, because in the industrialised countries those costs represent nearly two thirds of the total energy consumed in food production (10) ; so their inclusion in the calculations can turn what is apparently a sustainable system into one that is completely unsustainable.
Many critics of modern agriculture (e.g. Perelman (11) would argue that a large increase in the processing and transport of produce is inseparable from modern farming methods. in primitive agriculture farmers grew a wide range of crops to satisfy most of the needs of their own community. Consequently a large part of their produce was consumed locally. With the introduction of industrialised methods of farming, involving specialisation in a few crops, it became necessary to process the food and transport it great distances. one region specialising, for example, in cereal production could not satisfy all the food requirements of the local population, so other produce such as vegetables had to be transported in from other regions.
Another broad area of disagreement in agroecology (which has been well reviewed by Fluck and Baird (12) is the energy. value of human labour in farming. Many researchers take it as being equal to the energy consumed by the human body in carrying out the physical work involved, which means that in all systems the labour energy per unit of time worked would be roughly the same. However, this may be an oversimplification, because it leaves out the energy cost of the reproduction of labour and that varies enormously from one society to another. In a primitive society most of the labour energy is consumed in food production and in domestic tasks like home making and bringing up children.
But in an advanced industrial society we must add to that all the energy consumed in support services like health services, social services and education, not to speak of the huge entertainment industry. In fact some researchers have gone as far as to suggest that the energy cost of labour is equal to the total gross national product of a country divided by the number of workers. This would give a figure up to ten times greater than the simple calculation of the energy expended by a person in the work itself. And if we applied this inflated figure for the energy cost of human labour to countries like Ethiopia and Tanzania, their agriculture would probably appear very much less efficient than previously stated.
So the relatively high efficiency of agriculture in poor countries could have something to do with the low energy requirements of their agricultural workers. This point needs more research. But there could be an important lesson for us in all this - that the only way to make food production more efficient and hence sustainable is to simplify our lives and greatly reduce our material standard of living.
Agricultural systems entail costs for society which the farmer usually does not have to take into account. These not only include transfer payments in the form of subsidies which farmers receive, either paid for by the taxpayer or the consumer in the form of higher food prices. They also include the costs of putting right environmental problems caused by farming practices.
The costs of ensuring clean water supplies without excessive levels of nitrates, the costs of monitoring foodstuffs for pesticide residues or cleaning up water courses after accidents at agrochemical plants, the costs of conserving threatened habitats and environmentally threatened areas to name but a few.
The Treadmill of Higher Productivity
Some people, who might otherwise agree with the idea of a simpler life, may feel that the exclusive emphasis in this article on efficiency as the main goal in farming is playing into the hands of our opponents. They may feel that it is precisely the emphasis on efficiency that leads to the dehumanisation of human activities and that turns work into a treadmill. Not so.
This misconception again arises from a confusion between efficiency and productivity. It is the pressure for greater productivity of labour that gives rise to the treadmill. Efficiency in agriculture, as practised in less developed societies, leads to more leisure time and more time for cultural activities in the broadest sense. Hunter gatherers, for example, need to spend only 25% of their waking time to satisfy their whole food needs (13). The rest of the time is available for domestic and social tasks and creative artistic activities.
"The Earth's total resources cannot accommodate the spread of the West's high energy consumption…. of oil and other minerals (which) is out of all proportion to its percentage of the world's population."
Richard Norton Taylor.
It is when we take a very long term view that the paramount importance of agricultural efficiency becomes apparent. The only process in the world that actually adds to the world's net energy and order is photosynthesis, which takes the sun's energy and stores it in plant tissues like wood (14) . Even fossil fuels were originally produced in this way. Nature is highly efficient by our definition and stored a lot more energy than was needed. So a vast reserve of energy was built-up over millennia. it is this reserve that we are now living off. When it is gone, there will only be the current energy of photosynthesis to live off.
Why Vegan Agriculture Is Imperative
In other words, we will have used up all the energy capital that we can and will be back to living off the interest again. In that situation, with no reserves, it will be imperative that essential human activities, such as food production, yield more energy as food than the support energy they use. If not they will quickly use up the world's remaining energy reserves and the result will be starvation.
It would be wrong to suggest, by the way, that energy supply will be the only constraint on agriculture in the future. As the human population of the earth increases, shortage of land may also become a problem. In this case, the reversion to primitive farming, which the energy shortage will necessitate, will not help, because it will result in lower yields of food per unit area of land. The answer lies in the fact that at present a large proportion of agricultural land is given over to animal rearing, which is a very unproductive use of the land. Crop production could yield up to ten times more food than animal rearing. So, in the words of John Ikerd and his co-authors (15), "much of...... our food supply problems could be solved by eating lower on the food chain", or, in other words, by a move towards a vegan diet. However, this opens up a whole new area of debate.
A note about "efficiency" and "output/input ratio"
The efficiency of a system is the ratio of all the work or energy got out of it to all the energy or work put into it. So, for example, if you put 10,000 calories of work into a system, but only get 5000 calories out, the efficiency is 5000/10,000 = 0.5. We get the real efficiency of the system when we include in this calculation all the energy inputs and outputs. But we may not always want to do that. We may want to compare two farming systems but omit some of the inputs. There are two main reasons why we might want to do that. In one case a particular input might be exactly the same for both systems and hence makes no difference to their relative efficiency.
For example, if we are comparing the efficiency of two neighbouring farms, one organic and the other conventional, we can assume that the intensity of solar radiation that they receive is the same. So it is usual to omit solar radiation from the inputs in such cases. Another reason for omitting a particular input is if it is considered to be relatively so small as to be insignificant. Some researchers have omitted the energy of human labour on these grounds (although in another article I have argued that human labour is, in fact, the biggest input of all).
But, if we have omitted some of the energy inputs, we can no longer call the quantity that we calculate the efficiency of the system, so we give it another name - output/input ratio. As long as we consistently omit the same inputs for one of the above reasons, the output/input ratio will be roughly proportional to the efficiency, so we can use it to compare the efficiencies of different farming systems.
However, there is one noticeable difference between the figures for efficiency and those for output/input ratio. Efficiency is always less than 1, because you can never get more energy out of a system than you put in. In an ideal system there would be no wastage at all, so all the energy put in is converted into useful work or energy. In this case the output would exactly equal the input, so the efficiency would be 1, but this can never be achieved in practice.
However, as I have explained above, it is customary to omit from the calculation some of the inputs, like solar energy or human labour, so in that case it is quite possible to have a total output that exceeds the total input. In that case the calculated output/input ratio would exceed 1. That is why the figures that I have used to compare different farming systems are greater than 1.
For example, I pointed out that primitive agriculture can have an output/input ratio as high as 60, whereas that of modern agriculture is generally between 1 and 2. If we compare all systems of agriculture in this way, we have to conclude that no-dig vegan-organic cultivation using solely manual methods or intermediate technology is the most efficient food production system there can be.
* To confuse things some authors use the input/output ratio, which is just the reciprocal of the output/input ratio.
** This result may seem incredible to many people, for whom the names of the sub-Sahelian countries of Africa are associated with hunger and, at times, starvation. The point is, it is not inefficient agriculture that leads to starvation - it is caused principally by wars, acts of genocide and foreign interference in the economy.
*** The practice of alternating the grazing, according to the season, between
two different areas, often very far apart. In the south of Europe this was,
until recently, the normal practice in sheep husbandry. The sheep were grazed in
the mountains in the summer and in the lowlands in the winter and had to walk
sometimes hundreds of kilometres between the two.