Can permaculture feed the world? ... Well I would say ‘yes’ to that, wouldn’t I?
But whether I’m right or wrong, one thing’s certain: conventional agriculture certainly can’t feed the world for much longer. It’s based on a one-way flow of non-renewable resources and it falls down both on the input side and the output side.
The output includes soil degradation. In the USA, one of the world’s major food exporters, a third of the topsoil that was there when Europeans arrived has been eroded away, and the loss continues at 17 times the rate of soil formation. Carrying on with present farming methods means trying to feed ever more people on an ever-shrinking amount of fertile soil. It can’t be done.
On the input side, perhaps the most significant flow of non-renewables goes into chemical fertilisers. One of the big three nutrients supplied is phosphorous. Phosphorus is mined from deposits of phosphate rock in certain parts of the world and, just like oil, it’s approaching its peak: quite soon world production will be unable to keep up with demand. Nitrogen is required in even greater amounts than phosphorous and it’s extracted from the air by a process which uses a huge amount of fossil fuel energy. As energy prices have risen during the past decade, farmers have seen fertiliser prices more than double. This is just the beginning.
Organic farmers tackle these problems by crop rotation, which here in Britain usually means alternating a few years of cereals with a few years of mixed grass and clover, which is grazed by cattle and sheep. This reduces erosion, though it doesn’t do away with it, and nitrogen is provided by the clover, which ‘fixes’ it from the atmosphere. The downside is that organic farmers only grow cereals on part of the farm at any one time. The temporary grassland does produce human food in the form of meat and milk but this amounts to much less food per hectare than the cereals. This, more than the lower yield of organic cereals per se, reduces the yield of organic farms compared to conventional ones which don’t practise rotation.
Permaculture goes a step beyond this by growing a mix of clover and cereals in the same field at the same time. This is known as bicropping. It enables a cereal, or some other crop for direct human consumption, to be grown every year. The yield of cereal is potentially little lower than it would be if the clover wasn’t there and there’s a modest yield of clover as animal feed.
The clover is present as a permanent understorey, so there’s never any bare soil and thus erosion is eliminated. The permanent ground cover and lack of ploughing also makes ideal habitat for certain fungi, which, in a symbiotic trade-off for organic food, provide the crop plants with phosphorous. Meanwhile the clover provides the nitrogen right where and when it’s needed. There are also positive effects on weeds, pests, diseases and fuel use.1
One factor which helps the bicrop work is the difference in growth pattern of the two plants. The tall cereal and low clover make two distinct levels of vegetation and this reduces competition between the two. We call this stacking.
The most striking form of stacking is agroforestry, in which tree crops are mixed with herbaceous crops, which can include cereals, vegetables or grassland. A traditional orchard of apple trees and pasture is an example. The difference in height between the two elements means that there’s minimal competition between them. In fact when the trees are still young there’s no loss of yield in the herbaceous layer at all.
The annual cycles of the two components are also different. Take for example the combination of wheat and walnuts. The wheat is sown in the autumn and makes much of its growth then and again in the spring before the walnut trees come into leaf. At the other end of the season the walnuts stay in leaf a good two months after the wheat has turned from green to gold. It’s those green leaves which produce food and they’re present for much more of the year in the mixture than they are where either crop is grown alone.
Bicropping and agroforestry are just two examples of how plants can be combined. There are many others and, as long as the combination is well designed, the total yield can be greater than growing each component on its own. This means more food can be grown on less land. The number of components can vary from two to the several hundred which can be found in a diverse forest garden. Mixtures like these are called polycultures, as opposed to monocultures where just one crop is grown.
The Reedbed & The Downland – A Parable
Of all the ecosystems which can grow here in the temperate world none produces more living material per square metre per year than a reedbed. Reeds, having solved the problem of how to grow in a waterlogged soil, have an abundance of resources at their command. They grow in shallow, standing water and thus never want for moisture throughout the growing season. Plant nutrients are washed out of the wider landscape and come to rest in these low-lying places, so the reeds enjoy a supply of nutrients unmatched elsewhere in the natural world. They outgrow and suppress all other plants, so reedbeds are natural monocultures.
Chalk and limestone downland, by contrast, is very well drained. Any short spell without rain means moisture stress. The soil is naturally thin and its supply of nutrients has been further depleted over the generations by historical grazing patterns. Under these conditions no single plant can grow so vigorously as to dominate the others and the level of diversity is phenomenal. Productivity is maintained by each plant doing something slightly different: tall or short, deep rooted or shallow, early-growing or late, nitrogen-fixer and so on. In this way they make more complete use of the modest resources available than a less diverse ecosystem could.
In the fossil fuel age we’ve been able to farm like the reedbed.
We’ve created a series of monocultures with abnormally high levels of nutrients and other resources. In future this won’t be possible and our path to productivity will be to take the model of the downland, which makes maximum use of the limited resources available by means of diversity.
Diversity is much easier to achieve on a small scale than a large one. You can have a much more intimate and diverse polyculture in a home garden than you ever can on a thousand hectare farm. Many of the principles of permaculture – and I’ve only mentioned a few of them here – are much more applicable at a small scale than a larger one. And producing food at a smaller scale will actually help us to feed the world.
We’re often told that European and North American agriculture, with its large, mechanised farms, is the most productive on Earth. It is, but only in terms of productivity per person employed on the land. In terms of productivity per hectare various studies have shown that, broadly speaking, the smaller the farm the more productive it is.2
On a small farm, and even more so in a garden, much more attention can be given to detail and this on its own raises yields. Intricate polycultures, which would be impossible in wide open fields where you get on your tractor in the morning and drive like hell all day, become much more feasible when your unit of production is not the hectare but the individual plant.
One of the great thrusts of permaculture is to empower more people to grow more of their own food right where they live. A permaculture vision of the future would include a lot more people growing their own fruit and vegetables, whether in city, town or village. Dry foods such as grains, and animal products, would still come from the countryside, but the size of the farms producing them would be somewhat smaller than now.
This will mean a lot more people growing food. As the price of food inexorably rises, which it certainly will as population rises and fossil fuels become less abundant, I have little doubt that food production, whether for home consumption or for a living, will become more and more attractive and lose the lowly image it now has.
All the above represents a complete change of direction in both agriculture and society, away from the current trends towards monoculture and urbanisation.
I don’t claim that permaculture has all the answers but I do see this change of direction as an essential component in a sustainable future. But in itself it’s only half of permaculture.
The other half is permaculture as a design system. Although it’s less specifically directed towards raising yields, permaculture design can make anything run more efficiently and harmoniously. So it too has a part to play in feeding the world. But perhaps it’s a subject for another time.
Patrick Whitefield (1949-2015) was a permaculture teacher and author. He wrote the first books about permaculture for temperate Europe including the acclaimed The Earth Care Manual – A Permaculture Handbook for Britain and Other Temperate Climates, How To Make a Forest Garden, and How To Read the Landscape and was consulting editor at Permaculture magazine from 1992 - 2015.
1 For more information on bicropping see The Earth Care Manual, pp268-275.
2 See The Earth Care Manual, p31.