JULES N. PRETTY
is the way to feed the world
Food production will have to increase substantially over the next quarter to half century. That is widely accepted - but views on how to proceed vary hugely.
There are 'environmental pessimists', who suggest that ecological limits to growth are being approached - or have even been passed. For them populations are too great; the growth in crop yield has slowed and will decelerate further; no new technological breakthroughs are likely; and environments have been thoroughly degraded.
By contrast, there are 'business-as-usual optimists', who say that supply will always meet increasing demand, allowing recent growth in aggregate food production to continue alongside reductions in population growth. For them, innovations in biotechnology, combined with the inevitable need to take more land under cultivation, will keep food production rising.
Meanwhile the 'industrialized-world-to-the-rescue' lobby believes that developing countries will never be able to feed themselves, and that the food gap will thus have to be filled by modernized agriculture in the United States and Europe. Increasing production in large, mechanized operations will allow small farmers to go out of business, they say, taking the pressure off natural resources, which can then be conserved in protected areas and wildernesses.
Then there are two groups who both believe that biological yield increases are possible on current agricultural land but are fundamentally divided over the most appropriate approach.
One, which we might call the 'new modernists', argues that growth in food production can only come from high-external-input farming, either in areas that have already benefited from the Green Revolution, or on high-potential land that has been missed by the past 30 years of agricultural development. This group argues that farmers currently use too few fertilizers and pesticides, which are said to be the only way to improve yields and so keep the pressure off natural habitats.
The other group makes the case for the benefits of 'sustainable intensification', saying that substantial growth is possible in presently unimproved or degraded areas while natural resources are protected, or even regenerated. It argues that low-input (but not necessarily zero-input) agriculture can be highly productive, provided farmers participate fully in all stages of technology development and extension. It believes that agricultural productivity is as much a function of human capacity and ingenuity as of biological and physical processes.
This debate poses a key choice for many countries, and is still highly polarized. Many still argue that low external-input agriculture is always low output, that fertilizers and pesticides are the only way to feed the world, that pesticides pose minimal health and environmental risks, and that chemical inputs protect world food security.
Better resource use
The basic challenge for sustainable agriculture is to make better use of available physical and human resources. This can be done by minimizing the use of external inputs or by regenerating locally available resources more effectively - or by combinations of both of these approaches. It ensures efficient use of what is available - and that any changes will persist, as dependence on external systems is kept to a reasonable minimum. Sustainable agriculture seeks to integrate a wide range of pest, nutrient, agroforestry, soil and water management technologies. By-products or wastes from one component or enterprise become inputs to another and - as external inputs are increasingly replaced by natural processes - the impact on the environment is reduced.
Precise and absolute definitions of sustainability, and therefore of sustainable agriculture, are impossible. The approach should be flexible, and not prescribe a concretely defined set of technologies, practices or policies which would only serve to restrict the future options of farmers. As conditions and knowledge change, farmers and communities must be able and allowed to change too. Sustainable agriculture is, therefore, a process of learning, not the imposition of a simple model or package. It does not represent a return to some form of low-technology, 'backward' or 'traditional' agricultural practice. Instead it implies incorporating recent innovations that may originate with scientists, farmers, or both.
At the International Institute for Environment and Development, we have recently examined the extent and impact of sustainable agriculture in a number of countries, and used this empirical evidence to assess sustainable agriculture's potential contribution to food production. We have assessed the transition to sustainable agriculture both from modern, or conventional, high external-input practices and from traditional agriculture where cereal yields have largely remained constant for centuries. As these transitions are recent (within the past five to ten years), they provide evidence that similar improvements could occur on a larger scale.
We estimate that there are some 1.82 million households farming 4.1 million hectares with sustainable agriculture technologies and practices in the 20 developing countries we surveyed. The 63 agricultural projects and initiatives we examined in these countries have important common elements.
- All achievements have occurred within the last ten years (most in the past two to five years).
- All have made use of resource-conserving technologies in conjunction with group or collective approaches to agricultural improvement.
- All have put participatory approaches and community-based activities at the centre of the initiative - so we can be confident that the changes are occurring on local peoples' terms, and so are likely to persist after the projects end.
- None has used subsidies or food-for-work to 'buy' the participation of local people, or to encourage them to adopt particular technologies - so we can be confident that improvements will not disappear at the end of the projects or programmes.
Agricultural productivity per hectare has increased - sometimes substantially - in all the developing country projects assessed. As the survey shows the greatest increases following a transition to sustainable agriculture are in rainfed agriculture in the lowest yield countries, where the average new yields for wheat, maize and sorghum/millet are of the order of double those of conventional or pre-sustainable agriculture.
Smaller increases have occurred in the irrigated lands of Southeast and South Asia (sites of the 'successes' of the Green Revolution), where productivity is already at least three- to five-fold greater than on rainfed lands. Here sustainable agriculture rice yields are slightly more than 10 per cent greater than in modern or pre-sustainable agriculture.
In countries of the Organisation for Economic Cooperation and Development (OECD), a shift to sustainable agriculture is expected to bring a slight short-term decline in productivity - of the order of 5 to 15 per cent - as production levels are so much higher than in Africa, Asia and Latin America. But the decline in the cost of inputs is sharper, and so these systems are more profitable to farmers than modern ones that are fully dependent on high use of external inputs. Evidence suggests that in the longer term (five to ten years) yields in sustainable agriculture will recover to former levels as farmers become more skilled and able to manage their new production systems. In the United States, for example, the top 25 per cent of sustainable agriculture farmers now have better gross margins and better yields than the top 25 per cent of their conventional counterparts.
Widespread adoption of sustainable agriculture would have a significant redistributive effect on productive capacity. Countries which at present produce only low and medium yields - the poorest - will benefit more in terms of increased food production than those that already enjoy high yields.
By 2020, sustainable agriculture would increase global cereal production from 1,950 million tonnes to 2,583 million tonnes, a rise of 32 per cent. The greatest aggregate increase, 502 million tonnes, would occur in medium-yield countries, followed by 106 million tonnes in low-yield nations, and 26 million tonnes in high-yield ones.
Increases in the harvests of staple foods are one beneficial change resulting from sustainable agriculture. There are also improvements to the local economy. There are more jobs: higher wage and labour rates are generally reported from regions practising sustainable agriculture than from neighbouring areas practising conventional agriculture. There is less risk in bad years: stability of output is often more important than the capacity to produce more in a good year. There are steep declines in the use of inputs, and therefore of costs to local farmers. And there are more trees (and more of their products, such as fuel, food, fodder and medicines) and other positive changes in the availability of natural resources, such as increased groundwater in wells and decreased flooding, following the adoption of conservation practices.
Replenishing natural capital
Most agriculture now progressively depletes natural and human capital, by removing soil nutrients, organic matter and water, and by diminishing people's capacity and skills. Current levels of agricultural productivity are thus maintained by asset stripping and underinvestment. But sustainable agriculture helps to form natural capital. It replenishes the stock of soil nutrients, underground water, predators and other beneficial wildlife. So any investment in approaches that help the transition to sustainable agriculture is an investment both in the current and the future capacity to feed the world.
A shift to sustainable agriculture will require a huge investment in building local capacity; in institutionalizing participatory approaches in both governmental and non-governmental organizations; in deepening and broadening research; and in developing appropriate funding mechanisms for community-led activities.
These will all require appropriate incentives to encourage widespread shifts in behaviour and attitudes. The first step is to recognize the benefits that sustainable agriculture can bring, and to enshrine these objectives and processes in new national policies.
Jules N. Pretty is Director of the Sustainable Agriculture Programme at the International Institute for Environment and Development. His book, Regenerating Agriculture: Policies and Practice for Sustainability and Self-Reliance, is published by Earthscan Publications Ltd; James Henry Press; and Vikas Publishers, (1995).