Prof. Jules Pretty 

Research Interests

Sustainable and Ecological Agriculture

Despite several decades of remarkable agricultural progress, the world still faces a massive food security challenge, with an estimated 790 million people lacking adequate access to food. Most agree that food production will have to increase in the coming years, and that this will have to come from existing farmland. But solving the persistent hunger problem is not simply a matter of developing new agricultural technologies. Most hungry consumers are poor, and so simply do not have the money to buy the food they need. Equally, poor producers cannot afford expensive technologies. They will have to find solutions largely based on locally-available natural, social and human resources. The key questions are, therefore, to what extent can agricultural systems become more productive whilst not causing harm to the environment, and do these offer any new hope for the hungry?

Something is wrong with our agricultural and food systems. Despite great progress in increasing productivity in the last century, hundreds of millions of people remain hungry and malnourished. Further hundreds of millions eat too much, or the wrong sorts of food, and it is making them ill. The health of the environment suffers too, as costly degradation seems to accompany many of the agricultural systems we have evolved in recent years. Can nothing be done, or is it time for the expansion of another sort of agriculture, founded more on ecological principles, and in harmony with people, their societies and cultures?

In the earliest surviving texts on European farming, agriculture was interpreted as two connected things, agri and cultura, and food seen as a vital part of the cultures and communities that produced it. Today, however, our experience with industrial farming dominates, with food now seen simply as a commodity, and farming often organised along factory lines. To what extent can we put the culture back into agri-culture without compromising the need to produce enough food? And can we create sustainable systems of farming that are efficient and fair and founded on a detailed understanding of the benefits of agroecology and people’s capacity to cooperate?

As we advance into the early years of the 21st century, we have some critical choices. Humans have been farming for some 600 generations, and for most of that time the production and consumption of food has been intimately connected to cultural and social systems. Foods have a special significance and meaning, as do the fields, grasslands, forests, rivers and seas. Yet over just the last two or three generations, we have developed hugely successful agricultural systems based on industrial principles. They certainly produce more food per hectare and per worker than ever before, but only look so efficient if we ignore the harmful side-effects – the loss of soils, the damage to biodiversity, the pollution of water, the harm to human health.

Over these 12,000 years of agriculture, there have been long periods of stability, punctuated by short bursts of rapid change. These resulted in fundamental shifts in the way people thought and acted. We are at another such junction. A sustainable agriculture making the best of nature and people’s knowledges and collective capacities has been showing increasingly good promise. But it has been a quiet revolution because many accord it little credence. It is also silent because those in the vanguard are often the poorest and marginalized, whose voices are rarely heard in the grand scheme of things. No one can exactly say where this revolution could lead us. Neither do we know whether sustainable models of production would be appropriate for all farmers worldwide. But what the principles do apply widely. Once these come to be accepted, then it will be the ingenuity of local people that shapes these new methods of producing food to their own particular circumstances.

We know that most transitions involve trade-offs. A gain in one area is accompanied by a loss elsewhere. A road built to increase access to markets helps remote communities, but also allows illegal loggers to remove valuable trees more easily. A farm that eschews the use of pesticides benefits biodiversity, but may produce less food. New agroecological methods may mean more labour is required, putting an additional burden on women. But these trade-offs need not always be serious. If we listen carefully, and observe the improvements already being made by communities across the world, we find that it is possible to produce more food whilst protecting and improving nature. It is possible to have diversity in both human and natural systems without undermining economic efficiency.

In recent research, we examined the extent to which farmers have improved food production in recent years with low-cost, locally-available and environmentally-sensitive practices and technologies. We analysed by survey during 1999-2000 208 projects in 52 developing countries, in which 8.98 million farmers have adopted these practices and technologies on 28.92 million hectares, representing 3.0% of the 960 million hectares of arable and permanent crops in Africa, Asia and Latin America.

We found improvements in food production occurring through one or more of four mechanisms: i) intensification of a single component of farm system; ii) addition of a new productive element to a farm system; iii) better use of water and land, so increasing cropping intensity); iv) improvements in per hectare yields of staples through introduction of new regenerative elements into farm systems and new locally-appropriate crop varieties and animal breeds. The 89 projects with reliable yield data show an average per project increase in per hectare food production of 93% (see Figure 1).

There are several key practices and technologies that have led to these increases: increased water use efficiency, improvements to soil health and fertility, pest control using biodiversity services with minimal or zero-pesticide use, and social organization for collective action. This research reveals promising advances in the adoption of practices and technologies that are likely to be more sustainable, with substantial benefits for the rural poor. With explicit support through national policy reforms, better markets, and more integrated and cross-disciplinary approaches to science, these improvements in food security could spread to much larger numbers of farmers and rural people in the coming decades.

Social learning is a vital part of the process of adjustment in sustainable agriculture projects. The conventional model of understanding technology adoption as a simple matter of diffusion, as if by osmosis, no longer holds. But the alternative is neither simple nor mechanistic. It involves building the capacity of farmers and their communities to learn about the complex ecological and biophysical complexity in their fields and farms, and then to act in different ways. The process of learning, if it is socially-embedded, provokes wider changes in behaviour.

Farmers require timely information on pest-predator relationships, moisture and plants, soil health, and the chemical and physical relationships between plants and animals. These are subject to manipulation – and farmers who understand this, and who are confident about experimentation, are better innovators. The empirical evidence tells us two important things. Social learning leads to greater innovation together with increased likelihood that social processes producing these technologies are likely to persist.

Several things are now clear with respect to sustainable agriculture:
i. The technologies and social processes for local level agro-ecological improvements are well-tested and established;
ii. The social and institutional conditions for spread are less well-known, but have been established in several contexts (in particular social groups at local level and novel partnerships between external agencies;
iii. The political conditions for the emergence of supportive policies are the least established, with only a very few examples of real progress.

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