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According to conventional wisdom, the Brazilian city of Belo Horizonte (pop. 2.5 million) has achieved something impossible. So, too, has the island of Cuba. They are feeding their hungry populations largely with local, low-input farming methods that enhance the environment rather than degrade it. They have achieved this, moreover, at a time of rising food prices when others have mostly retreated from their own food security goals.
The conventional wisdom contradicted by these examples is that high yielding agricultural systems necessarily reduce biodiversity. Sometimes this assumption is extended to become the 'Borlaug hypothesis' after Norman Borlaug, the architect of the green revolution. The Borlaug hypothesis states that the preservation of rainforests, an example of biodiversity, depends on intensive industrial production of sufficient food to allow for the luxury of unfarmed areas (e.g. Trewavas, 1999).
So, since Belo Horizonte and Cuba appear to have defied this logic, what is their secret? Are they succeeding in spite of their commitment to sustainability, or because of it? Or is conventional wisdom simply wrong? These pressing questions are explored in a new review, Food security and biodiversity: can we have both? by Michael Jahi Chappell and Liliana Lavalle, and published in the journal Agriculture and Human Values.
A pathbreaking new approach
Whether agricultural productivity and biodiversity are mutually exclusive has only recently emerged as a central question in agriculture. It follows increasing awareness, both that global biodiversity is in rapid decline, and that much of the decline is a result of industrialised agriculture. This is evident from data as diverse as increases in the number and size of ocean dead zones to declines in pollinators (Cameron et al 2011).
However, as the number of those who go hungry swells, countries and development advocates see themselves as faced with seemingly impossible choices between food security and environmental degradation. Such pressures, together with the acknowledgment that the productivity of industrialised agriculture can be short-lived, have stimulated academics and others to reexamine their thinking (e.g. Tscharntke et al 2011).
Perhaps the best-known attempt to rigorously evaluate the biodiversity versus food question was the International Assessment of Agricultural Knowledge, Science Technology and Development (IAASTD). This United Nations-sponsored commission was set up to resolve the competing ways forward being offered for agriculture. Reporting in 2007, the IAASTD commission left its mark mainly by pointing out that it is a mistake to think of agriculture as simply about productivity. Agriculture provides employment and livelihoods, it underpins food quality, food safety and nutrition, and it allows food choices and cultural diversity. It is also necessary for water quality, broader ecosystem health, and even carbon sequestration. Agriculture, concluded the IAASTD, should never be reduced merely to a question of production. It must necessarily be integrated with the many needs of humans and ecosystems.
According to John Vandermeer of the University of Michigan, the IAASTD report "did conclude that food security and biodiversity could be reconciled". Amidst discussion of many other issues that conclusion, however, was largely lost. What Chappell and LaValle have contributed, he says, is to focus specifically on the question of whether biodiversity and food security can co-exist in the same place. "They have brought together the data that can resolve the contradictions contained in both sides of the biodiversity versus food argument", he says. Helda Morales, Professor of Agroecology at El Colegio de la Frontera Sur, Mexico, agrees. "This is a careful review of the relevant information available on biodiversity and food security."
Sustainable agriculture and productivity
Yields are the first issue Chappell and LaValle considered. Surveying the scientific evidence, they find it supports the idea that a 'hypothetical world alternative agriculture system' could adequately provide for present or even predicted future populations. This is primarily because present and future populations do not need more food than we currently produce. But it is also because agroecological methods involve only a minor yield loss compared with the best that industrial agriculture has to offer. Indeed small farms, which they believe will have to be the basis of any future sustainable agriculture, typically yield more than larger ones. Both conclusions are accepted by Teja Tscharntke, Professor of Agroecology at Georg-August University in Goettingen, Germany. "Hunger in the developing countries can only be reduced by helping smallholders," he says, and even in Germany, "organic farming would easily feed the population if nutritional recommendations were followed".
Sustainable agriculture and biodiversity
On the question of whether agroecological methods also enhance biodiversity, the answers appear even more clear cut. While industrialised agriculture is often considered the biggest single global contributor to extinction, biodiversity of every kind is enhanced on farms that avoid industrial methods compared with farms that do not. A recent meta-analysis cited by the review put this figure at "30% more species and 50% more individuals" on agroecological farms. Chappell and LaValle found that smaller farms using agroecological methods are more biodiverse and less harmful to the environment generally. This finding was consistent over a wide range of localities, crops and production systems. Probably that is because multiple aspects of industrialised agriculture, from large field sizes to the use of nitrogenous fertilisers and pesticides, are each associated with biodiversity losses.
Agriculture is a system that functions within bigger ecological, political and economic systems. Success, therefore, must ultimately be judged at that level. Chappell and LaValle consider that the two examples they studied—Belo Horizonte and Cuba—offer tentative evidence of success at a regional level. Of these two, Cuba's commitment (and also success) appears to have been the greater. It is claimed, for example that the "capital city of Havana is now almost entirely supplied by alternative agriculture, in or on the periphery of, the city itself". They acknowledge, however, that two examples do not prove anything except a principle. As Teja Scharntke puts it "such examples may be models for some but not all countries."
Nevertheless, say Chappell and LaValle, this all points to the conclusion that "the best solution to both food security and biodiversity problems would be widespread conversion to alternative practices." Instead of supporting a competitive relationship "the evidence emphasizes the interdependence of biodiversity and agriculture." Helda Morales goes even further "I would go beyond this statement and say that we cannot have food security if we do not have biodiversity".
For John Vandermeer, the uniquely holistic approach of Chappell and LaValle is the key to a consensus. "When people dispute these conclusions, it is almost invariably because they are using too narrow a frame of reference." And it is a consensus that appears to be gaining wider attention. In December of 2010 The United Nations special rapporteur on the right to food published a document asserting that agroecology had demonstrated "proven results" and that "the scaling up of these experiences is the main challenge today."
The immediate practical obstacle, however, to choosing a food system that supports both food security and the environment is public policy. Citing Per Pinstrup-Andersen, the former Director General of the International Food Policy Research Institute, Chappell and LaValle state: "It is a myth that the eradication of food insecurity is truly treated as a high priority." The real obstacles to ecological high-yield farming, Vandermeer believes, are research priorities and economics. "Industrial farming only appears to be more viable because it is subsidised." Even though there are at present some uncertainties, "If we applied the same research efforts to agroecological approaches that we currently do to support industrialised farming, even more could be achieved."
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- Chappell MJ and LaValle LA (2011) Food security and biodiversity: can we have both? Agriculture and Human Values 28: 3-26. Author Copy
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