Garden Variety

Crop improvement, environmental sustainability and higher farm incomes all depend on agricultural biodiversity - as does simply consuming a healthy, balanced diet.

Agricultural biodiversity is well understood to be a source of desirable traits. The genetic bases of disease resistance, for example, are sought in the vast array of agricultural biodiversity and then bred into existing crop cultivars and livestock breeds to create new cultivars and breeds that are better able to thrive under stress. This kind of scientific breeding will remain important as the world grapples with feeding more people a better diet using fewer resources. However, agricultural biodiversity can also deliver better nutrition, enhanced resilience, greater sustainability, and higher farm incomes, all of which offer pathways out of poverty.

Nutrition is perhaps the most important. More than 60 years after the start of the Green Revolution, hunger still stalks more than a billion people, and 2 billion people, mostly young women and children, suffer the "hidden hunger" of micronutrient deficiency.

The problem is not simply the lack of proteins or calories, but the lack of diversity in the diet, which is one way to guarantee of an adequate supply of micronutrients. Very good evidence from several studies, mostly in the developed world but increasingly from developing countries, indicates that a diverse diet protects people from several non-communicable diseases and is associated with a longer, healthier, more productive life.

Non-communicable diseases such as obesity, type 2 diabetes, heart disease and cancer were long thought of as diseases of affluence, but they are spreading most quickly in low- and middle-income countries, where 80% of the deaths from them occur. Current approaches to the problems of malnutrition are clearly not working. Agricultural biodiversity as the basis of healthy diets and resilient food systems offers a fresh approach.

In Kenya, people traditionally ate more than 200 species of leafy vegetables. Almost all are much more nutritious than the cabbage and kale that were often the only green vegetables for sale in cities, but their wider use is stymied by perceptions of backwardness, supplies that are erratic and unhygienic, and the ignorance of younger adults, especially in cities, about how to prepare them.

Working with a range of partners, Bioversity International trained Kenyan farmers to grow traditional leafy vegetables and worked on quality control and supply chains. Supermarkets were enlisted to help make the produce available in cities, and colorful leaflets offered recipes for preparing them. Well-known entertainers and government figures endorsed traditional foods on mass media. The result was an increase in deliveries to markets from 30 tons per month to 400 tons per month 3 years later. The retail value of the trade is estimated to be US$1.5 million weekly, and the incomes of farm families supplying the vegetables have increased by a factor of 2 to 20.

Although the vegetable species and some intervention techniques are specific to East Africa, the general methods and ideas behind this initiative are applicable globally. Similar projects promoting Andean grains in Bolivia and Peru, nutritious millets in India and Nepal, and nutrient-rich fruits in the Pacific are making considerable headway.

When the World Health Organization (WHO) and others first sounded the alarm about micronutrient deficiency, they said that dietary diversity was the preferred option for tackling the problem. This original emphasis was slowly overtaken by a much more clinical approach, which saw each deficiency as a distinct disease to be cured by administering a specific supplement. Supplements, fortified foods and biofortified staples currently rule, but the original food-based solutions advocated by WHO and others need to be reassessed. The CGIAR's proposed Mega Program on Agriculture for Improved Health and Nutrition will go a long way toward reasserting the primacy of food-based approaches, including biofortification where appropriate, and will help policymakers understand that there are alternative ways to tackle malnutrition that often provide other benefits as well.

Ecosystem complexity is known to go hand in hand with resilience, and this applies to agricultural ecosystems. Growing different varieties of crop species can control pest and disease outbreaks, augmenting farm profitability, and also allows the best use of diverse growing conditions. Access to a range of cultivars gives farmers more options for dealing with capricious weather, as a variety that avoids drought or flood by maturing quickly can mean the difference between life and death. Livestock and fish add to human nutrition and can also contribute to soil fertility and farm incomes. Additionally, agricultural biodiversity will be essential for adapting agriculture to climate change.

The multiple benefits of making greater use of agricultural biodiversity in these various ways will be seen in long-term improvements that will be self-sustaining, as healthier communities engage in a diversified and less destructive agriculture that offers a nutritionally superior diet, which in turn keeps communities healthier - all with profound effects on economic development.