The agricultural biodiversity connection to feeding the world - DG Dialogues
Following her speech at the Economist's Feeding the World event earlier this month, Bioversity International Director General, M. Ann Tutwiler, blogs about why we need to diversify our food and agricultural systems to minimize risk.
Following her speech at the Economist's Feeding the World event earlier this month, Bioversity International Director General, M. Ann Tutwiler, blogs about why we need to diversify our food and agricultural systems to minimize risk.
In finance, we know that diversification minimizes risks and leads to greater long term prosperity. In agriculture, however, instead of diversifying, we’ve specialized. We are betting the farm on a few crops — three crops (maize, rice and wheat) that account for over half of our plant based calories. This specialization has enabled tremendous gains in the productivity of these three crops since the middle of the 20th century. These productivity gains were fuelled by plant breeding, chemistry and engineering and, particularly in Asia, helped reduce the share of hungry people from a quarter to an eighth of the world’s population.
At the beginning of the 21st century, we find ourselves facing new challenges. On the production side, staple crop yields are plateauing, weather patterns are becoming unstable and unpredictable, and soil fertility is diminishing, water tables are falling, and water quality is suffering from overuse of mechanical and chemical inputs. On the consumption side, more than 800 million people don’t have enough food to eat, 2 billion people suffer from micronutrient deficiencies and over 1 billion people are obese from diets that rely too heavily on starches and fats. To sustainably meet the nine billion people’s demand for food in 2050, we need a new paradigm based on biology and knowledge: we need to diversify.
Agricultural and tree biodiversity can and must play a central role in shaping this new paradigm. Through greater conservation and maintenance of our agricultural and tree genetic resources, and their sustainable use, we can foster robust, agroecological systems to meet these new challenges.
Many people associate biodiversity with organic agriculture — heirloom tomatoes and purple potatoes — for prosperous consumers. They believe that EITHER we have highly productive, mainstream, conventional, specialized agriculture OR we have biodiverse, low-yielding organic farming. I believe this is a false choice. Instead of Either/Or, we need to think Both/And. Agricultural biodiversity offers a Both/And solution. We need to begin to incorporate the solutions agricultural biodiversity offers into our food and agricultural systems.
Agricultural biodiversity can reduce losses from pests and diseases. For example, 25 per cent of food losses in developing countries are 'pre-harvest' losses due to pests and diseases. Genetic uniformity in crops intensifies the risks of pre-harvest losses. There are famous examples of past blights — Irish potatoes in the 1840s and US corn in the 1970s and more recently, Cavendish bananas — where the reliance on a single variety enabled diseases to run rampant. Simply planting more varieties together can sharply reduce these risks.
In China, rice blast is a serious disease, causing losses of up to 37 per cent. Simply by planting three varieties together in the same field, the damage caused by rice blast is reduced six fold. In Uganda, common beans face losses of up to 25%. Again, planting five to ten different varieties of beans together substantially cuts the losses from diseases — without the use of chemical pesticides.
Agricultural biodiversity can enhance resilience. Following Hurricane Ike, in Cuba monoculture farms lost 90 to 100% of their crops; neighbouring diversified farms suffered losses of 'only' 50%. These agroecologically diverse farms bounced back faster than their monocropped neighbours.
A study by the University of Nebraska indicates that over time, more diverse farms have 70% more yield stability year in, year out, than monocropped farms. In a future with unpredictable weather patterns, yield stability will become as important as productivity.
The World Agroforestry Centre’s work shows that diversified maize systems are 25% more productive and 50% more profitable over the long term.
Agricultural biodiversity can also help farmers adapt to climate change. By focusing on a few major staple grains, we have ignored crops that are more resilient to climatic variations. For example, millet and sorghum are much more drought-tolerant than wheat and maize — but little research has been done to improve their yields or to develop good agronomic practices for these crops. Andean grains, are also more drought tolerant, yet — until the quinoa boom — were practically forgotten by research.
Past productivity gains were fuelled by plant breeding breakthroughs. Further discoveries will be vital for future productivity AND sustainability gains. There are 7 million accessions in 1750 genebanks around the world, mostly of major crops. But, there is important diversity in farmers’ fields and in the wild that we will need to find new varieties that are resistant to pests and diseases, that can withstand climatic shocks and stresses, and that can continue to enhance the productivity and resilience of our global food and agricultural system.
M. Ann Tutwiler
Email: M. Ann Tutwiler
Photo: M. Ann Tutwiler, DG Bioversity International, John Atkin, COO Syngenta, Richard Munang, UNEP Regional Climate Change Programme Coordinator, at Feeding the World 2014. Copyright: The Economist. Used with permission. The original photo can be found 
here.