Agroecological zones and climate

Much of my research on climate change and agriculture over the past year has focused on how innovation-- mostly biological, such as plant breeding, but also technological, such as irrigation-- has expanded the range of certain crops, such as wheat and soybeans in North America. Looking at these historical cases, we might be able to learn something about adaptation of crops to new climate zones due to climate change.

The Consultative Group for International Agriculture (CGIAR) has also picked up on this idea of climate adaptation through crop innovation. This makes perfect sense, given their historical roots in plant breeding, and their access to large repositories of plant genetic material around the world. They have lately focused on bridging gaps between climate modeling, plant breeding, and climate-tolerant crops. For example, if we can predict that the climate in Nepal is going to be similar to Bangladesh in 20 years, then Nepali farmers and plant breeders should be not only learning from their Bangladeshi counterparts, but also starting to grow Bangladeshi varieties of rice.

But Bangladesh alone has about 30 agroecological zones (see figure above). Agroecological zones are based on regional soil types and climate zones. This means that farmers in each zone are likely to differ, even if by just a little, in the type of irrigation they use, variety of crops they grow, and when they plant and harvest those crops. Agroecological zones are also useful in categorizing the maximum yield productivity of a region-- for example, rice just might grow better in certain zones.

Today many crops have mixed genetic heritages that span not just countries but continents, and we can even grow traditional Japanese rice in Australia. If we look back to the Green Revolution, Norman Borlaug introduced a variety of wheat to India that was originally bred in Mexico. Borlaug also innovated a plant breeding technique called "shuttle breeding," which is where you test a new crop in two different climate locations. This would make the plant "hardier" and able to survive in a larger climate zone.

The problem lies in reducing agriculture to a simple equation of climate and genetics. The CGIAR is falling a bit too closely into a "Seeing Like a State" mentality. The drive to simplify and cross-apply broad agricultural knowledge across regions ignores many local factors, both biophysical (types of local insects, soil salinity, climate variability) and social (gender roles in farming, innovativeness, access to resources).

I've written about these generalizations of climate vulnerability before, and how such generalized information is likely limited in its use. Climate change is not the only challenge to farmers: in fact, short term climate variability may be more important. Miguel Altieri and other agroecologists argue that local networks of agrobiodiversity and seed sharing are more important than international efforts to improve yields through modernization of agriculture. On the Agricultural Biodiversity Weblog, an author writes about the problems with using recent online climate-zone tools produced by the CGIAR and FAO.

So despite my skepticism about the usefulness of climate models and technological fixes, I'm extremely excited to work on this issue more in the upcoming year, and especially looking at farmer participation and innovation for climate adaptation in India.