Sunday, July 17, 2011

Whose Side is Science On?

The kids and I went to the Saskatchewan Science Centre this morning. The soap bubbles were a big hit, as was the mirrored table where you could create kaleidoscopic images with coloured plastic shapes. Lest you think my kids are Luddites, I hasten to assure you that they were also enthralled by Richardson's Ag-Grow-Land, which "celebrates the science and cutting edge tools of modern day agriculture in Saskatchewan": the exhibits had buttons to push and levers to pull.

In one agricultural exhibit, you can climb inside a John Deere tractor cab and have the virtual experience of growing a crop - choosing tillage methods, when to apply chemicals and fertilizers and how much, that sort of skilled technical decision.

I have a friend who is a rural sociologist. Her father is an organic farmer. She decided to play the game and farm organically. Turns out she wasn't offered the chance to cover crop, use green or animal manure, intercrop, or any other organic or agroecological methods. She ended up with the worst score of anyone in the game.

Well, maybe that's scientifically valid. Surely the Science Centre would have vetted its sponsored exhibits for scientific veracity. Let's see, shall we?

Your farming performance, based primarily on yield, is rated against previous players at the end of the game. I have some problems with the equation of good farming with yield, but let's accept that assertion for now. How do the yields of organic agriculture compare with those of conventional agriculture?

The answer, of course, is "it varies", based on type of crop, region, how long the land has been in organic production, and specific weather events that might occur. But for many crops, organic yields are quite close to conventional yields. A twenty-one year European study found an average yield of 20% less for organic, but this ranged from 10% less for winter wheat, no difference for grassland yields, and 33% less for potato yields mainly due to a potassium deficiency. Another twenty-one year trial in Pennsylvania found similar yields for corn and soybeans in both methods. 

So if the entire world switched to organic agriculture, would that mean a reduction of 20% in food supply? Of course not. Much of the world's production, in developing countries, shows drastic yield increases with the adoption of agroecological methods. Drastic, like tripling yields of grain in Honduras just by cover cropping. Reviewing several studies, Altieri* found that "integrated farming systems in which the small-scale farmer produces grains, fruits, vegetables, fodder and animal products out-produce yield per unit of single crops such as corn (monocultures) on large-scale farms." Studies in Mexico found that it takes 1.73 ha of maize monoculture to produce as much food as 1 ha of mixed maize, squash and beans.

Another post will have to address all of the additional benefits of organic farming found in these studies and others, including 30% fewer fossil energy inputs, increase in biodiversity, more resilience to weather shocks, greater water retention and nitrogen and carbon levels in soil, and waste recycling.

The divide between conventional and organic methods isn't as clear-cut as Richardson et al might like you to think, of course. Conventional farmers increasingly use organic methods such as cover cropping, or planting a legume in rotation to increase nitrogen in the soil. What is clear is that agribusiness benefits from positing conventional, chem-dependent methods as not only normal, but examplars of scientific progress. Hey - you aren't anti-science, are you? Against progress?! 

Luckily, agroecology is cutting-edge science, both physical and social. And smart farmers, if they can find out about them, will adopt methods that work.

And, luckily, if you take your children to visit the Science Centre, you are armed with some data to help them critically think about what they're seeing.

*Altieri, Miguel A. and Victor Manuel Toledo. (2011). The agroecological revolution in Latin America: rescuing nature, ensuring food sovereignty, and empowering peasants. Journal of Peasant Studies, 38:3.

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