ChewsWise Blog

ChewsWise Blog

Is American agriculture really efficient?

Last week, I attended the Sustainable Foods Institute, hosted by the Monterey Bay Aquarium. As in the past, the session-packed affair of panels and keynotes did not disappoint, even though the outlook -- for fisheries, for food production, for humanity in general -- was pretty sobering.

Among the speakers was Jonathan Foley, a professor of ecology and director of the Institute of the Environment at the University of Minnesota. He gave a big picture view, noting that agriculture is not only the single biggest factor in global warming but obviously crucial to feeding a growing world. If there was one surprising takeaway, it was that the highly efficient machine of American agriculture -- and modern agriculture in general -- doesn't measure up to the hype. As Foley stated, "yields from the Green Revolution have stagnated and what we're doing isn't sustainable anyway."

This discussion of how to feed the world often begins and ends with the question of whether we're maximizing crop production per acre of land -- something American farmers do quite well. But what yield doesn't tell us is whether that land could be used even more efficiently to produce more calories of food. Foley pointed out that crops such as corn and soybeans which are then fed to livestock -- or cars -- amount to a grossly inefficient use of land resources. "The elephant in the room is the cow," was the way he put it.

Measured this way, it takes 32 pounds of corn to produce a pound of fillet mignon -- a 3% conversion rate of the calories in feed. (He specified that he was talking about muscle meat, not the leftover parts of the animal that are rendered.) What happens to the other 97% of the calories? It is wasted by this grossly inefficient calorie producer --  the cow. Only 15% of the the Midwest's grains are consumed by humans. "We throw away five-sixths of what we grow," he said. This isn't a rap on farmers, for they are doing precisely what the market or government signals them to do and are quite good at it. The question Folely was raising was whether the entire aparatus is the best way to produce calories for growing populations on a finate amount of land.

Now, I have, on occassion, enjoyed a good steak, but if was clear from his presentation that if the world feasted on steak, as growing numbers of people are doing, there would not be much of a world left. (He also noted that this equation would be different for a cow raised on pasture, since forage grasses cannot be directly consumed by humans. The measurements were less dire for dairy, eggs and poultry which are more efficient at converting feed to calories.) 

While farmers and researchers focus on improving yield, the entire equation is actually stacked against the efficient use of land because the process in the end is so wasteful. He noted that 10 percent of the world's cropland is in GMOs and yet even those yields have stagnated. And since these crops grow animal feed (corn and soybeans) and fiber (cotton), "they're not feeding the world's poor," he said.

Water is another wasted resource, with the differences in efficiency between Israel and India differing by 100-fold. Recall that highly efficient modern drip irrigation was developed in Israel because water is such a scarce resource.

Foley also noted that organic farming still represented a minute fraction of agricultural production, and suggested a middle way in which organic methods would be used but augmented by targeted use of chemical inputs, not unlike taking medicine when you're sick. The better path is to stay healthy, only relying on medicine when needed. He likened the modern model of agriculture to a constant IV drip, an apt metaphore considering the use of sub-therapeutic antibiotics in animal feed.

"I want organic to be the default farming method if we can pull it off," he said, but he noted that no one has a monopoly on the discussion. Useful solutions will have to come from both conventional and organic methods (which I've seen in the adaptation of organic methods by conventional farmers because they can be cheap and effective). 

The bigger issue, though, is that forests are being razed to grow crops, especially in Brazil and Indonesia. This burning of forests is by far the greatest contributor to greenhouse gas emissions that agriculture emits -- and agriculture alone accounts for 30-40% of greenhouse gasses. Transport of food doesn't even come close. If this land is then used to grow soybeans, as it is in Brazil, these dramatic emissions are created in order to feed this inefficient livestock machine, which is another potent contributor to greenhouse gas emissions. 

So what might be a better use of land?

"Potatoes," said Charles Mann, the author of 1491 and its sequel, 1493: Uncovering the New World Columbus Created (I highly recommend both books) in another talk. Not only do potatoes produce more food calories per acre than wheat and corn, but unlike most of the corn crop, potatoes are also eaten by humans. That made me wonder whether diets could change enough to alter the current food paradigm. In the following slides, in which Mann laid out the globalization of food trade 400 years ago, it was clear they already had. Potatoes originating in Peru were the direct cause of Europe's early 19th century population boom, the Irish potato famine notwithstanding. The sweet potato even reached China, where it is now widely eaten. Staple diets, in other words, can and do change.

If Foley, though, was implicitly pointing to a more vegetarian diet, he did not explain how we would get there. That he gave us only two decades to fix the current dire state also left me scratching my head about how such rapid change could be achieved. I doubt whether people with the money will forgo a steak for a potato (they tend to want both), unless there is a dramatic reworking of incentives. But it was clear from Foley's talk that those sorts of cultural changes -- rather than simple agricultural science aimed at boosting yield -- will need to be part of the equation. "The choice is between the world we've had and the world that should be," he said. But he left open the question of how we will actually get there.

- Samuel Fromartz