Peak Soil

Food is less nutritious than it used to be. Compared to values from 1950 (the first year for which there are data), nutrients in crops have declined up to 40%. For example, a serving of broccoli eaten in 1950 had significantly more vitamin C, B vitamins, calcium, and other nutrients than the same size serving of broccoli eaten today. In other words, to get the same nutrients today, you’d have to eat up to 40% more food.

The Organic Center report that describes this degradation notes that although organic produce is more nutrient dense than industrial produce, nevertheless organic nutrient density has also declined. Productivity is the cause cited in the report: growers are driven to increase the yield of crops from each acre. But as plants grow faster and bigger, plant metabolism limits the rate of nutrient uptake.

Increasing yields is driven by economics: get the biggest bang for a buck. In this case, the bang is a head of cauliflower or other food crop.

There’s another and more disturbing limitation that’s discussed among soil scientists: peak soil.

The idea of peak soil borrows from the idea of peak oil: oil as a finite resource extracted to exhaustion; soil as the source of crop nutrients as a finite resource also extracted to exhaustion. The soil scientist David Montgomery observes that while the threat of disappearing petroleum is well understood generally, “a crisis in global agriculture remains hidden: we are, and have long been, using up the supply of topsoil we rely on to grow our food.”

Montgomery argues that not just industrial agriculture, but agriculture based on tillage—that is, the plowing of the soil—is responsible for the degradation of soil ecologies in two ways. First, it literally opens the ground to erosion from wind and water so that the nutritious topsoil is blown and washed away. Second, the soil ecology that transforms mineral dirt into usable nutrients and that cooperates with plant root systems in supplying plants with those nutrients is torn asunder then blown and washed away.

Although historically the yield of each acre put under the plow has increased since the introduction of agriculture 10,000 or so years ago, that general fact ignores wide areas that were once productive but are now barren because of tillage-based agriculture. Montgomery and his colleagues warn that those times are coming to the current breadbaskets of the world and sooner than we’d like.

So on the demand side, food is less nutritious because of industrial agriculture that artificially increases crop yields so that the plant’s capacity to take up nutrients from the soil is outstripped by its growth rate. On the supply side, tillage strips away nutrients available to crops.

As I’m sure you can imagine, there are a number of more-of-the-same answers to this problem. One is referred to as remineralization: cook up nutrients in industrial labs and add them to dirt. Unfortunately, those nutrients are finite resources themselves: at some point, we’d run out of them. Another solution is genetically engineered crops that are more efficient at extracting nutrients from soil. Aside from the fantasy that GMO will feed the world with little more than PR for scientific evidence, it does nothing for the health of the soil itself.

The sane answer is what’s referred to as agroecology: the design and management of food systems based on ecological integration. A lot’s packed into that, but practically what it says is that agroecology is a technology used to grow and distribute nutrient dense food, integrates the farm into the local culture, political economy, and ecology, and improves and maintains the health of the soil.

This isn’t a fringe idea. The UN Special Rapporteur on the Right to Food says that the new Green Revolution is agroecology.

 But that’s not the direction in which feeding the world is headed. For example, there’s an organization called Peak Soil Indexes that is creating what it calls “investment opportunities” for the purchase of farmland as a commodity. Since the financial crisis of 2009, investment capital has flooded the Third World, especially Africa, to buy up farmland from small farmers. As a consequence, farm productivity has dropped.

Why is that?

Because investment capital isn’t interested in tending the land and growing food. It’s interested in growing money. Farmland has become one of the latest speculative bubbles. Productivity drops either because land is taken out of production or because any farming that takes place is industrial farming—you know, the kind that’s hell on wheels for degrading the nutrient value of crops and the soil from which they grow.

It turns out that worldwide, small farmers produce 70% of food on 25% of the land. That is, of all the land in the world being farmed, one quarter (25%) is cultivated by small farmers. Those small farms produce over two-thirds of the food people actually eat.

Many of those small farms use traditional methods that approximate agroecological practices.

So although nutrient degradation and peak soil appear as technical problems, as being about agricultural practices, as being about the adoption of ecologically sane technologies by farmers, in fact nutrient degradation and peak soil are problems of political economy. What I mean is that the politics are not about encouraging the right kind of technology but about making sure we have the right kind of land ownership.

And if you think this is exclusively a Third World problem, think again. The speculator’s friend Peak Soil Indexes is all about finding farmland investments in the United States, a speculative bubble that is expected to make half of all small farms disappear over the next decade.

More nutritious food? Feed the world? Sure thing. Shop agroecology. Grow your own agroecologically. Organize against industrial agriculture.