Sustainable Food from the Ground Up

I think it's safe to say that almost everything we eat is, at some juncture, connected to the soil. Sure, there's some hydroponic operations out there that sidestep dirt, but by and large everything, be it corn-fed chickens and cows, any of the unrecognizable processed foods that Micahel Pollan refers to as "food-like substances", and so on, eventually links back to the soil. Therefore, as long as we plan on eating, and especially if we plan to eat sustainable food, we need to keep our soil healthy.

Currently, our soil is in a sad state. Years and years of industrial agriculture has eroded vital topsoil and depleted nutrients. Topsoil is the outer 2-8 inches of soil that supports all plant life. Plants derive most of their water and nutrients from this important layer, which is, at its best, laden with microorganisms and organic matter.

Most agriculture uses tilling techniques using big machinery that makes quick work of tilling large fields. The problem is that this technique digs deep into the soil, displacing the rich topsoil and setting the stage for erosion. Erosion is nothing new to big agriculture. Remember hearing about the Dust Bowl in your U.S. History class? The great American dust storms of the 1930s were in large part due to poor farming techniques that didn't employ crop rotation, cover crops, or other anti-erosion measures. Once the topsoil is removed or blown away, it's really difficult to rebuild it to its original nutrient levels. The best way to prevent erosion is to practice "no-till" farming. Even though it requires further investment in seeding equipment, farmers who are concerned with sustainability are making the switch to no till with the hope that it'll pay off in the long run.

And it usually does. After the initial switch to no-till (also called conservation tillage,) farmers can expect to reap the benefits within the next few years. These benefits go beyond preventing erosion to actually rebuilding the soil. Because the soil isn't torn up by big machinery, there is less soil compaction, and higher water retention, and the accumulation of organic matter and aggregates that enrich the soil. So far, this technique is rarely used on a large scale, but it's an action that many small and mid-sized farmers are taking against further soil degradation.

The continued removal of topsoil means that more nutrients must be added to the stripped dirt if it is going to be rendered productive. For the bulk of our agriculture, the soil is only usable if inundated with petroleum and other non-renewable resource-base fertilizer inputs. The only way to move away from the dependence on these heavy-duty inputs is to rebuild topsoil.

Our food comes from the soil. We want sustainable food, we support sustainable agriculture, but we need to remember that sustainable agriculture is dependent upon soil that is managed sustainably. Otherwise, it's only a matter of time before more topsoil bites the dust.

Photo Credit: CC BY 2.0