A new study out of Iowa State University confirms that industrial agriculture (please don’t call it farming) continues to squander the precious topsoil on which its existence — and ours — depends. This is a problem that has nothing to do with global climate change, or peak oil, but that may hit us all harder and sooner than either. The bad news in the study is that the losses of topsoil are stunningly large. The other bad news is that they are getting worse, despite billions of dollars’ worth of “conservation” efforts. There is no good news.
The study looked at sediment deposition in 32 Iowa lakes, in the heart of the breadbasket. Among other things, they consulted the geological records, and found that prior to 1950 it took nearly two years (631 days) to deposit a millimeter of mud on a lake bottom in the area. After 1950 and the industrial-agriculture revolution, it took about two months (59 days).
This echoes a statistic from the US Geological Survey that, when I first saw it, put me through all the stages of grief except acceptance: since the 1950s, for every ton of product delivered to market, industrial agriculture has destroyed, on average, seven tons of topsoil. The rates of destruction in China and Russia are much worse. A separate study, also done in Iowa, measured topsoil losses from individual fields, in single thunderstorms, of up to 100 tons.
Even more distressing is the headline of the Iowa lake study: “Sediment Losses to Lakes Accelerating Despite Agricultural Soil Conservation Efforts.” What? Billions of dollars to encourage no-till, stream-buffer, low-impact, no-plant, cover-crop, rotational ag and the topsoil losses are still accelerating?
There are other serious issues here, separate but not distinct from the topsoil losses, because of what is carried with the topsoil. The silt itself, in large quantities, smothers aquatic life, but the pesticide and fertilizer residues that ride with it do even more damage. The pesticides kill (or affect reproduction) while the nutrients stimulate algae growth, which also kills.
Oh, and the other bad news: this study does not take into account the topsoil lost to wind. That, according to the US Soil Conservation Service, is about one quarter of all erosion loss. As the drought in the midwest and southwest gets deeper and longer, that statistic is not going to improve, either.
Sensible, sustainable farming can not only stop topsoil loss, it can reverse it. A stable, growing, living soil is much more resistant to drought, as well as flood and wind. Industrial, government-coddled agriculture cannot stop erosion loss and cannot grow topsoil. So who is going to starve soon, and who is going to be all right?
The answer is blowin’ in the wind and flowin’ in the water.