Can Soil Replace Oil as a Source of Energy?

Posted in Scientific American Magazine online, April 5, 2103

Excerpted from The Upcycle: Beyond Sustainability—Designing for Abundanceby William McDonough and Michael Braungart. Copyright © April 16, 2013, North Point Press.

Food as a battery—that is what we would like you now to consider. But before we get to the full expression of that proposal, we need to review exactly how batteries function, so you can appreciate the beauty, and potential innovation, made possible by thinking through this metaphor.

Batteries are not storage containers for electricity, as one might assume. They don’t provide power because somehow someone pumped in the electricity and locked it in, and now it’s ready for use. Instead, they contain the potential for an electromagnetic reaction, which, if engaged, creates power. The battery consists of a negative solution (the anode) and a positive solution (the cathode) separated by the ions of the electrolyte. The extra electrons in the anode want to move to the cathode, but there is no path through the electrolyte between them.

When a wire connects the negative end to the positive end of the battery, the electrons can flow through the wire, seeking their harbor in the cathode. These free-flowing electrons, in the middle of that path, power your flashlight or start your car.

The beauty of a battery is that it is potential energy, ready for your use, when and where you need it. Should the battery run out of charge, its power is recharged by reversing the process, forcing the electrons from the cathode into the anode. Then you can start again using your battery to provide electricity.

Now think of how humans conventionally create energy. We burn fossil fuels—i.e., carbon-based organic compounds (as we have said earlier, fossil fuels are ancient organic compounds)—and inadvertently turn them into carbon dioxide, among other things.

Photosynthesis is an electromagnetic reaction that frees electrons from water to turn carbon dioxide into organic compounds.It is the reversal of the burning of fossil fuels. It is recharging the battery. It is recharging our power source. If people don’t allow the recharge of that battery, the world can’t recapitalize.

If one looks today at our organic battery, this biosphere, which has provided all the energy that people have used for their needs for millennia (the fossil fuels in coal and oil; the biofuels in wood), one might begin to understand the importance of recharging. Human beings have every reason to want to do so.

Get Down to Earth
Let’s look at the common worm. As a worm makes its sinuous way through the soil, it aerates, tills, plows, and fertilizes. Of course, it doesn’t intend to do these things, but it seems to have been designed, by nature, to have beneficial effects in the course of every single thing it does.

Worms are avid consumers. They eat their own weight in food each day. Yet they are enormously helpful to ecosystems (our use of “yet” indicates how much people have come to associate “consuming” with destruction and waste, which is certainly not the case in nature). Worm castings—what they leave behind—are “waste” only for a moment before they become “food”: These castings are rich in nutrients, extremely rich—they contain higher levels of nitrogen, phosphates, and potash than the soil around them. The lowly earthworm is one of the planet’s most valuable creatures (and apparently one of Darwin’s favorite organisms).

Compare this highly effective and evolved interaction with soil to humanity’s most recent interactions with soil. Humans have the capacity to be similarly effective as earthworms. One way is to add nutrients, and we could easily do so, but so far, for the most part, we aren’t.

How can we do this? The history of the development of the technical battery over time has been one of experimentation with various substances to sustain the longest charge and promote the most powerful chemical reaction needed to create the flow of electrons; to reduce the size and cost of the battery while optimizing the duration of its energy output; and to create specific batteries for specific products and needs.

To translate this to the earth battery: We might create farming techniques that sustain the longest period of productivity, augment the soil for optimal plant growth, utilize soil in the most compact way, and diversify the design of that growth for different locations.

Right now in human history, we have designed and implemented a system that puts us in danger of expending our earth battery. Carbon is not treated as a valued asset by human industry. People do not feed the soil. Since the founding of the United States, the country has by some accounts depleted 75 percent of its topsoil. Most of this loss is caused by now questionable modern agricultural techniques—monoculture (growing one kind of crop year after year, so the same nutrients are siphoned out), overtilling (which encourages topsoil to become airborne and erode), and salinization of soil caused by overwatering and overuse.

One hundred and fifty years ago, the Iowa prairie had 12 to 16 inches of topsoil, as well as the carbon stored in the deep roots of prairie plants, which were as much as 15 feet deep. Now the topsoil is down to 6 to 8 inches. Soil production takes significant time; it can require from 100 to 500 years to create one inch of topsoil. With those kinds of numbers, human beings have little to no hope of catching up.

We are frittering away our future food. Some estimates for the United States show that 6 percent of wheat and corn production is lost for every inch of topsoil that disperses into the air or water. Or to put it in other terms, the United States is said to lose $125 billion worth of topsoil a year.

The problem is occurring around the world. The United States loses topsoil 10 percent faster than it can replenish; China and India are at rates of 30 to 40 times faster.

The quantity of loss isn’t the only problem. People are also depleting the richness of the soil that remains.

Norman Borlaug, the agronomist known as “the father of the green revolution” who won the Nobel Peace Prize in 1970, came up with revolutionary ideas about hybridization to optimize grains for higher yields. The Nobel selectors credited him with saving more than a billion people from starvation. But those green revolution concepts have now inspired industrial farming to escalate hybridization and genetic modification to the point that they are selling an herbicide to kill weeds and then crop seed that can resist the herbicide. The farmer is buying at least two different products—seed and herbicide—from the same corporation. Farmers have also become more dependent on soil additives, such as phosphate, which are customarily mined, requiring the farmers to go far afield—and certainly far from the field, even to distant lands—to maintain high local yields.

The green revolution has been enormously productive, but its focus has essentially been on gleaning energy from the battery without considering the optimized design of the organic battery, for how to maintain the charge. We think that human beings can be doing more to recharge their local earth.

Soiling the Planet: Give Back
The second thing we can do for our earth battery is optimize the soil to encourage electron exchanges. We can improve plant life’s access to needed nutrients in soil.

We are extremely interested in the alternate green revolution launched when Sir Albert Howard published his seminal An Agricultural Testament in 1940. He was an agronomist sent by Britain to India to inform the farmers about Western farming techniques. To his surprise, he found the Indian farmers functioning quite well. Their agricultural systems were focused not just on optimizing specific plants but on maintaining soil health—and, more specifically, on devising systems to sustain the microbacterial matter in the soil. One example: The Indian farmers were able to return difficult-to-break-down straw to their soil by putting it on their roads, crushing it with farm wheels, and mixing it with manure. Howard’s insights introduced the idea of modern composting and led to the beginning of the organic agriculture movement.

These advances play out today. As just one small example, Gary Zimmer, of Midwestern Bio-Ag, advises more than 3,500 farmers working approximately two million acres of farm—primarily in the Midwest, but reaching as far as Idaho and Pennsylvania—to build productivity from the soil up. He looks first at what the soil on each farm needs in biological nutrients. His techniques may create yields slightly lower than those created by the big agricultural companies, but the cost in soil amendments is also lower, so the profit can be higher. For farmers around the world, the idea of lower costs with higher profits probably sounds appealing. It’s common sense.

Our point is this: Many people believe that the next green revolution will be an offshoot of the Borlaug revolution—that it will come from optimized and modified seeds and plants, and certainly those developments will continue. But we believe the next green revolution may come from the soil. In other words, it may come from people trying to execute the optimization of the battery—the way the earthworm does. And all of this will be further amplified by greenhouse techniques such as hydroponics.

Phosphate: The Next Fossil Fuel War
Phosphate is one of the key ingredients in soil, in how the earth recharges itself.Plants require phosphate to grow. Animals, including ourselves, need phosphate for bones, teeth, and membranes—and we get that mineral from our food. Plants, clearly, get their phosphate from the soil, and in nature’s system they would return the phosphates to the soil when they die and decompose (or are redeposited as animal waste).

But humans have been implementing less-than-optimized practices. Through farming, people are removing high levels of phosphate from the soil—the plants take up the phosphate and are then carted off, leaving no remnants behind to “reseed” the organic phosphate.

Human beings also put the phosphate available in soil out of reach by overwatering. This does not dilute phosphate; it causes it to bind to other elements before the plants can uptake the phosphate in a form useful to them. In fact, the phosphate binds with so many other elements—silicates, carbonates, sulfates, and the like—that it can be a tricky nutrient to add to soil. One gardener has compared it to throwing a monkey through a jungle. The monkey’s tail and arms and legs catch on so many vines and tree limbs that it can’t get through.

The current solution to reintroduce phosphate to the soil involves dumping mined phosphate onto fields. But because phosphate links to so many other elements, it easily washes out of the soil and into groundwater, where it leads to the high nutrient content in lakes and rivers that subsequently creates algae blooms, killing off fish and aquatic plant life. Mined phosphate also tends to include radioactive elements, such as uranium, radium, radioactive lead, radon, thorium, polonium, and cadmium, because these are inescapable trace elements in phosphate ore extraction.

Plus, there is a geopolitical conundrum in the use of mined phosphate. The top two exporters of phosphate in the world are the United States and China, followed by Morocco. But in 2010, China, recognizing the importance of phosphate to its own agricultural needs, slapped a temporary 110 percent tariff on exporting phosphate at the cusp of the spring planting season. That left the United States exporting its dwindling supply. At current rates, the United States’ supply is estimated to be depleted in 30 years. That means the United States will be dependent on imports from Morocco or China—which could get expensive as tariffs fluctuate—much as nations are dependent on imported oil.

To come up with a solution for this phosphate requirement might sound like a daunting challenge, but the solution is not out of our reach. In fact, we all get to the bottom of it every day.


Read the full Excerpt on