INNOVATIONS IN AGRICULTURE
October 15, 2012
Three Cheers for Expensive Oil
By DAVID R. MONTGOMERY
A version of this article appeared October 15, 2012, on page R4 in the U.S. edition of The Wall Street Journal, with the headline: Three Cheers for Expensive Oil.
Scarce oil may be one of the best things that could happen to agriculture.
To understand how that could be, consider two facts. First, agriculture uses a huge amount of energy—almost a fifth of the total consumption in the U.S. alone. And second, farming as we know it erodes fertile land far faster than nature can replace it.
Now, thanks to steep rises in oil prices, growers are adopting practices that use less fuel. As a tremendous side benefit, these methods not only fight erosion but they build soil and enrich it with nutrients crops need. In fact, I'd argue that for perhaps the first time in modern history, the short-term incentives for individual farmers are aligning with humanity's long-term interest in conserving the soil and its fertility. It's a potentially huge change that could reshape farming as we know it.
Here's a look at two of the most rapidly growing and effective practices already in use and another that may take off soon.
Ditching the Plow
The most popular fuel-reducing strategy involves a radically new way of planting seeds. Instead of breaking up the ground with a plow to plant seeds, no-till farming leaves the remains of last year's crop on the surface. Drills punch through this mat of vegetation and insert seeds into the ground.
Ditching the plow can cut fuel consumption by as much as half, bringing substantial savings. It also reduces the need for expensive fertilizer. Specialized machinery can inject fertilizer along with the seeds, putting just enough right where developing crops need it most.
Those savings help explain why farmers have been moving to no-till, and why even more will as the cost of oil rises. But the side benefit of this shift will be alleviating a problem that's been plaguing humanity for thousands of years.
Plowing removes plant cover, and bare fields erode 10 to 100 times faster than shielded soil, far faster than nature can make more. Overplowing has stripped whole regions bare and helped bring down past civilizations. Parts of Syria that were extensively farmed in Roman times are now bare, rocky slopes, for instance, and in southern Greece you can still find ancient agricultural tools scattered on hillsides that can no longer support cultivation.
Modern industrial societies aren't immune. Islands of unplowed prairie in pioneer cemeteries across the American heartland stand higher than the surrounding, eroded fields. On some corn fields in the Midwest, I've seen soil that was so degraded it looked like beach sand.
No-till farming can change all that. The practice can reduce erosion by more than 90%, and bring soil loss close to the pace of soil production. Over time, no-till can also increase soil organic matter and boost microbial activity that helps cycle nutrients from the soil into crops and back again. And not plowing helps reduce runoff, leaving more water in the ground where it's available to crops.
Feeding the Earth
The next strategy involves reducing reliance on fertilizers that don't enrich the soil and require a lot of oil to manufacture. Instead, low-cost organic matter like manure, crop stubble, garden trimmings and even household food scraps are used.
This certainly isn't a new idea. Centuries ago, the Dutch reclaimed land from the sea and enriched it with organic wastes. Long before then, farmers from China to Peru improved their soils by returning organic matter to their fields.
But in the U.S. and Europe, organic sources of fertilizer fell out of favor in the middle of the past century. There are a lot of reasons, some of which don't have anything to do with agricultural effectiveness. Big crop subsidies led many farmers to stop keeping livestock, which meant no more on-farm manure. And after World War II, former munitions factories started cranking out cheap fertilizer, which together with cheap oil made animal husbandry an expensive, labor-intensive anachronism.
Intensive chemical-fertilizer use also dramatically increased crop production, especially on already-degraded land, during the Green Revolution that has helped feed the world's rising population. But the cost of fertilizer is tied to the price of oil.
With the price of manufactured fertilizers rising, recycling organic matter is becoming more cost-effective. It also can build fertile soil. While chemical fertilizers won't disappear from agriculture anytime soon, rising prices will make it increasingly attractive to rebuild soil fertility using organic matter, particularly on the third of the world's cropland already degraded beyond use.
Spurred by high fertilizer prices, some farmers are bringing livestock back onto their land. One energetic couple in Missouri told me how they used chicken and goat manure along with intensive composting to turn an abandoned farm with degraded soil back into a productive and profitable working farm in under five years.
It's not just conventional farmers who are adopting these methods. Some cities are setting up community food gardens to help counter rising food prices. These urban farmers see recycling organic waste as the key to growing fresh, affordable produce in cities, where most of humanity now lives.
I saw this for myself when I visited one such garden built atop a reclaimed landfill near downtown Seattle. Looking at the oversize vegetables and digging my hands into rich fertile soil, I could hardly believe this farm was started less than a decade before with trucked-in, sterilized dirt. Regular additions of compost rapidly turned this small patch of land into a reliable source of fresh fruit and vegetables for residents and local food banks.
Putting Down Roots
The final alternative strategy isn't here yet. But when it arrives, it has the potential to change the way American farmers harvest the country's third-largest crop: wheat.
The Land Institute in Salina, Kan., is developing a range of perennial grains that would make annual plowing unnecessary. To my mind, the most revolutionary efforts involve a version of wheat that can be used in many of the same foods as the regular stuff.
Harvesting perennial wheat would mean fewer passes with the tractor and less oil burned. Meanwhile, the longer roots of perennial wheat reach deeper into the soil, tapping into more of the water it holds, increasing crop tolerance to drought. Longer roots also enhance nutrient uptake, further reducing the need for fertilizer.
There's a dramatic illustration of the idea hanging in a stairwell at the Land Institute: a life-size picture, close to two stories tall, of a perennial wheat plant and its Rapunzel-like roots. Next to it, a picture of a conventional wheat plant looks anemic by comparison, its roots reaching down just several steps.
Perennial wheat also has the potential to do long-term good. Harvesting the wheat would leave the plant and its root system in place, storing a lot of organic matter below ground, where it helps support the growth of the next crop. Minimally disturbed ground, reinforced by interlaced root systems, also means far less soil erosion.
To some, I'm sure that all this speculation about a revolution in farming sounds naively optimistic. But the movement toward these new methods is already under way, and the economic case for more farmers to adopt them will only get stronger as oil and fertilizer get pricier.
Let's hope so, for our descendants will need productive, fertile soil just as much as, if not more than, we do today. And what we now consider alternative methods of farming are some of the best ways to ensure that they'll have plenty of it.
Dr. Montgomery, a professor of geomorphology at the University of Washington in Seattle, is the author of "Dirt: The Erosion of Civilizations." He can be reached at reports@wsj.com.
