By David R. Montgomery
Book Report by Ed Schein
Geomorphologist David R. Montgomery loves soil. Two previous books, The Hidden Half of Nature: The Microbial Roots of Life and Health, and Dirt: The Erosion of Civilizations, set the stage for his latest endeavor, a world-wide tour to farmers of our planet who are practicing a new philosophy of farming that merges ancient wisdom with modern science. If you think carbon capture on a scale to reduce global warming is not possible, READ THIS BOOK!
Here are some chapter teaser quotes to open this subject. “Civilization itself rests upon the soil.” – Thomas Jefferson. “A nation that destroys the soil, destroys itself.” – Franklin D. Roosevelt. “The plowshare may well have destroyed more options for future generations than the sword.” – Wes Jackson. “When people are poverty stricken and starving they pass on their suffering to the land.” – Rattan Lal. “If herbicides are so good, how come we still have weeds?” – Gabe Brown. “All is not butter that comes from the cow.” – Yiddish proverb. “A person with a new idea is a crank until the idea succeeds.” – Mark Twain. “All things come from the earth, and all things end by becoming earth.” – Xenophanes.
As some of these quotes suggest, the plow is our worst enemy. Montgomery says to go to any rural cemetery and see how its elevation is several feet higher than the surrounding farmland. We are mining the soil and not rebuilding it. Farmers who are restoring life to their land said they had increased the fertility of their soil and restored profitability to their farms by walking away from conventional practices.
- Myth: Industrialized Agrochemical Agriculture Feeds the World Today. Almost 72% of all farms worldwide are smaller than 2.5 acres.
- Myth: Industrialized Agrochemical Agriculture Is More Efficient. Well-managed alternative farming systems nearly always use less synthetic chemical pesticides, fertilizers, and antibiotics per unit of production than conventional farms. We burn ten calories of fossil fuel to grow one edible calorie.
- Myth: Intensive Agrochemical Use Will Be Necessary to Feed the World Of Tomorrow. Adding fertilizers to already fertile soils does not really boost crop yields. How can we get enough organic manure to replace chemical fertilizers? Grow cover crops, especially nitrogen-fixing species, as green manure.
Why plow? To get ahead of weeds. But plowing disrupts underground organic processes that allow plants to defend themselves and to get help from beneficial microbes. The answer? No-till farming workshops by Guy Swanson. He says fertilizer salesmen are like drug dealers. Plants need a soil rich with decaying organic matter and nutrient prospecting and recycling that microbes provide. No-till equipment cuts fertilizer and diesel use in half, as well as stopping run-off of all the nitrogen & phosphorus that crops don’t take up. But better still, wind can’t dry out and blow away no-till fields.
So, what is conservation agriculture? Minimum disturbance of the soil; growing cover crops and retaining crop residue so that the soil is ALWAYS covered; and use of diverse crop rotations. This can apply anywhere, on organic or conventional farms, with or without genetically modified crops. One Japanese farmer’s recipe for plentiful harvests with less work was to cooperate with nature and schedule planting and harvesting so that each crop would set the stage for the next. Fields occupied by desired plants deny weeds the chance to get started. But the key is to use all three conservation principles. Today, about 11% of global cropland is under conservation agriculture. About 42% in South America, 34% in U.S. & Canada, but just a few percent in Europe, Asia, and Africa. South Dakota is the best example of going from almost all tillage in the 1990s to more than three-quarters no-till by 2013.
At no-till farms, corn stubble protects and encourages worms to drag crop residue down their holes four feet deep, providing soluble nutrients and allow water to sink into the ground.
How does conservation agriculture relate to carbon capture? Grazing by cattle chewing, tearing, and trampling plants that must then heal by pumping a steady supply of carbon-rich exudates out of their roots to recruit microbial assistants. This builds fertile grassland soils. Imagine 700 cows clumped together, grazing lush foot high grass for just a few hours, then moved to the next paddock. No weeds are left as cows compete with each other and are protected from predators. Then the area is left to regrow for a full year. This high density grazing by buffalo is what built our lush prairies. Global expansion of grasslands and grazing animals over 40 million years and spread over 40% of Earth’s landmass could have decreased atmospheric carbon dioxide levels, reducing temperature levels enough to help trigger recent glacial periods that most know as the Ice Age. Compare this to the world’s agricultural soils losing 66 to 90 billion tons of carbon, mostly due to tillage and resultant erosion. Restoring U.S. cropland fertility could sequester enough carbon to offset emissions from half of the cars in America.
There are many more ideas from farmers for conservation agriculture in this book, but the key is educating young generations of farmers that conservation agriculture is much easier and cheaper on smaller farms than on large spreads. A novel program in England to save family farms paired farmers nearing retirement with young people who wanted to be farmers but couldn’t buy a farm. A North American version could be a 21st century Homestead Act. But restoring the soil can be a 20-year solution, not 200 years. SOIL CAN BE BROUGHT BACK TO LIFE!