Stone Age Agriculture
Farming with Glacial Gravel Dust
© by David Yarrow, 1988
I HAD NEVER EATEN A WHITE BEET BEFORE. I bit into its soft white flesh and rubbed it with my tongue. An eruption of flavor sent my eyebrows skyward. Startled, I lost Tom MacDonald's words as my awareness focused on this intense sensation. Best-tasting beet I had ever bitten.
This wasn't just a new variety of beet—it was grown organically. But even that didn't account for such magnificent flavor. This beet was grown with glacial gravel dust—from soil that had an abundant, full menu of minerals added to it.
In May, I had heard New York's Agriculture Commissioner declare, "Organic advocates want to turn back the clock 100 years." The Commissioner underestimated the scope of history: Tom MacDonald is an organic radical who set his watch back 10,000 years. Tom has begun using glacial gravel dust from the end of the last Ice Age with results so satisfying he's given up all other fertilizer.
In 1970, Tom and his wife Shelley discovered macrobiotics—a way of healing based on Oriental medicine and philosophy. After study in Boston, in 1974 they moved to Hannibal, New York near Lake Ontario to begin farming organically. Tom says, "I began organic farming as a way to produce good products and as a livelihood. In terms of the environment, it's the future. There's no point in farming chemically, because it's the past."
In 1978, the MacDonald's moved to Perry City in the southern Finger Lakes to 30 acres of level glacial till with a large warehouse. The former owner—a Cornell University agriculture professor nicknamed "nozzlehead"—had drenched the land with chemicals. To switch the fields to organic culture took several years, during which time Tom had to rent fields until the biological balances on his own recovered from their abuses. Tom still rents 20 acres, but plants only 25 and keeps the rest in green manure cover crops.
For several years Tom and Shelley marketed much of their produce I New York City's Greenmarkets, a network of farmers' markets in Manhattan. There, on the front lines of the food system, they dealt first hand with consumers who demanded flavor and freshness, and who wanted organic. Today, Tom manages a $120,000 per year, family-run, organic vegetable operation, yet remains almost broke. Land and equipment mortgages yield a heavy debt load, and other typical farm problems. Looking back, Tom reflects, "Farming organic meant a lot of costly experiments and lost time making mistakes, but my willingness to try things made me open-minded enough to try rock powder.
"Three years ago, 90 percent of our stuff went to Greenmarkets in New York City. Last year we sold to wholesalers in town and Northeast Coops in Boston because we didn't go to New York City. This year we'll do some wholesaling in New York. Unfortunately, it's still the same as 15 years ago, in that we export—we don't market as much locally as we could or should. I've tried to get out of that, but we'll have to go to big cities another three years before local markets open up."
SHELLEY FIRST HEARD OF JOHN HAMAKER FIVE YEARS AGO at a Natural Organic Farmers conference when Joanna Campe, publisher of Remineralize the Earth journal, talked on soil remineralization and the onset of a new glacial epoch. Later, they got Hamaker's book The Survival of Civilization.
Tom commented, "It was easy for me, because every spring I go in the fields and there are all these rocks, so I take them out. I always thought, 'This is stupid. This made soil, and here I'm taking them out, getting tired and sweaty.' From a mechanical point of view, rocks are tough on your equipment, so you remove them out of the way. But I knew it was silly, because they are the parent of soil. Those rocks were left by glaciers, and I always wondered about grinding them up. I said, 'Instead of taking the rocks out, I should grind them and put them back on the fields for fertilizer.' I wanted to do it years ago, but didn't know how or why."
Tom's first experiment with glacial dust was four years ago. He says, "First time we spread it on half a rutabaga field. We got some in our truck—had to shovel it—it was a drag. Four weeks later, I drove past and there was a line where I stopped spreading, and the rutabagas were four inches higher—nice and dark green. They grew faster with noticeable difference in size, color and taste—like they'd been fertilized."
Tom gets his dust from a gravel quarry nearby—a huge glacial outwash many miles big with water under it. Hamaker recommends glacial gravel over other rock because it's a mix of all types of rocks, assuring a supply of all elements. The quarry's big bucket scoop drops in the lake to come up with mixed rocks loaded on conveyors and crushed underwater because dust is an environmental pollutant. The washings settle out and are loaded on a truck, which Tom pays to haul and dump.
OUTSIDE, TOM SHOWED ME HIS DUST PILE: 12 feet high and 30 feet across. Pointing to weeds around the pile, Tom observed, "Everyone knows about fertility in compost. When you have a compost pile, rain leaches nutrients out of the pile. There's so much fertility, weeds grow high and green on the nitrates. The same happens around my dust pile. I let it sit a year, and the weeds say, 'Look, it's compost.' To me, it's impressive."
Hamaker says bacteria, fungi, algae, and other microlife trap and hold water and nutrients in soil. Glacial dust feeds this microbial life to assure a teeming population to provide a vest, invisible reservoir to capture and recycle nutrients, and maintain soil structure, or tilth.
Tom reports, "Soil scientists say if you have a bacterial explosion, you don't have to worry about nitrogen—your source is dead bacteria bodies. I've given up using other fertilizers. I used to buy rock phosphate in trade once in a while, but I haven't gotten any for three years. I can get what I want from rock powder. Soil scientists say to lime soil to get the pH up and add calcium, but it also supplies trace elements to stimulate bacteria. Everyone knows lime loosens soil."
Tom hasn't put it on all his fields yet due to problems spreading it. He reports, "ast year we sifted rocks out an spread it with a little hand spreader. It had to be dry. Sometimes we had to poke it through and it flew out. I hope to get better results this year. My neighbor's going to bring over his big manure spreader—he can turn his chain on fast and it'll flail out the back.
Due to problems with spreading, I'm not sure of my application rate. Last year I tried to get 5,000 pounds per acre, but I don't know. One farmer puts on 500 pounds each time he plants grain. To get results, you may have to apply as much as five tons per acre—my opinion after farming for 15 years and the dust for three years. But I'm sure it works to get a little on each year. Hamaker says you can dump 20-50 tons per acre—it won't hurt the soil."
It is necessary to fine grind the rock to increase the minerals exposed to bacterial action. A one pound stone has a surface area of 12 square inches. If ground to medium sand, its surface area becomes 3,200 square inches. As very fine sand, it's surface area is 16,000 square inches; as clay, 564,000. The smaller the size, the more rapidly bacteria can absorb minerals to build their protoplasm. Here, too, Tom has problems.
"I have varying particle sizes. Some of it will work fast—it's like clay—real fine. Then it goes up to sad size, but it's not silica. Supposedly it will go through 100 mesh screen, and some will go through 200."
Despite these problems, Tom says, "I'm real happy with it for very common sense reasons. I don't want to buy rock phosphate from Florida, or keep animals so I can grow lush produce. Bio-dynamic people grow nice stuff, but I can't keep cows and be their master—I'm not comfortable with it. But I need more of what manure would give me. This way, I get a similar response. And I believe trace elements are significant.
"Farmers give lots of attention to major minerals—nitrogen, potassium, phosphorus—and little to minor minerals, and a tiny bit to trace elements. Because they get results from NPK, they figured it was what we should do. But their results were unbalanced, producing unbalanced people. Now, we have to emphasize trace minerals—the least of the elements. You know, 'the least shall be first.' If they're taken care of, the others are all right, because there's plenty of nitrogen if you have live growth of soil micro-organisms."
IN THE SURVIVAL OF CIVILIZATION, HAMAKER WROTE, "...in 1977, corn grown on soil mineralized with glacial gravel screenings was tested along with corn from the same seed grown with chemical fertilizer. Mineralized corn had 57% more phosphorus, 90% more potassium, 47% more calcium, and 60% more magnesium than chemical-grown corn. Mineralized corn had close to 9% protein—very good for hybrid. All nitrogen in mineral corn (whose content is an indicator for protein) came from the air by way of biological processes, and was in amino acids of corn protoplasm; none as raw nitrate, precursor of carcinogenic nitrosamine. No pesticides were used; there was no insect damage.
"Most topsoils of the world have been stripped of all but a small quantity of elements. So, it's no surprise chemical-grown corn has substantially less minerals than described in USDA's 1963 Handbook of Nutritional Content of Food. Mineralized corn was substantially higher in minerals than 1963 corn. As elements are used up, a poor food supply in 1963 has turned into a 100% junk food supply in 1978 [with] corresponding increases in disease and medical costs. Disease means enzymes are malfunctioning for lack of elements required."
The role of trace elements in human nutrition and health is a new field, and still controversial. An often cited example is Hunza, a small country in the high Himalayan mountain valleys. The health, strength and longevity of Hunzakuts is legendary. The key is that they irrigate their soils with milky meltwater from the Ultar glacier. The milky color is from rock ground beneath the glacier. Hunzakuts are virtually never sick or develop cancer. Many are active workers at 90; some live to be 140. This is well documented, yet health professionals ignore this and continue the hopeless search for manmade "cures."
THE LINKS BETWEEN TRACE MINERALS AND HEALTH MAY BE UNCERTAIN to science, but for Tom, flavor is the key. He told me, "I insist minerals create flavor. Rockdust fertilized plants have much stronger flavor. Bio-dynamic people know NPK fertilizers produce big plants, but they're missing flavor and enzymes."
Minerals provide electromagnetic charges needed to power enzyme reactions, transport nutrients and provoke our sensation of taste. Food grown in mineralized soil is not only stronger and more compact, but has stronger taste.
Tom continued, "Americans eat too much animal food, and have to reduce that and eat more plant foods. But you won't eat vegetables if they don't taste good. That's why we didn't eat them as kids—boiled, frozen peas taste only a little, but didn't taste that good. It's important to have good quality, tasty vegetables and fruit to get excited about. Our carrot juice this morning was unbelievable. If you want a taste treat, you don't have to get a milkshake."
Another concern is crop resistance to pests and diseases. Tom reports, "Last year was difficult due to dry weather, so I still had problems with disease and insects. We produced crops, but we had to keep trying. I planted a lot in June, but it didn't rain until August, so parsnips and burdock came up in August. It's alright for them, but too late commercially.
"So, last year I can't judge a lot because I couldn't control moisture. When I ran into bugs and disease, I thought about using the powder symptomatically. I was going to try to dust with it, but mine isn't that powdery. Maybe I can sift out the really fine stuff.
"Last year I had problems with root maggot. I think there'll always be some problems; rockdust won't cure all those problems, or eliminate the need for pesticides completely. I don't think you can make soil so balanced insects won't attack weak or diseased plants and finish them off. I can't believe a cabbage butterfly will fly past a cabbage—that's her optimum place to lay eggs—it's what the maggot eats."
TOM TRIED TO INTEREST OTHER FARMERS IN ROCKDUST, with little success, and knows of few trying glacial gravel dust. "Bob Cannard in California grows specialty herbs and vegetables with crushed gravel of the bottom of a river, plus oyster shells and compost. He's a prime supplier to the famous Chez Panisse restaurant. They said his stuff tastes good—it's got a real earthy taste, and is what the woman wanted in her restaurant in the Northeast, many growers don't know why they farm organically, so it's easy for them to miss this potential input to their farm. They're stuck in a manure mentality—throw on some manure, and everything will be fine."
Tom spoke on the rapid expansion of organic markets after Alar and Meryl Streep. "What's happening this year to organic is obviously good. We expect markets to improve, and to be able to sell faster and easier. It's unfortunate that the emphasis is on chemical residues, because it's more than that. It's a sustainable agriculture system. We grow food that is safe to eat and tastes good, but on a practical level, it has a more normal, natural balance of vitamins, minerals and enzymes."
Asked what he'd say if New York's Ag Commissioner was to sit at our table, Tom was skeptical. "I have little faith in government. Basically, I'd tell him to play teacher. There's lots of good information about ecological agriculture—just make it available. They've started to do that. Lots of things can be switched quickly, but farmers aren't aware and are slow to change. Government can do a lot in terms of education.
"Changes are going to come, but by economic choice—by who consumers support with their money. Consumers are the most powerful ally of organic farmers producing quality food. If it tastes good, they like it and feel better after they eat it, then they'll buy it and put money into organic farmers and less in to other hands, and we'll become more powerful. As Mothers and Others for Pesticide Limits said to chain stores: 'Give us organic; we'll pay for it'"
AS I PACKED TO LEAVE, TOM EXCLAIMED, "I ALMOST FORGOT MY STONE TOOLS!" With excitement, he went to the windowsill to retrieve two rocks. One—a nearly perfect sphere of tan, medium grain rock—rested comfortably in my cupped palm. as I twirled it, Tom explained how he found this remarkably geometric rock. The other was a dark gray, flat oval which also fit well in my hand, like a scraping tool.
As I gazed at these rounded relics, I tried to sense their history and learn their tales. Was this a Stone Age tool, left here 5,000 years ago? To my intuition, the rocks and Tom's story had the "right feel" I imagined the tan sphere being used to crush hard kernels of dense, mineralized primitive corn and other seeds. I remembered how for centuries had ground its grain between stones, mixing small amounts of rockdust with the crushed seeds, adding minerals to the grain. And grain was cooked in earthenware pots, adding more minerals to these ancients' diet.
Today, earthenware is replaced with metal, and stone grinders with high speed metal mills spewing super-refined products whose minerals are milled away. It is not just our soils that have lost their precious, essential minerals.
I pondered the significance of the stone tools and Tom's pile of glacial gravel dust. Five thousand years ago is halfway to the end of the last Ice Age. Are we indeed about to witness the onset of a new glacial era, or global warming, or just a period of climatic turmoil? Can we regain some common sense wisdom from those ancestors beyond the pale light at the edge of history? I recalled the words of Masanobu Fukuoka in One Straw Revolution:
"The purpose of agriculture
The Earth Renewal and Restoration Alliance — www.ancientforests.us — www.carbon-negative.us — www.nutrient-dense.info — 2/14/2009