The Dirt on Food, Aug 06 | The Quality of Our Soil Determines the Nutritional Content of Our Food


Dean Goodale manages the greenhouses for Maharishi Vedic City Organic Farms.(Photoby Lin Mullenneaux).

Dean Goodale explains how vegetables grown today lack thenutritional content of vegetables grown 50 years ago because the soil hasbeen badly depleted.

Every so often, I’m presented with a unique new perspective,one that opens a door to reveal some treasure—a door I hadn’teven thought to look behind, maybe hadn’t even noticed.

In April I made plans to drive to Iowa City to hear Noam Chomsky speakon human rights. While Chomsky was inspiring (even through speakersset up on the street outside a packed Englert Theatre), the new perspectivecame from my passenger on the ride up, Dean Goodale.

I’ve known Dean since the early ’80s, when we were bothstudents at MIU. I knew that he was running an organic greenhouse,but that was about it. Now, I consider myself a healthy eater, andin Fairfield it’s fairly hard to avoid being exposed to the latesthealth knowledge. Which is why I was so surprised by what I learnedfrom Dean.

“People eating organic food assume it’s the most nutritiousfood,” he said. “Organic food can be some of the most nutritiousfood, but it can also be some of the least nutritious food on the planet.It all depends on the soil it was grown in.”

He proceeded rapid-fire, with great passion and a biting sense ofhumor, to explain the science behind this statement in a way that evenI, a devout non-scientist, could understand. I got an earful—butwhat he was saying made so much sense. Periodically he’d askme, “Are you sure you really want to hear all this?” andI’d reassure him that I did.

Healthy Soil is Everything

The basic principle Dean presented is that human health is dependentupon the soil and what is produced from the soil. If the soil doesnot have the proper biological and mineral “profile,” thatis, does not contain the correct substances—minerals, micronutrients,bacteria—and the correct balance of these substances, the soilwill not be healthy, the plants grown in that soil won’t fulfilltheir potential in terms of nutrition, yield, etc., and humans andanimals will not be well nourished.

It turns out Dean has been involved in the food business on and offhis whole life. He grew up near Watsonville, California, where thefamily business sold food processing machinery; in the mid-80s he workedfor a cut-flower grower, for whom he built his first greenhouse; inthe mid-90s he built his own greenhouse, which eventually suppliedfresh produce to his and his wife’s restaurant, The Crepe Escape.Then in 2002 he was recruited for an agricultural project developingorganic greenhouses.

Construction of the MaharishiVedic City Organic Farms greenhousebegan in the fall of 2003, and the first crop was sold in June 2004.Customers include Whole Foods, Chicago distributor Goodness Greenness,New Pioneer Co-op, Everybody’s, Hy-vee, 20 Iowa City and Fairfieldrestaurants, and several Iowa colleges and universities.

As he talked, Dean explained that the origin of much of what he wassharing was William Albrecht, a soils professor at the University ofMissouri School of Agriculture until he passed away in 1974. Albrechtdeveloped a sustainable model of farming using natural inputs by travelingthe world looking at all the different soils. He found that the bestyields came from certain ratios in the soil.

For the past ten years Dean has immersed himself in this approach,reading and taking workshops on soil biology, compost making, biodynamicfarming, and soil fertility. He is now being called on to speak togroups like the Iowa Fruit and Vegetable Growers Association to sharehis knowledge of organic greenhouses.

In conventional farming today, Dean explained, most farmers look primarilyat N, P, K (nitrogen, phosphorus, potassium) and lime, and neglectimportant nutrients such as sulfur, manganese, zinc, and copper, someof which work as catalysts for complex metabolic processes in plantsthat create, for example, long-chain amino acids.

Albrecht’s program, on the other hand, starts by creating anideal, balanced base soil before you even start to think about plantinganything; you’ll still fertilize for the specific crop, but you’llneed a lot less of almost everything.

Local Soil Deficiencies

According to Dean, soil in our area of Iowa is typically very highin magnesium and often too low in calcium. “You want about a7 to 1 ratio of calcium to magnesium,” he said. “This isan important ratio—Albrecht says the other nutrients come intothe plant on the back of calcium, so if the soil is deficient in calcium,the plant will be nutritionally deficient in everything. For some soilsin this area, the ratio is more like 3 to 1, or worse.”

A high-magnesium soil with a 3 to 1 ratio will be deficient in calcium.But if a farmer is adding calcium to the soil only to raise pH, a commonway for farmers to evaluate the health of the soil, they may get aproper pH reading—because magnesium raises pH just as effectivelyas calcium—and not fertilize to adjust for the calcium deficiency.As a result, the produce that ends up on our tables is deficient incalcium and other nutrients.

Another very striking example of how soil health and human health arerelated: “There’s a relationship between strokes and seleniumdeficiency, and the answer is, of course, take selenium pills. Butour body is more complex than that. You take a pill, and most of itdoesn’t get absorbed.

According to Dean, one of the micronutrients that is almost completelydeficient in soil throughout the U.S. is selenium. “Imagine that,” saidDean, ironically, “Why can’t we see the connection? Whyis it so hard for the USDA to say, ‘Look, why don’t weimplement a program to remineralize the soil with selenium?’ Butthat’s the thinking that’s not being done.”

Quantity Reigns Over Quality

Dean went on to emphasize the value of obtaining nutrients like seleniumthrough fresh produce, rather than supplements. Unfortunately, he says,nutrient density in produce isn’t always top on the prioritylist of today’s farmers, thanks to corporate agribusiness.

“All the emphasis is on growing large, bulky commodities. Ifyou can have the most bushels of corn, the most bushels of beans, that’swhat all the breeding has gone into. But bushels of what? Food-likesubstance. A lot of what is being grown is getting further and furtheraway from what food should be,” he said.

Dean explained that by not taking care of the fundamentals of soilhealth, our food supply has become less nutritious. “If you lookat what the USDA listed as the nutritional content of a cucumber in2000,” says Dean, “it’s not the same thing they listedfor the nutritional content of a cucumber in the 1960s. There was alot more nutritional content in the 1960s cucumber. Why? Because thesoil was in better shape—more micronutrients and minerals inthe soil.”

Highly processed chemical fertilizers and pesticides are largely toblame for the poor base soil quality in the U.S. today. And many well-intentioningorganic farmers might be surprised at how nutritionally deficient theirproduce is as a resut.

“You can look at some of the best organic growers, and the nutritionalcontent of their crops will be back in the range of—or sometimesbetter than—those 1930s readings,” says Dean. “Again,you could check some organic farmers and you will see low numbers.It really depends on the quality of the soil it’s grown in.”

Fertilizers or supplements that are added have their impact as well. “Forexample,” says Dean, “you have an organic farmer who usescow manure—great. But he could have such high excesses of potassiumor phosphorus that he could be tying up critical elements, macro andmicro, creating such imbalances in the plant that they’re notfit for human consumption.”

What does the USDA think about all of this? Fine by them, accordingto Dean. “A lot of people have a vested interest in having youbelieve that your food supply is safe and nutritious. The USDA wantsyou to believe that there are no nutritional differences in a cropgrown from one farm to another. Not true. It’s fiction,” hesaid.

Gauging Nutritional Content

These days, not all vegetables are created equal. Dean recounts howthe first year his farm grew cucumbers, someone from Genetic ID, aFairfield food DNA-testing company, bought some of his cukes off theshelf at a local store and, without his knowledge, had them sent toa lab for testing. “Compared to the USDA standard cucumber, ourcucumber had 3 times the vitamin A, 3 times the vitamin C, 1.45 timesthe calcium, and six times the iron, to name a few, of what the USDAsays is in a cucumber.”

So how might a consumer gauge the nutrient levels of her bag of produce?She could get herself a refractometer and measure the plants’ Brixlevel, like Dean does. The refractometer is a simple, hand-held instrumentthat squeezes the leaf or fruit of a plant and refracts light throughthe juice in a way that gives a reading of mineral density and sugarcontent of the liquid. Proponents of the tool believe it offers a readingof any plant’s nutritional quality.

“It’s a very controversial instrument,” Dean said, “becauseit’s a simple way to test if you’re growing high-qualityfood or garbage. If you start getting Brix readings above a certainlevel, for most crops you start getting pest and disease immunity.”

Putting Produce to the Test

I have to admit, my curiosity was piqued. After listening to Dean,I decided to use the refractometer to compare various produce—organicvs. non-organic, local vs. non-local, freshly picked vs. not. Withhis help and a couple of bags of store-bought produce, I did a verynon-scientific version of the experiment.

Our sample results validated Dean’s point that organic is notnecessarily better than non-organic: we found organic lettuce witha Brix reading double of non-organic lettuce, and non-organic Romatomatoes with a slightly higher reading than organic ones. Freshlypicked lettuce from Dean’s farm had a reading more than two timesthe store-bought organic lettuce, and his peppers had a reading 80percent higher than store-bought non-organic peppers.

And when all else fails, there’s always the good old fashionedtaste test. “If you’re eating an apple, the sweeter itis, the more minerally dense it is generally,” says Dean. “Ifyou bite an apple and it has no flavor, it’s probably not verynutritious. Flavor is a natural way through your taste buds of lettingyou know how nutritious something is.”

The Loss of Organic Matter

One of the reasons it’s not just a simple matter of switchingfrom conventional to organic farming is the current state of the soil. “Whenthey cleared this land of the prairies, you had very high levels oforganic matter in the soil—5 or 6 percent, as high as 8 percentin places, amazing amounts of organic matter. We’ve been chippingaway at that,” explains Dean.

We often hear about having lost half the topsoil through intensivefarming, but Dean offers another explanation.

“People say, you plow the land, it’s exposed to the elements,it rains and it washes away, but there’s a lot more to it thanthat. Carbon is a key element of the organic matter in soil—itcan hold 4 to 1 water, so if you’re losing a percentage of this,say 50 percent of your carbon in the soil, you’re losing an enormousamount of water retention. If you have a downpour of 4 inches of rainin one hour, you might be able to hold that if you have 5 to 6 percentorganic matter in your soil. It might not even run off. If [the carbonlevel] drops by 50 percent, the soil won’t have that absorptionability and can get carried away.

“So the more the organic matter decreases, the more soil getscarried away when it rains, and the more that gets carried away, themore organic matter you’re losing. It’s an acceleratingvicious cycle.”

Soil Biocide

Of course, a key cause of the degradation of soil health has beenconventional farming’s reliance on biocides—pesticides,herbicides, fungicides, and chemical fertilizers.

“If you spray an herbicide on the crop, it’s killing theweeds, and it’s killing soil biology. If you are using anhydrousammonia, you’re pumping nitrogen into the soil but you’rekilling soil biology. When you start zapping the soil like that allthe time, you alter the biological balance and the biological profileof the soil.

“And every year you need to put on more and more chemicals. Whatis that doing to the soil? Who cares, as long as you’re gettingyour tons. We’re nutritionally starved, we’re poisoningthe environment, depleting our topsoil, creating new illnesses, butwho cares—the grain bin is topped off.”

Unfortunately, says Dean, the more we are dependent on specializedfertilizers and chemicals, the more the economic model is based onbuying from multinational corporations located out of state.

“All the money’s getting sucked out of Iowa, sucked outof our rural communities, and going to these multinational corporations.If we got back to a more sustainable approach, we’d be usingmore inputs that are available locally, and a lot more money generatedby agricultural activity would stay in the community,” he said.

If things don’t change, our agricultural and nutritional futurelooks bleak, says Dean. “We’re going to have to add moreand more pesticides, more and more herbicides. We’re going toget sicker and sicker, there will be more and more disease, more cancer.What’s going to happen is what is happening.”

But there is hope, Dean insists. “We have to wake up and realizethat we’re biological entities, and growing food should not bedominated by biocidal activity.

“What we’re talking about here is the difference betweengrowing crops that make us sick and plants that actually have medicinal,healing qualities.” Growing nutritious produce is an art form,says Dean, and farmers should be encouraged to go for quality, notjust the bottom dollar.

“Instead,” he says, “we’re dumbing down ourfarmers. Because of drops in commodity pricing, they can’t makea living doing farming full time anymore, so they’re up againstthe wall. All they’ve got time to do is run out and dump thechemicals on and run back to their full-time jobs. But then again,what they’re producing isn’t really worth any more thanthey’re getting [based on nutrition levels].”

So What Can We Do?

“Know where your food comes from,” he says, “Knowwho your farmer is. Does your farmer understand the basic principlesof soil fertility? Be politically active. Understand that farming hasa larger impact on the environment than anything else, because it coversmost of the country.”

Dean advocates lobbying for more funds for organic farming. He alsorecommends farmers take measures to improve soil fertility, which canend up producing “yields comparable to the yields of chemicallyintensive crops” but with “nutrient yields that are far,far superior.”

And last, but certainly not least: “When we see farming practicesthat degrade the soil, we need to take it personally,” says Dean. “Westand arrogantly poised at the top of the biotic pyramid, the foundationof which lies in the microbiology of the soil. We neglect and abusethat foundation to our own peril.”

Dean Goodale will be presentinga free workshop on Backyard Gardening at Revelations, on Saturday,August 19, 2006, at Revelations in Fairfield, Iowa.