The Dirt on Food: Soil Quality Determines the Nutritional Content of Our Food

Dean Goodale
Dean Goodale (Photo by Lin Mullenneaux)

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

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

I’ve known Dean since the early ‘80s, when we were both students at MIU. I knew that he was running an organic greenhouse, but that was about it. Now, I consider myself a healthy eater, and in Fairfield it’s fairly hard to avoid being exposed to the latest health knowledge. Which is why I was so surprised by what I learned from Dean.

“People eating organic food assume it’s the most nutritious food,” he said. “Organic food can be some of the most nutritious food, 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 of humor, to explain the science behind this statement in a way that even I, a devout non-scientist, could understand. I got an earful—but what he was saying made so much sense. Periodically he’d ask me, “Are you sure you really want to hear all this?” and I’d reassure him that I did.

Soil Makes the Crops

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

It turns out Dean has been involved in the food business on and off his whole life. He grew up near Watsonville, California, where the family business sold food processing machinery; in the mid-80s he worked for a cut-flower grower, for whom he built his first greenhouse; in the mid-90s he built his own greenhouse, off Kelp Avenue north of Fairfield, which eventually supplied fresh produce to his and his wife’s restaurant, The Crepe Escape. Then in 2002 he was recruited for an agricultural project developing organic greenhouses.

Construction of the Maharishi Vedic City Organic Farm greenhouse at its current location on 140th St. began 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 Fairfield restaurants, and several Iowa colleges and universities.

As he talked, Dean explained that the origin of much of what he was sharing was William Albrecht, a soils professor at the University of Missouri School of Agriculture until he passed away in 1974. Albrecht developed a sustainable model of farming using natural inputs by traveling the world looking at all the different soils. He found that the best yields 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, biodynamic farming, and soil fertility as well as Maharishi Vedic agricultural technologies. He is now being called on to speak to groups like the Iowa Fruit and Vegetable Growers Association to share his knowledge of organic greenhouses.

In conventional farming today, Dean explained, most farmers look primarily at N, P, K (nitrogen, phosphorus, potassium) and lime, and neglect important nutrients such as sulfur, manganese, zinc, and copper, some of which work as catalysts for complex metabolic processes in plants that create, for example, long-chain amino acids.

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

Soils Missing Calcium

According to Dean, soil in our area of Iowa is typically very high in magnesium and often too low in calcium. “You want about a 7 to 1 ratio of calcium to magnesium,” he said. “This is an important ratio—Albrecht says the other nutrients come into the plant on the back of calcium, so if the soil is deficient in calcium, the plant will be nutritionally deficient in everything. For some soils in 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 common way for farmers to evaluate the health of the soil, they may get a proper pH reading—because magnesium raises pH just as effectively as calcium—and not fertilize to adjust for the calcium deficiency. As a result, the produce that ends up on our tables is deficient in calcium and other nutrients.

Food is Better Than Pills

Another very striking example he gave of how soil health and human health are related: “There’s a relationship between strokes and selenium deficiency, and the answer is, of course, take selenium pills. But our body is more complex than that. You take a pill, and most of it doesn’t get absorbed.

“Guess what is one of the micronutrients almost completely deficient in the soil through the U.S.—selenium. Imagine that. Why can’t we see the connection? Why is it so hard for the USDA to say, ‘Look, why don’t we implement a program to remineralize the soil with selenium?’ But that’s the thinking that’s not being done.

“There’s nothing like getting these nutritional elements through the food supply. If it’s processed through a plant and the nutrients are available from the food you are eating, you get a completely different effect than taking supplements. They’re in an enzymatic package that works symbiotically with your digestive system to process this stuff and get it into your body.”

Part of the problem, he said, is that “There’s not been a lot of attention on the nutrient density of our food. All the emphasis is being up on growing large, bulky commodities. If you can have the most bushels of corn, the most bushels of beans, that’s what all the breeding has gone into. But bushels of what? Food-like substance. A lot of what is being grown is getting further and further away from what food should be.”

By not taking care of the fundamentals of soil health, our food has become less nutritious. “If you look at what the USDA listed as the nutritional content of a cucumber in 2000, it’s not the same thing they listed for the nutritional content of a cucumber in the 1960s. There was a lot more nutritional content in the 1960s cucumber. Why? Because the soil was in better shape—more micronutrients and minerals in the soil. A lot of that has been mined out now. We’re using more chemicals, we’re using more super-processed fertilizers that are devoid of the broad spectrum of soil minerals, and we have less healthy base soils to start with. If you go back to the 1930s, you’ll get a whole different set of numbers for the nutritional content of a cucumber.

“You can look at some of the best organic growers, and the nutritional content of their crops will be back in the range of—or sometimes better than—those 1930s readings. 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.”

And not just the soil, but also the quality of fertilizers or supplements that are added. “For example, you have an organic farmer who uses cow manure—great, but he could have such high excesses of potassium or phosphorus that he could be tying up critical elements, macro and micro, creating such imbalances in the plant that they’re not fit for human consumption.

“A lot of people have a vested interest in having you believe that your food supply is safe and nutritious. The USDA wants you to believe that there are no nutritional differences in a crop grown from one farm to another. Not true. It’s fiction.”

Dean told me that the first year his farm grew cucumbers, someone from Genetic ID, a Fairfield food DNA-testing company, bought some of his cucumbers off the shelf at a local store and, without his knowledge, had them sent to a lab for testing. “Compared to the USDA standard cucumber, our cucumber had 3 times the vitamin A, 3 times the vitamin C, 1.45 times the calcium, and six times the iron, to name a few, of what the USDA says is in a cucumber.”

Testing with a Refractometer

Dean also introduced me to the concept of Brix level, which some believe give you a reading of a plant’s nutritional quality. The reading is taken with a refractometer, a simple, hand-held instrument that squeezes the leaf or fruit of a plant and refracts light through the juice in a way that gives you a reading of mineral density and sugar content of the liquid.

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

The Produce Test

Listening to Dean, I decided to use the refractometer to compare various produce—organic vs. non-organic, local vs. non-local, freshly picked vs. not. With Dean’s help and a couple of bags of store-bought produce, I did a very non-scientific version of the experiment.

Sample results validated Dean’s point that organic is not necessarily better than non-organic: we found organic lettuce with a Brix reading double of non-organic lettuce, and non-organic Roma tomatoes with a slightly higher reading than organic ones. Freshly picked lettuce from Dean’s farm had a reading more than two times the store-bought organic lettuce, and his peppers had a reading 80 percent higher than store-bought non-organic peppers (we had no store-bought organic peppers).

But he told me you don’t necessarily need a refractometer to judge the nutritional quality of what you eat: “If you’re eating an apple, the sweeter it is, the more minerally dense it is generally. If you bite an apple and it has no flavor, it’s probably not very nutritious. Flavor is a natural way through your taste buds of letting you know how nutritious something is.”

One of the reasons that it’s not just a simple matter of switching from conventional to organic farming is the current state of the soil. “When they cleared this land of the prairies, you had very high levels of organic matter in the soil—5 or 6 percent, as high as 8 percent in places, amazing amounts of organic matter. We’ve been chipping away at that.”

We often hear about having lost half the topsoil through intensive farming, but Dean offered an another explanation for this related to soil biology.

“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 than that. Carbon is a key element of the organic matter in soil—it can 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 enormous amount of water retention. If you have a downpour of 4 inches of rain in one hour, you might be able to hold that if you have 5 to 6 percent organic matter in your soil. It might not even run off. If [the carbon level] drops by 50 percent, the soil won’t have that absorption ability and can get carried away.

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

Killing Soil Organisms

Of course, a key cause of the degradation of soil health has been conventional farming’s reliance on biocides—pesticides, herbicides, fungicides, and chemical fertilizers that by definition kill different forms of living organisms.

“If you spray an herbicide on the crop, it’s killing the weeds, and it’s killing soil biology. If you spray a pesticide, it’s killing the pest, but it’s killing soil biology. If you are using anhydrous ammonia, you’re pumping nitrogen into the soil but you’re killing soil biology.

“For example, the soil has bacteria that can take N2 [nitrogen] in the atmosphere into the soil and process it in such a way that makes it plant available. Ironically, if you’re putting on anhydrous ammonia as your nitrogen source, you’re killing these naturally occurring nitrogen-fixing bacteria.

“Almost everything farmers are doing is biocidal. It doesn’t make sense. When you start zapping the soil like that all the time, you alter the biological balance and the biological profile of the soil. By destroying the biological profile, you’re left with nothing but soil diseases, bacterial and fungal diseases, and their antagonists are not living, so there’s nothing left in the soil to counter them.

“And every year you need to put on more and more chemicals. What is that doing to the soil? Who cares, as long as you’re getting your tons. It’s nutritionally vacant. Who cares? Just keep the wheels turning, everyone’s got a full belly. We’re nutritionally starved, we’re poisoning the environment, depleting our top soil, creating new illnesses, but who cares—the grain bin is topped off.

“The more people are dependent on these specialized fertilizers and chemicals, the more the economic model is based on buying from multinational corporations that are located out of the state. All the money’s getting sucked out of Iowa, sucked out of our rural communities, and going to these multinational corporations. If we got back to a more sustainable approach, we’d be using more and more inputs that are available locally, and a lot more of the money generated by agricultural activity would stay in the community.”

I asked him what’s going to happen if we don’t change things. “We’re going to have to add more and more pesticides, more and more herbicides. We’re going to get sicker and sicker, there will be more and more disease, more cancer. What’s going to happen is what’s happening.

“We have to wake up and realize that we’re biological entities, and growing food is a biological process, and should not be dominated by biocidal activity. How much more basic can you get than that? . . .

“What we’re talking about here is the difference between growing crops that make us sick and plants that actually have medicinal, healing qualities.

“I’m realizing what an art it is, what a science it is, to grow food. We should be training Zen masters in growing food. Instead, we’re dumbing down our farmers—because of drops in commodity pricing, they can’t make a living doing farming full time anymore, so they’re up against the wall; all they’ve got time to do is run out and dump the chemicals on and run back to their full-time job. But then again, what they’re producing isn’t really worth any more than they’re getting [based on nutrition levels].”

So what can we do?

“The bottom line is,” says Dean, “We aren’t ever going to understand and achieve human health until we understand and achieve soil health.”

“Know where your food comes from, know who your farmer is. Does your farmer understand the basic principles of soil fertility?

“Be politically active. Understand that farming has a larger impact on the environment than anything else, because it covers most of the country. We’re doing damage to our environment because of farming practices, and it’s entirely unnecessary.

“We should be lobbying for more funds to go to organic farming and less to chemical farming. Organic standards in general call for improving soil fertility; good organic farming is producing yields comparable to the yields of chemically-intensive crops and nutrient yields that are far, far superior.

“When we see farming practices that degrade the soil, we need to take it personally. We stand arrogantly poised at the top of the biotic pyramid, the foundation of which lies in the microbiology of the soil. We neglect and abuse that foundation to our own peril.”