Home » Grow Crops » Quest for Quality: Growing Nutrient-Dense Crops

Quest for Quality: Growing Nutrient-Dense Crops

By Leigh Glenn

For Central Virginia farmers Dan Gagnon and Susan Hill, the best proof that they’re doing things right with their soil to produce nutrient-dense crops comes from the mouths of babes and customers facing health challenges.

Gagnon and his wife, Janet Aardema, operate Broadfork Farm in Chesterfield, Virginia. Gagnon likes to observe how children interact with food. His youngest son Beckett, 3, last winter used organic store-bought carrots to dip into salad dressing while Gagnon’s mom was looking after him. But he would not eat the carrots.

When she dropped him off, Gagnon had just dug some overwintered carrots. Despite a bit of dirt clinging to them, Beckett gobbled them up. “The feedback from customers that we continue to get has been very encouraging,” said Gagnon. “Also, a child’s palate is a great indicator of the quality of your produce.”

Hill, who grew up outside Helena, Montana — where, she says, if they didn’t grow it, they didn’t eat — cooks for a woman who has multiple sclerosis; another customer has cancer and another, Lyme disease.

Farmer and soil
Dan Gagnon discusses soil structure at Broadfork Farm in Chesterfield, Virginia.

“Now, people tell me they feel better when they eat my vegetables,” said Hill, who grows in four high tunnels year-round and in raised beds in Louisa, about a half-hour east of Charlottesville. They should feel better, she says, “because they’re getting nutrients they would not get anywhere else.” And that’s what excites her the most about adopting a nutrient-based, quality-focused approach to soil vitality.

At both Broadfork and Hill Farm, the quest for quality is the common denominator. That overarching goal holds promise for reversing a variety of problems that originate with agriculture, from ecosystem degradation to low or no profitability.

A workshop led by farmer and Bionutrient Food Association (BFA) Executive Director Dan Kittredge catalyzed a change in approach for both Gagnon and Hill. BFA is a membership-based, nonprofit educational and research-oriented organization based in Massachusetts with the mission of increasing quality in the food supply, that is, the flavor, aroma and nutritive value of food.

Through the “Principles of Biological Systems” course, Kittredge connects the dots between soil vitality, plant health and human nutrition while helping growers understand the dynamics of their soil and best practices to increase its vitality as demonstrated by markers such as the soil’s ability to hold nutrients and increased organic matter as well as Brix.

Based on soil tests, growers do this through a variety of methods, including cultural practices — such as proper hydration and soil temperature maintenance, minimal tillage, cover crops and crop rotation — and inputs, which range from rock dusts and sea minerals to compost, inoculants and foliar feeds.

When Nothing Grows Well

Kittredge, who grew up on an organic farm, and whose parents, Julie Rawson and Jack Kittredge, have been running the Northeast Organic Farming Association’s Massachusetts chapter since 1985 (Jack retired in 2015), became interested in biological management when he encountered significant pest and disease pressure and saw how these were the key challenge to his ability to make a living farming.

Organic farm
Dan Gagnon prepares new ground at Broadfork Farm.

He began broadly researching soil and agronomy and got some of his major insights into how to do a better job through the Acres U.S.A. community. His “Principles” workshop is a culmination and distillation of his ongoing learning and practice.

Gagnon and Aardema, who both majored in biology, had been gardening for well over a decade before they decided to get into the vegetable business. After a couple years of gearing up they are entering their eighth season selling produce via CSA, an on-site farm stand and at area physical and virtual farmers’ markets. Their farm’s growing space encompasses 1.5 acres near Aardema’s parents’ property, an area that was farmed in the Civil War era, but then allowed to revert to pines early in the last century. Gagnon and Aardema worked on clearing land, developing the gardens and building infrastructure.

Though they tested through the extension service initially, they did not act on the results. The soil — “I call it a sand pit,” says Janet — is sandy loam, 12 to 18 inches deep, over clay subsoil. Gagnon doesn’t know whether the pines acidified the soil or whether it was acidic already, and the pines took advantage of that. The initial test revealed a pH of 5 and a cation exchange capacity — the soil’s ability to hold nutrients — of 2. “So there was nothing there,” he says, “Nothing for nutrients to hold onto, so that’s the reason I think we saw abysmal failures.” Those failures included tomato plants that never made it to maturity and greens that were puny and ran out of energy.

At the time, the couple were in the Elaine Ingham/Soil Food Web camp and thought compost and compost tea would solve their problems. When that approach failed they sought other ways of managing, including Albrecht and soil-balancing techniques, Steve Solomon’s The Intelligent Gardener and then the BFA and Kittredge’s bionutrient crop production workshop in early 2015.

“There is so much information out there on how to amend one’s soil,” said Gagnon. “It can be very confusing if you explore the different ideological soil perspectives.”

Healthy soil with high CEC at Broadfork Farm.

That’s where Gagnon turned to his liberal arts biology background and decided to start testing in earnest and collecting data so that he could see which amendments were working for which crops. They continued to use compost and compost teas, and based on soil testing, began to balance the major cations — calcium, magnesium, phosphorus and potassium — and then micronutrients. The results: a rising pH level, cation exchange capacity in some places of 10 to 11, decreased disease pressure and predation, higher Brix numbers, better soil electrical conductivity and increased flavor.

“We’re seeing all of that,” he says. Something he learned from John Kempf of Advancing EcoAg and paraphrased speaks to this: “When we shoot for quality, yield and flavor — all of those get tagged along. When you just shoot for yield, you’re not necessarily going to get quality and flavor. If your goal is quality, you will get disease resistance, quality and yield.”

The 2017 growing season marked the first in which Gagnon and Aardema eased back on amending the soil for the longer-running beds, and Gagnon says he expects to begin to pay greater attention to nuanced practices, such as how to shift bacterial — or fungal-oriented soil populations depending on what kind of vegetable they’re growing — more bacterial for brassicas, say, and less disturbance and greater fungal populations for tomatoes and other nightshade-family plants.

Hill Farm

About an hour northwest of Broadfork Farm, in Louisa, Susan Hill gets that same kind of feedback children provide Aardema and Gagnon, only it’s coming from adults, such as  the woman for whom she cooks as well as members of her year-round CSA who notice a difference. Their Chesnok Red garlic was so large that she said some outlets she provides it to were not inclined to take it because people think it’s elephant garlic.

Hill and her husband, Scott, found their land in 1999 and he agreed to build her a high tunnel if she would leave her teaching job and become a grower. Scott helps pick tomatoes and monitors and adjusts the sophisticated watering system, and Susan does everything else.

Susan Hill grows large Chesnok Red garlic at Hill Farm in Louisa, Virginia.

Hill says she got a lot out of Kittredge’s workshop, but didn’t apply everything all at once. She keeps careful records and likes to take a slow approach to see what works best where and with which crops. Last year marked her fourth year of “serious nutrient management.”

“When I first got into bionutrient growing, I got Azomite and I did a bed with Azomite — same plants, same original soil — and one without. I just began to experiment. Broad spectrum, I don’t think, is the way to go.” That means if a recipe calls for a quarter-pound of this or that, she won’t necessarily follow it.

“Certain plants need less of something and more of something else. I keep track of all beds, what I put in. If it’s a heavy-feeder brassica, then I’ll go back and add after they’ve been in because of what they feed on.” Growing under stressed conditions to begin with, she adds, there will be issues. The key is figuring out how to supply the plants with what they need so they can adapt and live out their full potential.

To Hill, serious nutrient management means going steady and carefully. She digs holes, puts in the nutrients — which ones depends on which crops she’s planned — dips the roots in compost/worm tea and sets the plants in. It’s an approach tailored to the plants. For example, with tomatoes, she feeds calcium and manganese once a week for the first month the plants are in to help them take up nutrients. As soon as they bloom she stops and switches to SEA-90 — a seawater-based mineral and trace fertilizer.

They don’t need anything else, she says. The proof that it works: In 2017’s challenging drought, the tomatoes were still going in late August. The Hills were the only ones in their neighborhood to have tomatoes, and they had no disease pressure, such as early blight.

Outside the high tunnels, where Hill had rows of tomatoes that had been giving fruit since May, they planned to pull back the high-quality plastic, plant a cover crop, cut it and not till it in and then cover the area again with the plastic. Hill says that allows the cover crop to, in essence, soak in, saves weeding and protects the soil, keeping the moisture in for earthworms when it’s hot. Though the land had been planted in tobacco, she now has 5 to 6 inches of “beautiful soil.”

organic garden
Eggplant going strong in August in a high tunnel at Hill Farm.

As precise as Hill is with her measurements, tests and crop records, she also leaves things that other growers might pull out, such as weeds. She believes everything has a place and everything needs to eat. Evidence of some flea beetles on her still-growing-strong eggplants don’t bother her. She uses pests as prompts to examine what she’s doing and responds, over time, by focusing on nutrients.

She plans to devote more attention this year to brassicas, as the Brix numbers are not as high as she wants and she wants to achieve longer shelf life.

Focus on Nutrient Density

Whether it’s the longevity and lack of pests and disease on her tomatoes, the bounty of her basil — she had been bringing about 40 bunches a week from May to August to Foods of All Nations in Charlottesville — or the size of the Chesnok Red garlic, the bounty of Hill’s farm and the quality of her produce point to an interesting question for growers and others: What is the genetic potential of produce?

We don’t know. The situation is much like that of trying to figure out what a forest is by looking at a second- or third-growth forest; there may be some tall trees, but given environmental changes and disturbance, are those trees living up to their full genetic potential?

The search for quality marks a third phase in agriculture, according to nutritionist Barbara O. Schneeman in “Linking Agricultural Production and Human Nutrition,” in the Journal of the Science of Food and Agriculture. The first phase focuses on yield and ensuring an adequate supply of food. The second hones in on efficiency as a way to increase diversity among sources of nutrients. The third includes targeted ways to improve the nutrient density of particular foods as a way to promote health. We are living in the transition to the third.

“As farmers, we’re not paid based on nutritional value,” said Kittredge. “People have been focused on volume and aesthetic, not animal instinct based on what our nose and tongue tell us.”

Dr. Fred Provenza, professor emeritus in the Department of Wildland Resources, Utah State University, agrees. At an Acres U.S.A. Conference workshop, he used the example of strawberry-flavored Gushers to show how our palates have been hijacked: “You’re getting this big blast of energy because of the corn syrup [in the Gushers], but none of the phytochemicals [found in strawberries].”

“Conventionally, we have made a division between palatability — what a body likes to eat — and nutritional needs — what a body needs to thrive — based on our experience of liking or not for the flavors of foods,” he says. “In the process, we assumed we like foods because they taste good and dislike foods because they taste bad. We didn’t consider that foods taste good when they meet the needs of cells and organ systems, including the microbiome, and they taste bad when they don’t. Phytochemically rich combinations of foods satiate because they meet needs, and they can actually cause us to eat less, not more, food.”

Phytochemical richness — which includes a diversity of primary plant compounds (energy, protein, minerals and vitamins) and secondary plant compounds (phenolics, terpenes, alkaloids, etc.) — creates flavor and links palates, human or ruminant, with nutritional needs, says Provenza.

Fortunately for growers and eaters alike, this richness is influenced by what goes on in the soil. Kittredge likens the process to establishing (or re-establishing) “gut flora” for plants. No matter whether the plant is alfalfa or an apple tree, the idea is to feed the bottom of the food chain, by ensuring proper conditions for biological activity — for life to flourish — and that, in turn, will feed the top — that is, what’s above ground. Growers have the ability to assist in the process. Eaters also exert influence through their palates through which growers, and whose practices, they choose to support. It’s the essence of a feedback loop.

Where to Begin Growing Nutrient-Dense Crops?

For anyone interested in adopting a quality-based, nutrient-dense approach, there are many places one could start, but why not begin with seed? Kittredge notes that the majority of growers will not get the best seed available — won’t get the best genetic potential, in other words, as others, including seedsmen themselves, typically have dibs on them. That’s why it’s important to focus on seed size when ordering. Large seed size — measured as fewer seeds per pound — indicates greater vigor and germination speed. As one example, Kittredge found the range for Bolero carrots to be 800,000 to 100,000 seeds per pound.

Starting with the best seed makes things easier, but then growers can influence subsequent generations through how they support the soil and the plants. In his workshop, Kittredge shares a story about arugula. He called around to three different seed companies to find out, not germination rates, but rather how many seeds per pound they were offering. He bought 4 pounds of arugula with the greatest seed size. He planted 3 pounds and used his usual practices of biomanagement, picked and assessed the plants and let them go to seed.

He harvested the seed and then planted that along with the remaining pound of arugula seed later in the same season. With the saved seed, he saw “a dramatic increase in germination speed, vigor and functional yield” in terms of leaf size and thickness, plus pest resistance, a decrease in purpling and an increase in cold tolerance.

After acquiring your seed, inoculate it. Kittredge says that’s where growers get their best bang for the money spent — and if you make your own inoculant, you may not need to spend anything. He recommends ensuring that the seed inoculant is broad spectrum and includes a dozen fungi and a couple dozen bacteria families.

To begin managing the soil for quality, understand what’s going on there. A soil electrical conductivity meter can help you begin to understand the influence of your soil on your plants as well as your cultural practices, such as hydration and temperature maintenance. Is the soil moist enough? Are you keeping it covered well enough, either with cover crops or mulches?

In North America, it’s fairly easy to find the nutrients needed to correct deficiencies, but Kittredge says remineralization is needed worldwide, and the least expensive ways to start remineralizing are through rock dusts — anywhere there’s asphalt, there is usually a local quarry that provides the crushed rock — and sea minerals.

Basalt-based rock dusts don’t cost much per ton; more money will be spent on delivery. The BFA, through its local chapters, has begun to create mineral depots to help in this process, though they are not available everywhere.

Amend Based on Soil Test Results

Get a high-quality, Albrecht-type soil test that checks for macronutrients as well as trace minerals. Kittredge suggests testing at the autumnal equinox and applying any nutrients to counter deficiencies in the fall as, in most places, things are going dormant. Focus on the most nutrient-deficient areas — whether a few acres or a few hundred square feet.

Based on your test results, determine what you need using these calculations:

Ppm (parts per million) multiplied by 2 gives you the lb/acre (pounds per acre) needed. So, for example, if you are looking at sulfur, the target is 75 ppm or 150 lb/acre. Your soil report indicates you’ve got 16 ppm. Multiply the 16 by 2, which shows you have 32 lb/acre. With the target of 150 lb/acre, subtract 32 from 150 (150 – 32 = 118), which gives 118 lb/acre of sulfur needed.

If you take something such as gypsum, you’ll see its sulfur content is 19 percent (19 percent of a 100-lb bag). If you need 118 lb/acre, you divide 118 by .19 (convert the content percentage to a decimal), which gives 621 lb/acre. The gypsum of course also has calcium. So, you can run the same process for calcium and start at 500 lb/acre of gypsum. (For gypsum, says Kittredge, all of the elders he spoken with say to apply no more than 500 lb/acre at any one time.)

Make sure the nutrients are tied to a carbon source, so that they don’t burn plants or soil life. For example, they can be mixed with humates and broadcast-spread — which is what Kittredge does, letting his “livestock” partners, the earthworms and other soil fauna, work them in — or layered within a compost pile, or combined with molasses or sugar and sprayed on.

Kittredge says to think of the soil like you would your gastrointestinal tract. How do you feel after eating a big meal? It’s the same with soil; too much cannot be easily digested, so it’s best to apply some nutrients and test again later to see how things are moving and continue to apply and retest until conditions are optimal. Doing too much can create excesses, which are much more difficult to correct than deficiencies.

As you apply and retest, you’ll also be checking yields and quality. This is where the conductivity meter and refractometer come in. Kittredge suggests testing once a week, about 7 a.m., and spending an hour at that time to check your plants. You are not using just these tools, but making visual and organoleptic inspections to correlate the numbers with plant growth and plant habits. In time, this facilitates a far deeper perception of what’s going on belowground and how it’s affecting what’s above and what adjustments you may need to make.

Closing the Loops with Feedback

In his research with ruminants, Provenza found that health ensues when wild or domestic herbivores forage on landscapes rich in phytonutrients, but not so much when they forage on monoculture pastures. He also found their health really takes a hit when they are in feedlots. The same, he says, is true for humans “who forage in modern food outlets.”

But the links between the impact of soil on plant health (and plant health on soil activity) and the flavors of those plants and how they influence human health are only beginning to be assessed. That’s a challenging process due to the multitude of variables at work. Humans don’t make for good experimental controls because we seldom eat the same thing every day.

Still, eaters and growers can help increase knowledge through two tools BFA supports. One is the Bionutrient Meter, a tool that uses spectroscopy to determine the nutrients and compounds present in a food. Now in the prototype stage, it’s anticipated the tool could become available on next-generation phones. Users would “scan” produce by flashing a light at it to assess the levels and ratios of nutrients and compounds.

Kittredge says findings from the tool will help growers understand how healthy their crops are while in the field and what can be done to increase their vitality before harvest. Eaters could use the tool to choose which items to purchase at the farmers’ market or supermarket.

The core idea is that transparency will help align the supply chain with food quality and that will have a cascade of effects, ranging from sequestering carbon in the soil to reversing and preventing degenerative disease.

Peer-to-Peer Platform

Growers also have an opportunity to help by recording and sharing their own data and observations through FarmOS, an open-source, peer-to-peer platform under development.

“It’s in service for this ideal of global knowledge and local production,” said Dr. Dorn Cox, founding member of the FarmOS community, research director at Wolfe’s Neck Farm in Freeport, Maine, and farmer on his family’s 250-acre diversified Tuckaway Farm in Lee, New Hampshire. A variety of farming operations have been included to help build out the platform — mixed animal, dairies, market gardens and small grains and oil seed.

Cox says it’s a big commitment for farmers, much like implementing Quickbooks. As the project moves forward, things should become easier, such as through voice-activated observations and recordkeeping to minimize the need for farmers to stop to make notes.

Even though FarmOS is in the early stages, Cox has been impressed by how much can be learned from just two soil indicators — moisture and temperature.

“It comes back to those core principles of building soil health and keeping photosynthesis going as much as possible,” said Cox, who has a Ph.D. in natural resources and Earth systems science. “Water is one of the most limiting nutrients in any environment. It’s almost always in surplus or deficit. Soil temperature is really important for biology — just that little mulch is critical to keep soil in a certain temperature range to function biologically.”

Cox had seen all of that before, but had not recognized how sensitive soil bacterial and fungal populations are to temperature.

The effectiveness of practices such as maintaining diverse rotations and not tilling can be somewhat measured through moisture and temperature, he says.

With FarmOS’s common open architecture, farms that are similar will be able to work together and even where they are different, they’ll be able to tailor biological management practices based on what they can glean from other farmers.

A tool like FarmOS, which can confirm what kinds of practices help to build soil, “gives every farmer the chance to be the best farmer they can be,” said Cox. “You can only experiment so much each year, but if you collaborate, you’ve just extended your lifetime. That’s exciting.”

Editor’s Note: This article appeared in the May 2018 issue of Acres U.S.A.

Learn more about the Bionutrient Food Association and Dan Kittredge and Broadfork Farm.