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.

Building Humus For All Crops

This excerpt is brought to you by Book of the Week – offering you a glimpse between the pages and an exclusive discount of a new book each week. Get the Book of the Week email newsletter delivered directly to your in box! This week’s Book of the Week is Humusphere, by Herwig Pommresche.

The term “soil humus content” refers to the totality of all the organic substances present in the soil. It is often expressed in terms of carbon content percentage, as carbon is the basic building block of organic material. But this definition is insufficient as it only reveals the sum of all the carbon atoms contained in the soil. How much of that is valuable compost, living soil biota, liquid manure, or other organic substances is not clarified. A relevant quote comes from M. M. Kononova’s treatise, “The Soil’s Humic Substances – Results and Problems in Humus Research” (1958):

“The history of humus research is rich in incorrect approaches to clarifying important questions, which has led to contradictions and confused ideas about the nature of humic substances, their origins, and the role they play in forming the soil and determining its fertility.”

But if we primarily understand “humus” as referring to the abundance of organic substances present in the soil, we overlook its mineral content. The proportion of minerals has increased in cultivated soils during our era in comparison with past eras in which consistently humid heat promoted the formation of organic soil material over huge swaths of forest for thousands of years.

The ratio between the organic and mineral portions of the material has shifted, to the detriment of the soil.

 Incidentally, this is a particularly strong example of the importance of using the right terms with the right meanings: the word “mineral” is here used correctly to refer to everything from rocks, gravel, and sand to the very finest mechanically ground particles – it has absolutely nothing to do with NPK fertilizers or other salt ions.

One small calculation is sufficient to get an idea of the significance of plant roots in the soil: “The formation of root hairs greatly increases the root’s surface area. Rye (Secale cereale) has about 13,000,000 roots with a surface area of 235 square meters, and 14,000,000,000 root hairs with a surface area of 400 square meters in 1/22 of a cubic meter of soil (…) The surface area of the underground portions is thus 130 times as large as that of the above-ground portions” (Jurzitza 1987, 28).

One single rye plant has the equivalent surface area of an entire garden in direct contact with the soil in which it grows. What this soil is made up of has to be crucially important.

Annie Francé-Harrar (1957) wrote the following about how healthy soil should look for plant roots to be able to optimally carry out their work:

“Ideal soil should have the following composition: 65 percent organic material, 20 percent edaphic organisms, 15 percent mineral substances. (…) But this kind of abundance of organic material exists hardly anywhere on the planet any more, the highest concentrations being in untrodden corners of tropical jungles, but never in our growing soil. But it is possible to restore the organic-inorganic balance in growing soil within a practical timespan through systematically employed humus management.”

These recommended ratios also provide a target to work toward in systematic humus management. But she was already well aware of how difficult it is to put this into practice:

“But this (…) means a radical agricultural revolution, much larger than the one triggered by Liebig in his time” (20).

How does humus form?

Topsoil formation is very much a classic case study in the movement of living material from the waste material of living things into plants, of the descent of living material into Mother Earth.

It’s also a study in the soil, of its many functions, of its conversions and storage until its reappearance in the world of above-ground organisms. The bulk of the soil material first becomes clearly visible as nutrient-forming chlorophyll, but that chlorophyll would never exist without the work of the countless organisms in the soil.

The same species of bacterial symbionts appear in almost all animal and plant organisms, the lactic acid bacteria. In fact, soil probes from all over the world, even if the soil in question is only slightly fertile, always contain large quantities of lactic acid bacteria. The soil contains more of them, and of better varieties, the more fertile it is. This is further evidence that the cycle of living material takes place in the topsoil through the mediation of bacteria.

The remnants of biological processes on the surface, processed by countless species of small creatures, are first processes into precursors by budding fungi species, predominantly yeasts and molds, and then passed along to the bacterial symbionts in the soil. According to the most recent research, these symbionts—lactic acid bacteria in this case—can be directly consumed and digested as food via endocytosis by plant root hairs (Rateaver and Rateaver 1993), and they leave all kinds of organic material behind after they die, especially in the fall.

These particles, as well as the bacteria themselves (i.e., the living material in the soil bacteria), are a prerequisite for the formation of high-quality soil: topsoil that is aerated, loose, water-retaining, capable of biological tillage (Sekera 2012), safe from erosion, and fertile, the result of the functions of the edaphon, as outlined by Henning (2011).

The adhesiveness of the microorganism residues  cements the inorganic mineral substances of rock erosion into soil crumbs. In contrast to the views of agrochemists, it is this alone that deserves the name “humus” in the biological sense: a conglomeration of organic and inorganic material. And this means that it is completely impossible to describe humus as a dead, chemical substance!

Humus formation is a sort of “organic predigestion” for plants; and at the same time, humic soil serves as a pantry of living nutrients during the growing season, when plants can grow only if supplied with sufficient warmth, water, and sunlight.

Otherwise, however, the parallels between animal and plant digestion are unmistakable. In both cases, microorganisms serve as an intermediate station, as “nutrient facilitators,” and in both cases organic or inorganic material can be extracted as needed from the nutrient substrate and used to build cells and tissues.

Edaphon: The “Residents” of the Humusphere

Just as the water has plankton, there is also “the plankton of the soil,” as Raoul H. Francé so singularly described and illustrated the term “edaphon” for us in 1911. The whole fertility of the humusphere depends on this edaphon, and it contains the entire existential basis of our life on this planet. The biosphere carries out its own cycle via its own living beings.

edaphon soil microbe found in humus
Euglena spec. is a single-celled organism containing chlorophyll and a member of the
“plankton of the soil.”

Under the heading “Ein Buch mit vielen Siegeln” (“A Book with Many Seals”) in “Mensch und Umwelt,” J. Filser (1997) writes:

“Microorganisms in the soil can contribute to the nutrition of a plant or strengthen its resistance to pathogenic organisms or the effects of environmental damage. [. . .] They represent a biological potential that promises a wide variety of useful applications in protecting our resources in agriculture and forestry. [. . .] Thus far, only a limited portion of the soil microflora has been cultivated and examined in more detail. We are not even aware of an estimated 90 to 99 percent of soil organisms.”

Edaphon: Plankton of the soil

Just as plankton provides the basic conditions for all further life in the hydrosphere (i.e., in the water) the edaphon provides the basic conditions for all further life in and on the soil.

But it’s possible that even larger quantities of proteins are hidden within it than in plankton! A comparison accentuates this point: the average human biomass in the United States is 18 kilograms per hectare. On the other hand, the average biomass over the same area of insects, earthworms, single-celled organisms, algae, bacteria, and fungi is about 6,500 kilograms. That’s more than 350 times as much!

To break it down more specifically, that’s 150 kilograms of single-celled organisms, 1,000 kilograms of earthworms, 1,000 kilograms of insects, 1,700 kilograms of bacteria, and 2,500 kilograms of fungi (Gaia 1985, 150).

And what’s the breakdown in our gardens? In a 1,000-square-meter garden, 1,000 kilograms of edaphon lives and works in complete silence, without disturbing the neighbors, all year long.

The biomass of the earthworms alone—who represent a part of the edaphon—can be determined by any interested layman by collecting and weighing them. In sandy soil beneath conventional barley, I’ve found 9 grams per square meter of surface area (to the depth of a spade), 49 grams beneath conventional pasture, and 840 grams in my own biologically cultivated garden soil. Per hectare, or 10,000 square meters, that comes out to 90, 490, and up to 8,400 kilograms of living biomass respectively. And that’s just the earthworms?

The ideal for fertile growing soil is (Francé 1911, 1995): 1 kilogram of living biomass or edaphon per square meter of garden or field soil. One kilogram of living cytoplasm per square meter corresponds to 1 metric ton of biomass per 1,000 square meters, or 10 metric tons per hectare. Ten hectares of cultivated field soil thus come with 100 metric tons of living biomass in the form of the edaphon beneath the ground—and that’s without even considering what can be achieved above the ground. That comes out to the weight of one thousand hogs or two hundred cows!

For readers who are farmers: these numbers reveal how much “livestock” you have hidden on your farm, without ever seeing or noticing it. If you converted this quantity into actual livestock, how much would you have to supply them with on your farm in terms of feed, stalling, ventilation, weather protection, and eventual excrement disposal? How about veterinary costs, consultation, and researching?

This is only hard for us to conceptualize because we have neglected it in the models we use to teach and think about agriculture. If you think about these numbers in the context of the new, still unfamiliar “plants can digest protein” model, you quickly recognize the new possibilities that they reveal for our agricultural practices.

Source: Humusphere

About the Author

Herwig Pommeresche was born in Hamburg in 1938 and has lived in Norway since 1974. He received a degree in architecture from the University of Hanover. He has spent many years active as an architect and urban planner in Norway. After finishing his studies in architecture, he became a trained permaculture designer and teacher under the instruction of Professor Declan Kennedy.  Alongside other permaculture experts, he served as an organizer of the third International Permaculture Convergence in Scandinavia in 1993. He later served as a visiting lecturer at the University of Oslo. Today, Herwig Pommeresche is seen as a pillar of the Norwegian permaculture movement. He also serves as an author and a speaker.

Herwig Pommeresche is a holder of the prestigious Francé Medal, awarded in 2010 by the Gesellschaft für Boden, Technik, Qualität (BTQ) e.V. (founded in 1993) in recognition of his contributions to organic methods and ways of thinking and to the preservation and improvement of the humusphere.

Watering Best Practices for Crops

By Charles Walters and Esper K. Chandler

All any farmer really wants is the best uptake of plant nutrients for his or her crops. In order to make sure crops efficiently uptake all they need, crop expert Esper K. Chandler says, “We have to reestablish the humus function of the soil, the basis for natural/organic sustainable farming.” And this means putting water best practices into use.

The drip-irrigation system is a valued key to best watering practices. Not only does it make it possible to feed the plant vital nutrients – especially phosphates – on a cafeteria basis, it enables uptake of existing soil phosphates, thereby doubling the potential.

Drip irrigation for crop water management

Then multiple products of humus, lignosulfates, enzymes, soil inoculants, hormones such as in seaweeds, cytokinins, auxins, and gibberellins bring on another synergistic effect, all of them answering the plant’s call for help.


Non-toxic Management Practices for Weeds

Charles Walters describes important farm management practices concerning soil health and the identification and non-toxic treatment of weeds.

By Charles Walters

For now, it seems appropriate to walk through farm management practices worthy of consideration. How they fit soils in any area and how they dovetail with crop systems projections becomes all important for the grower who wants to minimize the hazards of weeds so that he does not have to depend on the obscene presence of herbicides to control them.

Fall Tillage

Fall tillage has to be considered number one. It is the first thing a farmer should want to do, yet every fall when the crop is harvested, that bad weather always seems to arrive. Often the fall work does not get done. The farmer is too busy harvesting and he can’t get in there and do the tillage.

Moreover, most crops are harvested late because schoolbook technology has given us degenerated soils. We do not convert and use fertilizers, nitrogen and other fertility factors locked up in the soil to properly grow field-ripened crops.

Proper fertility management would see to it that harvest can take place a month earlier and thus permit time for that fall work. That is when compaction could be best removed, when trash could be mulched in. That is also the time when pH modifiers could be applied. That is when lime and other nutrients could be used to influence the quality and character of the soil’s pH, all in time to meld into the soil during fall and over winter.

It is this procedure that would make the soil come alive in spring and get the growing season underway so that crops can germinate a week or ten days earlier.

Fall tillage is an important key to weed management. It is certainly one way to diminish the chances for foxtail and grass type weeds. If fall tillage is used to put soil systems into ridges, those ridges will drain faster in spring. They will warm up a week to ten days earlier. They will have germinating capacity restored earlier and permit planting earlier so that the economic crop can get a head start on weeds.

Once the soil is conditioned, it won’t be necessary to turn the soil so much in spring. Obviously, every time the soil is turned, more weed seeds already in the soil are exposed to sunlight and warmth and other influences that wake them out of dormancy. Soil bedded in the fall, with pH modified so that the structure does not permit crusting when spring rains arrive, will permit rain to soak in faster, bringing air behind it. Such a soil will warm faster and therefore determine the hormone process that will take place. Good water and air entry into the soil will not likely set the stage for foxtail (image below), nut sedge, watergrass and other debilitating influences on the crop.

Foxtail can be avoided with practical weed management
Anhydrous ammonia is almost an insurance policy for its proliferation. Foxtail grows in organic matter soil where there is a surplus of humic acid. Although pH adjustment has been front burner stuff so far, the topic has to surface in any discussion of the foxtail weed problem.

When the cash crop is germinated under these conditions, that is when your little pigweeds and lambsquarters, your broadleaf weeds — which require a good quality available phosphate — hand off their message. They say the phosphate conversion is good and the fertility release system is more than adequate to grow a high-yielding crop.

Such broadleafs are easy to manage. When they germinate and achieve growth of an inch or less, and you tickle the soil before you insert the seed, they are easily killed off. As a consequence, the hormone process gains the upper hand for four to six weeks, a time frame that permits the crops to grow big enough to be cultivated.

Organic Materials in the Soil

Needless to say, the bio-grower has to depend on proper decay of organic materials in the soil. Root residue and crop stover are always present, and these have a direct bearing on how prolific weeds might grow. This means farmers, one and all, must learn how to manage decay of organic matter better.

As we incorporate it into the soil, preside over proper decay conditions by pH management and regulate the water either present or absent, we achieve plenty of air and good humid conditions that will allow organic material to decay properly and in the right direction to provide the steady supply of carbon dioxide necessary for a higher yield.

While adjustments are being made in the soil — soils are sometimes out of equilibrium for years — it is unrealistic to expect the situation will be corrected in a single season or a single month. We can speed the process with the application of properly composted manures. The point here is that there is a difference between quality of various composts, just as there is a difference between predigested manures and manures sheet composted in the soil itself.

Readers of Acres U.S.A. in general, and those who have enjoyed the short book, Pottenger’s Cats, will recall how that great scientist planted dwarf beans in beach sand at Monrovia, California, as part of an experiment. Cats had been raised on that beach sand. Some had been fed evaporated milk, others raw meat, still others meat that had been cooked to achieve near total enzyme-destroying potential and some had been fed on raw milk. Cats fed evaporated milk, cooked meat — dung going into the beach sand — produced a dilapidated, depressed crop of beans. Cats fed whole milk — their dung also going into the beach sand, produced a prolific and extended crop, the dwarf bean variety growing to the top of a six-foot-high cage. The quality of manures used in composting have a direct bearing on the performance of that compost.

Experience has taught all those who wish to see that the kind of compost Fletcher Sims of Canyon, Texas, introduces into the soil has many desirable fungal systems of bacteria and molds. These have the capacity to attack rhizome roots of quackgrass, Johnsongrass, and those type of roots so far under the top of the soil they cannot be reached with physical tools. Compost tells us that we have to set in motion an environment with antagonistic fungi that will attack the rhizomes when they are in a dormant phase as the season begins to close.

In late August and early September, the length of the day shortens. Everything starts to go into fall dormancy. If at that time we can apply a wholesome, properly composted material to the soil and have it working for thirty days before the soil freezes and becomes inactive, a lot of weed cleanup work takes place at that time. Compost will simply digest most of the dormant weed seeds, and in two or three years of this approach seeds are literally vacuumed up, like soil particles on the family room carpet.

The key is timing. When weeds go into dormancy, they are subject to decay. They can be turned into fresh humus, rather than a charge of gunpowder ready to explode. Quackgrass in particular responds to the compost treatment. With calcium-adjusted pH, compost will attack quackgrass roots and rot them out in one season. The same principle operates with deep-rooted rhizomes, Johnsongrass and thistles.

Quackgrass signals soil decay systems are poor
Quackgrass, sometimes called couchgrass. Agropyron repens is shown here (A); its spikelets (B); the ligule (C); and florets (D). Decay systems are at fault when this weed appears.

The simplest way to start a biological weed control program, then, is to adjust the pH. This affects the intake of water and makes it possible to manage water.

In the cornbelt, where rain often comes at the wrong time and where droughts frustrate the best of intentions, this management of water and its capillary return is front burner stuff. pH management directly relates to so many desirable things, there is justification for referring the reader to the several volumes of The Albrecht Papers for background insight.

Soil Management

Each weed has a direct bearing on the track record of the farm. Each reflects back to what the farmer has done correctly or incorrectly over the years. Too often — in this age of super mechanization — we have large fields with soft spots and hard textured soils. The farmer moves across one then over the next area because he feels impelled to farm big fields with big machinery. All the low soil is too wet, and so a pass through sets the stage for wild oats or foxtail in corn, or fall panicum.

Some soils get the wrong treatment simply because they, not the weeds, are in the wrong place. It may be that the eco-farmer will have to redesign the shape of his fields, or plant in strips so that similar types of soils can be planted at the same time, with due regard being given to the need for soils to dry out and warm up and drain properly. It might be better to wait a couple of weeks. A little delay is better than wet soil work which leaves no chance at all for a crop.

As far as weeds as related to insects, the great Professor Phil Callahan has given us a roadmap that cannot be ignored. He called it Tuning In To Nature, and in it he related how the energy in the infrared that is given off by a plant is the signal for insect invasion.

It stands to reason that a plant that is subclinically ill will give off a different wavelength than the one with balanced hormone and enzyme systems. That these signals match up with the signals of lower phylum plants is more than speculation.

While writing An Acres U.S.A. Primer, I often made field observations that supported Callahan. It became obvious that when farmers did certain things in the soil, the crop could endure the presence of insects because they seemed incapable of doing much damage. I didn’t know how the mechanism worked, at least not before the release of Tuning In To Nature.

Weeds are going to tell about the nutritional supply, and they therefore rate as a worthy laboratory for making judgments about the soil’s nutritional system. They can often reveal the nutrients that must be added to the foliage of the growing crop to react with the negative effects of stress. After all, all growing seasons have variable degrees of timing and stress. It is not only necessary to arrive with nutritional support in time, it is mandatory.

The many mansions in the house of weeds all have family histories. They tell more about gene splicing and DNA manipulation than all the journals of genetic engineering put together. And if we pay attention during class, weeds are our greatest teachers. To learn our lessons, we have only to get into the business of watching weeds grow.

Source: Weeds—Control Without Poison 

Tillage Types for Soybeans: Traditional, No-Till and Ridge-Till Methods

By Dr. Harold Willis

The tillage methods you use for soybeans should depend on your climate, soil type, slope, crop rotation, machinery and costs.

Traditional Soybean Tillage

Tillage is done for three reasons: to prepare a seedbed or improve-soil structure, to incorporate organic matter and fertilizers, and to control weeds. There are several commonly used tillage methods. The moldboard plow lifts and turns the soil, inverting the plow layer. This causes drastic disturbance in the soil ecosystem, but can be useful in heavy soils if done in the fall. Winter freezing and thawing may improve soil structure.

Chisel plows fracture the soil rather than turning it. Less energy is needed-to pull the plow, and the soil is disturbed less. Some plant residue is left on the surface, which is helpful for reducing erosion.

Discs cut and loosen soil and incorporate much of the plant residue, but they compact the soil beneath the blades.

Field cultivators and springtooth harrows dig and lift the upper layers of soil and do not compact lower soil. Little residue is incorporated.

Rotary hoes break up clods and crusts and leave a fine-particle layer.

Subsoilers and deep chisels are used to fracture subsoil and break up hard-pans, in an attempt to improve drainage and deep soil structure. Generally the effects are temporary, and without increasing soil humus, hard soil conditions will return.

In general, tillage on humus-poor, heavy soils causes deleterious effects, espe­cially if overdone. Soil structure is destroyed, organic matter disappears and ero­sion increases. Tillage operations should be kept to a minimum if soil is poor.

no-till soybean field
A no-till soybean field in Argentina.

No-till Soybean Farming

The above disadvantages of tillage in poor soils have led to the development and promotion of various reduced- and no-till systems. By using special planters that can operate in surface crop residue and by using high levels of herbicide for weed control, crops can be grown fairly successfully (except in northern climates on poorly drained clay soils).

While it is true that reduced-tillage systems do reduce erosion and save fuel, the requirements for high amounts of fertilizer and pesticides and the long-term tendency for deep soil to become depleted in oxygen and toxic are disadvantages. Soil-living pests and diseases often increase, and springtime soil temperatures may be cold.

All of these disadvantages of no-till could be eliminated and most of the advantages obtained if an adequate level of humus (up to 10 to 12%) is main­tained in the soil and if the use of materials toxic to soil organisms is reduced or eliminated (pesticides, some herbicides, high-salt and chlorine-containing fertilizers, over-use of raw manure). Humus and soil life create loose, non-crusting soil structure and break up hard subsoil and hardpans, improving drainage. Erosion is greatly reduced because humus holds soil particles in small clumps (aggregates).

Ridge Planting

A fairly new tillage method that works well in some cases for corn and soybeans is called ridge planting or ridge-till. Rows must be at least 30 inches apart to allow ridges and valleys to be built up (branching varieties of soybeans must be used). The crop is planted on top of the ridges, with crop residue left in the valleys. Earlier planting is possible because ridge tops warm up soon, and wind erosion is reduced. Ridges catch more snow in winter. Weeds can be cultivated out in the valleys and if necessary, in-row herbicide can be used. Ridges must be built up each year, and machinery must be compatible with the ridge widths.

Still don’t know? Try these studies to learn more about the practical results from no-till and tillage studies:

Rodale Institute study on No-Till

A Yield Comparison from No-Till & Till (Kansas State University)

Benefits of No-Till (Michigan State University)

Soybean Seeding Rates by Tillage (Ohio State University)

No-Till Versus Conventional Soybeans (University of Kentucky)

Source: How to Grow Super Soybeans

Humus: What is it and How is it Formed?

By Erhard Hennig

Humus forms as a result of the complicated interplay between inorganic conversions and organic creatures such as microbes, nematodes, and earthworms. Humus formation is carried out in two steps. First, the organic substances and minerals in the soil disintegrate. Next, totally new combinations of these broken-down products develop. This leads to the initial stages of humus. Humus formation is a biological process. Only 4-12 inches (10-30 centimeters) of humus-containing soil are available in the Earth’s upper crust. This thin layer of earth is all that exists to provide nutrition to all human life. The destiny of mankind depends on these 12 inches!

Humus Formation

Cultivated soils with 2 percent humus content are today considered high-quality farmland. What makes up the remaining 98 percent? Depending on the soil type, organisms contribute about 8 percent, the remains of plants and animals about 5 percent, and air and water around 15 percent.

The other 70 percent of soil mass is thus of purely mineral origin. The mineral part of the soil results from the decomposition and erosion of rock. The dissolution of these components is carried out by organisms called lithobionts, which are the mediators between stone and life. Raoul H. Francé coined the term “lithobiont,” which means “those who live on stone.” Lithobionts are the group of microbes that begin the formation of humus. They produce a life-giving substance from the nonliving mineral. On the basis of this process, living matter, earth, plants, animals, and human beings can begin, step by step, to build.

Healthy soil humus
Humus formation is a biological process.

Only soils with optimal structural tilth have a humus content of 8-10 percent. Untouched soils in primeval forests can at best reach 20 percent. A tropical jungle can’t use up all its organic waste, so it can store humus. All forests accumulate humus, but real humus stores only emerge over the course of millennia. Once upon a time, accumulations of humus known as chernozem (Russian for black earth) could be found in the Ukraine.

Almost all plant communities (except for leguminous plants and untouched forests) use up more humus than they can produce. Strictly speaking, each harvest and each growth of cultivated plants is accompanied by a loss of humus. The lost humus cannot be replaced by any kind of mineral fertilizer. Both deciduous woods and mixed forests can provide their own humus because they are able to make use of their own discarded leaves. Even in nature, without human influence, humus is only produced in deciduous forests and on undisturbed land.

Humus and Manure

Humus is favorably disposed toward the vegetable rather than the animal metabolism. This is why manure, with its high proportion of animal excrement, cannot support natural humus formation. Manure has to be turned into humus before it can be used for fertilization.

Natural Manure
Manure has to be turned into humus before it can be used for fertilization.

Why is this? The microbes living in the soil are more favorably disposed toward the decomposition of pure cellulose than the disintegration of animal excrement, which leaves the intestines in an anaerobic state. This fact was unfortunately not recognized by earlier generations.

Rather than being subjected to aerobic decomposition, manure was simply buried in the field. When introduced to the soil in this way, rotting anaerobic matter remains as an alien element for quite a long time. The manure is disintegrated by specific rot microbes, whereas the microbes inherent to the soil — living under aerobic conditions — are driven out. The question of whether anaerobic or aerobic microbes predominate, and therefore whether rot or decomposition occurs, is crucial for the health of the plants.

The following example reveals how little humus is produced when manure is used: if a dose of 400 quintals (roughly 88,000 pounds) of stable manure is applied to each hectare of soil (on light soils), after half a year, half of the amount of the manure can be found; after one year, only a fifth; and after two years, practically nothing of the manure is left. The organic matter in the soil is quickly consumed and assimilated; it is then mineralized without the production of humus.

Typical manure cultivation has been practiced in Germany for the last 200 years. If manure cultivation were effective, German soils would be very rich in humus. But this isn’t the case. Manure is only the remains of the substances that served the animal as nutrition. All the highly nutritive proteins, carbohydrates, fats, and so on that were produced by the plant have been taken away from the soil, and what remains is poor in nutrients.

In spite of these shortcomings, the custom of manure spreading is still widely practiced. Here is an example: several years ago a renowned child specialist wanted to find out whether the quality of vegetables grown for babies and young children was influenced by fertilization. How did he go about it? He tested the influence of: a) only manure; and b) manure plus mineral fertilizer. The result: the vegetables fertilized exclusively with manure proved not only inferior, but actually dangerous for human health — many of the children in this group were diagnosed with hypochromic anemia. The report about the influence of stable manure on the quality of vegetables even referred to humus-fertilized soils. Such misinformed ideas about humus are still common. Researchers apparently failed to notice that manure is a rot product that contains poisonous substances like indole, skatole, putrescine, and toxic phenols, and that the quality of manured soil is bound to be toxic.

What is Humus?

The question, “What is humus?” is not easy to answer. A German layman, if asked, would probably check the Brockhaus Encyclopedia for an answer. There he would find the following definition: “Humus, black-brown matter in the topsoil, is produced by the putrefaction of vegetable and animal matter. Humus is rich in carbon and is generally acidic as a result of its humic acid content. It increases the water storage potential of the soil and produces carbonic acid, which disintegrates minerals.”

“Humus, black-brown matter in the topsoil, is produced by the putrefaction of vegetable and animal matter.”

Even though this statement is quite basic, one can glean from it some important functions of humus. We know today that plant remains decompose down to their most basic components and plasma residues. Only after the total disintegration of all substances into the elements carbon, nitrogen, potassium, phosphorus, and magnesium can construction begin on what today is generally called humus.

Researchers have proven that plants can receive the final forms of plasma (matter that is not decomposed to the state of mineralization) up to a certain molecular weight. This plasma is then included in their systems. This brings us back to the cycle of living substances, which we have already mentioned above.

Humus cannot be regarded as a real substance but rather as a process — a formation — built from a multitude of constantly changing factors. In order to define humus, the living substance factor has to be taken into consideration. The law of harmony — that is, the law of balance — reigns over all living things. We know all too well the consequences of a disturbed harmony in the soil, this harmony being the precondition for a normal soil life. One could also say, “Harmony equals balance through well-functioning regulative systems in the soil.”

Humus and soil are subject to the same laws as all other living things. But modern agriculture refuses to work in the same way, and the results of ignoring these laws can be seen in our ailing fields with their depleted soils and damaged structures, and in our disease-prone cultivated plants. Dead soils eventually become barren desert land.

Until recently, humus could not be analyzed using the usual chemical methods. Acids, bases, and salts had to be used for chemical investigations, but those substances destroy life and its functions. Incineration did not reveal anything about the structure or the capillary system of the former humus. Without knowledge of this capillary system, nothing would have been discovered about the organisms, how they related to each other, and the harmony in which they worked.

We can discern one key to determining the value of humus from the relationship between carbon and nitrogen. Highly fertile soils should show a carbon/nitrogen relationship of 10:1. Biological investigations, however, are far more interesting because they refer to the living milieu, and in order to form an idea of the world of little creatures one has to study the symbiosis of the living communities.

The Clay-Humus Complex

Even with the above factors, the definition of humus has not yet been exhausted. In this “primitive tissue,” colloids — the very finest soil particles — play a particularly important role. In humus, different nutrients are bound together with clay minerals through adsorption processes. This association of organic fragments such as humic substances with inorganic particles such as clay minerals is usually called the “clay-humus complex.”

Without minerals, a true humus formation would not be possible. Clay and humus colloids are able, mainly due to their electronegative properties, to take up the bases present in the soil, hold them tight, and absorb them. Clay and humus are thus generally referred to as an adsorption complex.

Humus as the clay-humus complex — in other words, as the living organic matter in the soil — also has a buffering effect. Nutrients are only given to the plant if they are required, so an overdose is impossible. However, plants growing on soils lacking in humus take in more nutrients than are needed for the accumulation of plant matter when mineral fertilization occurs. Because organic fertilization prevents superfluous consumption, it can be seen as an energy-saving measure.

We should bear in mind that humus (which our ancestors referred to as the “Primeval Force” of soil) is not matter according to most recent knowledge, but a biological performance. This performance is typical of Mother Earth, and such performances cannot be found anywhere else.

Editor’s Note: This is an excerpt from Secrets of Fertile Soils: Humus as the Guardian of the Fundamentals of Natural Life, published by Acres U.S.A. For more information, visit

Symptoms of Unhealthy Soil

By Margareth Sekera

Structural deterioration takes place to a greater or lesser degree in almost every field, and its consequences include soil that is too silty or too compacted. To make the steps that take place in this situation clear, the sequence of images in Figure 11 below depict the inflow and draining of the water and the resulting changes sustained by the soil.

The images illustrate the water permeating the soil and the increasing saturation that results. The image in the upper left clearly shows the porous, spongelike structure of crumbled soil. The coarse pores are still filled with air, but the crumbs themselves are already saturated with water. Scattered air bubbles are contained within the interiors of the crumbs.

The image in the upper right shows water flowing out of the saturated crumbs and coating them with a thin film of water. Since the transfer of water from the fine pores into the coarse pores produces volatile changes in its surface tension, this process also causes a physical attack against the soil’s structure. While flowing out, the water tears off pieces of soil from the crumbs, beginning the process of microerosion.

In the image in the lower left, the water saturation has proceeded further. Instead of interconnected air channels, there are now large pockets of air inside of the coarse pores. The fine material that has collected now flows through the soil in the films of water.

unhealthy soils exhibit microerosion
Figure 11. Crumb structure microerosion when moisture penetrates the soil.

The image in the lower right depicts a state of full water saturation is depicted in. Other than some small embedded air bubbles, the entire volume of the cavities is filled with water. In the upper area, the structure has already broken down. Comparing the four images provides a simple demonstration of the destructive effects of water.

Even more blatant structural changes are brought on by the outflow of the water. Air begins to flow into the coarse pores once again. The air bubbles that are embedded in the channels move closer to each other. This takes place via pulsating, fitful movements. It causes some of the channels to widen, while other parts of the cavities fill gradually.

In the remaining channels the water flows in a film-like manner along the sides and carries eroded material along with it. The fitful forward motion of the water-air menisci especially impacts areas where eroded material is stored. The movement of the water in the cavities is not consistent; you can frequently observe water moving along with eroded material on one side while causing the soil to become silty on the other. The effects are no different than when a flowing river carries away material along one of its bends only to deposit it further along its course.

In its final stage, the water is so thoroughly drained that only the walls of the large cavities are still covered with a film and no further water movement is easily perceptible, though we can assume that some is still taking place. The dense compaction of the soil can be clearly seen at this point.

Unfortunately, it isn’t possible to make out the motion of the water and the resultant transfer of the soil material from these photomicrographs. Since the flowing water film transports fine eroded material, the direction of the flow is visible, however it frequently switches, especially when water escapes. It’s common for one part of a channel to be coated with flowing water while the other part is covered by apparently motionless water. The violent movement, especially while water is flowing out, often breaks off whole chunks of soil and washes them away.

It’s not unusual for this process to also cause old channels to fill up and new ones to form. If you can visualize the idea of this happening several times over the course of a growing season, then you’ll understand why the soil can be so compacted at harvest time. As this compaction increases over time, however, the water’s flow rate will become more sluggish, mitigating the microerosive effects.

The less stable the crumb structure, the more extreme these effects will be. The destructive power of the water decreases as the stability of the crumbs increase through biological tillage. In freshly worked or fallow soil, water can attack much more furiously than in soil in which living organisms have formed a solid structure through biological tillage and the formation of a humus lining.

The dangers of erosion

Any slope, even the smallest depression, carries the risk of soil erosion due to downward-flowing water. We differentiate between two different forms of erosion: sheet erosion and furrow erosion. The latter takes place in furrows in the soil, where water collects and carves deep furrows as it flows, making the destructive effect of water obvious to anyone.

Less conspicuous but more common and significant is the damage caused by sheet erosion, in which water washes away fine soil from the surface and deposits it into depressions in the earth. In flat or gently rolling terrain, this causes the formation of the well-known “loam crests,” which always cause problems with working the land and are responsible for erratic crop growth. Sheet erosion is especially perceptible when the sterile subsoil becomes visible. It’s common to find different soil compositions in a small area without ever considering that sneaking sheet erosion is taking place, a constant potential threat to a farmer’s work.

A more in-depth look at the problem tells us the following: the primary cause of erosion is absolutely not the downward-flowing water, but rather the fact that the field is not absorbing the water quickly enough. Friable soil with a structure that hasn’t been broken down by rain and has a gradual transition between the topsoil and the subsoil will certainly absorb rain faster than topsoil that breaks down in the rain and accumulates such a backlog of water that it can only flow away via the surface. The subsoil can absorb water many times more quickly if there’s no layer of compacted topsoil acting as a barrier. This is thus the primary cause of erosion.

It begins with the “microerosion” in the soil, which causes the individual crumbs to lose their water resistance and to dissolve in the rain. “Macroerosion” first sets in when water can no longer be absorbed quickly enough or properly distributed due to structural breakdown. The more fundamental cause of soil erosion is therefore a lack of friability in the soil, and both can be considered maladies of a cultivated field.

Figure 12 below shows a beet plot that has been affected by sheet erosion. The beets are fully exposed and the soil is so crusted that it will have to be plowed over and tilled anew.

Sheet erosion occurs with unhealthy soil
Sugar beets exposed by erosion.

With this in mind it’s possible to take a symptomatic approach to fighting erosion (i.e., to remove the appearance of erosion by minimizing how much water drains off of the slope). Plowing across the slope, making use of grass balks, and building terraces are all strategies that can help as they restrict the flow of water and in doing so help ensure that the fine earth is redeposited.

Instead of these methods of defensive warfare against erosion, however, it seems more promising to attack the root of the issue and to eliminate what’s causing the damage — in other words, to take an offensive approach. This can be accomplished by increasing the stability of the tilled soil and above all by making sure that transfer between the topsoil and the subsoil remains possible so that the field can quickly absorb water.

Due to their heavy rains, Americans must make use of every available method of erosion resistance, fighting the erosion both offensively and defensively. In Europe, a prevention-focused approach is possible, and it seems preferable to not just combat the visible effects of erosion but to eliminate the causes as well. Any regimen of soil care must also encompass this task, and with its help it’s possible to master soil erosion.

Source: Healthy Soils, Sick Soils

Better-Performing Soil Types for Growing Soybeans

By Dr. Harold Willis

Ensuring your soil is ready to grow soybeans is usually an early step when determining the type of crop you want to grow.

The first thing we need to think about before doing any field work is the soil and its fertility, for without good soil it is impossible to grow a good crop. And a good soil will actually give the plants protection from adverse weather—cold, frost, drought, excess water—as well as protection from pests and diseases.

Fortunately, the soybean is a hardy, not-too-particular plant and can do reasonably well in a variety of soils and soil conditions, but to produce high yields of top quality soybeans, you need to get your soil into really good condition.

The ideal soil. Ideal soil for peak soybean production is a loose, well-drained loam. All too many fields these days have tight, crusty soil that becomes waterlogged when it rains. More than likely, such soil is low in humus and

Weeds are not a problem when soybeans are planted in the right soil type.
Weeds are not a problem when soybeans are planted in the right soil type. Courtesy How to Grow Super Soybeans

has an imbalance in mineral nutrients. Probably there are few beneficial soil organisms (certain bacteria, fungi, algae, protozoa, earthworms and others). In short, the soil is “dead.”

The advantages of loose, well-aerated soil with adequate humus and abundant living organisms include the following: (1) Loose, aerated soil allows air to get to roots and nitrogen-fixing root nodules, plus it soaks up rain and lessens erosion, and it discourages many of the worst weeds; (2) Humus and soil organisms provide steady, balanced nutrition to roots, soak up and hold moisture (provide “drought-proofing”), and protect roots from harmful nematodes, insects and disease pathogens; And (3) Organic matter also tends to buffer soil from extremes in pH (acidity and alkalinity).

Modern Agriculture & Diseased Soil

Yet many of today’s agricultural practices tend to degrade soil and produce the tight, crusty, lifeless conditions mentioned ear­lier. The overuse of synthetic salt fertilizers and anhydrous ammonia tends to reduce soil life and humus, leading to hard soil. Some of the herbicides and pesticides also do the same thing. Too much field traffic and heavy machinery compact soil. Even using the wrong kind of lime may in some cases lead to soil degradation.

The pioneer of composting, Sir Albert Howard, calls erosion a soil disease in his book, The Soil and Health, p. 85: “Perhaps the most widespread and most important disease of the soil at the present time is soil erosion . . . ”

He states that the keys to the solution of soil erosion are humus and soil microbes, p. 86: “The fragments of mineral matter derived form the weathering of rocks [soil particles] are combined by means of the specks of glue-like organic matter supplied mostly by the dead bodies of the soil bacteria which live on humus . . .

“Provided, however, that we keep up the bacterial population of the land . . . the supplies of glue for making new compound soil particles [soil aggregates] and for repairing the old ones will be assured.

“It will be seen from this how fundamentally important is the role of humus. It is the humus which feeds the bacterial life, which, so to say, glues the soil together and makes it effective.”

Howard calls soil erosion a “man-made disease” and says that it is “always preceded by infertility” (p. 87). He then places the blame: “Soil erosion is nothing less than the outward and visible sign of the com­plete failure of a farming policy. The root causes of this failure are to be found in ourselves.”

Sick soil does not have to be a casualty. The patient can recover if the principles of eco-agriculture are applied.

Loose, well-aerated soil is extremely important in growing healthy, high-producing crops. In the classic text, Soil Conditions and Plant Growth (by E.J. & E.W. Russell, 8th ed., p. 335), we read:

The soil pores that are not filled with water contain gases . . . the rate of transfer of carbon dioxide from the root zone to the atmosphere and of oxygen from the atmosphere to the root zone is a soil property of fundamental importance to the crop, and in humid soils the rate of oxygen penetration probably limits root growth more often than the rate of carbon dioxide re­moval; the oxygen supply is as important in humid soils as is the water supply in arid.

Low oxygen and high carbon dioxide in the soil’s pores can cause a multitude of problems, ranging from damaged roots to toxins released from harmful soil organisms to loss of soil nitrogen to insect attack to low crop yield and poor quality. More details are given in The Coming Revolution in Agriculture, Chapter 3.

How can soil be kept loose and well-aerated? The best long-term solution is to maintain adequate levels of organic matter and to foster beneficial soil life, including earthworms, whose burrows add greatly to soil aeration (see The Rest of the Story, p. 62).

Organic matter makes soil loose and holds water. It is also a food supply for the beneficial soil organisms. The microscopic soil organ­isms, including bacteria and fungi, also help loosen soil because their by-products, sticky materials called polysaccharides, glue tiny soil par­ticles together to form larger clumps called crumbs or aggregates.

Ways of increasing soil organic matter and improving the soil’s crumb structure include incorporating animal manure (or better, rotted manure or compost) and plowing under a green manure crop. Leaving a surface cover of plant residue also helps by reducing erosion and keeping soil moist (as long as it is not wet, waterlogged soil). The application of lime along with manure or other organic matter hastens the process of soil loosening. Leaving a field fallow with a cover crop of grasses and/or legumes will also greatly improve soil structure and fertility.

Source: How to Grow Super Soybeans

Soil Life

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Learn about the creatures — seen and unseen — that have a role in the health of your soil and therefore the health of crops, livestock, farms, and the world.

Our mascot at Acres U.S.A, the dung beetle is ever-useful, and a very promising sign for those who are integrating livestock or manure with their soil development program.
Earthworms literally do the dirty work by helping break down organic matter into the vital nutrients your plants and crops need.
Fungi play a large role in soil health. The different varieties, and their roots, act to make the soil what it is. Learn to identify and care for the fungi in your soil – and it’s so important to do so.