Key to High Yield is Available Minerals in Soil


Herodotus was an ancient Greek historian who lived from 484-425 B.C. He is credited as one who helped compile the Seven Wonders of the Ancient World. The Seven Wonders of the Ancient World were all man-made edifices located around the Mediterranean rim and in Mesopotamia. It appears the compiled list was funded and promoted by the Greek Tourism Board.

In my mind one of the greatest wonders of the world is right below our feet: soil.

• Soil is the Foundation of Society

• Soil is the Foundation of Health

• Soil is a Fascinating World with Much Yet to be Discovered

• Soil is a Teeming Metropolis with Vast Biodiversity

Soil is where life interacts with life and where life interacts with its environment. It is my sincere belief that we have not yet realized the full potential of soil. We are, in fact, still peeping through the keyhole. The best is yet to come. The world has yet to see a fully optimized soil and the tremendous yield and quality it can produce.

Soil is where biology interacts with chemistry and where chemistry interacts with physics, and where physics interacts with biology — all at the same time.

Most soil tests measure soil minerals using chemistry. Let’s take an example using calcium and magnesium. By measuring both the calcium and magnesium, a ratio between the two can be computed. Consider a soil with 1,400 lbs. of calcium and 70 lbs. of magnesium per acre. This soil would have a 20:1 calcium to magnesium ratio (1,400 / 70 = 20). If the magnesium was 700 lbs. per acre it would be a 2:1 ratio.

When these tests are performed using the Original Morgan test the ratios directly relate to soil physics, and soil physics directly relate to biology and the environment for biology. The desired ratio for calcium to magnesium is 7:1. A 20:1 ratio could be a soil with inadequate cohesion. It is too loose and can erode easily. On the other hand, a 2:1 Cal/Mag ratio indicates extremely tight and sticky soil. When this soil gets muddy walk on it at your own risk.

Because the soil is so tightly compacted there is very little room for air. The environment lacks oxygen and is detrimental to soil biology. The extreme tightness is also detrimental to plant roots. It is a struggle just to survive. To make matters worse the extreme level of magnesium dissipates soil nitrogen back into the atmosphere. The economics of growing a crop on this soil does not cash flow — especially with a nitrogen-loving crop.

Let’s recap. The calcium to magnesium levels are tested using chemistry. The ratio between both elements directly relate to physics and consequently impacts biology. In other words, biology, chemistry and physics are all intertwined.

The difficulty we face is that testing is done with chemistry while understanding biology and physics must be inferred from the soil test, i.e. chemistry. The good news is that the right soil test and theory make it much easier to understand biology and physics.

Here is a statement that is both obvious and profound: Biology thrives in the right environment. The implications are that we as farmers, consultants and growers need to create the right environment for biology.

Let me say it more boldly. As stewards of the land and soil, we have a moral imperative to create the right environment for biology. What biology you ask? All biology. From the microbe interacting with plant roots to downstream river biology to the ultimate consumers of the crops we raise. And this imperative leads us right back to soil testing.

By using the diagnostic tool of soil testing we analyze soil chemistry. But what we are really doing is assessing the environment of the biology. By acting on the information given on the soil test we are actively changing the environment for biology.

So, what is soil physically constructed from?

• Structural particles of sand, silt, and clay

• Environmental prerequisites of moisture and air

• Carbon compounds

• Soil biology ranging from bacteria to earthworms

• Plant roots

The goal with soil testing is to assess the environment for biology and then enhance it through the application of soil amendments and specific nutrients. After many years of reading the Original Morgan soil test on thousands of different soils, I observe that soils can be grouped into various patterns. As a consultant my goal is to change the pattern to a pattern that optimally supports roots and biology. Once in while I will see a soil that is already in the optimum pattern, but this is rare. In that case, the goal is to hold the soil in that pattern.

The optimum pattern will support an extensive network of roots and lots of plant carbohydrates feeding to soil microbes. It is also important that plenty of minerals are supplied ready to be digested and made available for plant uptake.

The key to achieving excellent quality crops with very high yield is to have a reserve of predigested minerals ready for plant uptake. These minerals have already gone through microbial digestion. Not only do you need the right quantity you also need the right spectrum. Plants and all biology do best when given full-spectrum nutrition. This means major minerals, secondary minerals, trace minerals and rare earth elements. To get full-spectrum nutrition requires various fertilizers, soil amendments and rock powders. This will be the subject of future articles.

Certain carbon compounds can also be added to soil to enhance the environment. Remember from my previous article that carbon compounds have the potential to hold heat energy. By adding needed minerals and carbon compounds, the pattern of soil changes. At the same time, minerals are removed from the soil primarily through crop removal but also through leaching.

Annual soil testing is a very important time to stop and ask “Where is the soil right now?” Minerals have been added, microbes have been digesting, and plants have been removing nutrients. Productive soil is most always in a state of flux — ever changing.

At this point, it is very important to ask what type of soil testing should be done. I suggest the Original Morgan and will explain why, but first an illustration.

My wife and I have coffee together every morning. I grind the coffee beans fresh and then blend in some grass-fed butter and a refined oil from coconuts to make a frothy cup of morning Java. And we always sprinkle the top with plenty of cinnamon. Since we really like our coffee, I also grind the cinnamon in batches to make our own cinnamon powder. Here is a picture of a recent batch. What starts as a stick of bark is first broken and then ground in a spice grinder. Then it needs to be sifted to get the fine powder. I don’t like to chew whole cinnamon sticks with my coffee nor do I prefer the coarse sifting. The best flavor comes from the fine powder.

Having predigested minerals ready for plants to absorb them is like the difference between a cinnamon stick and a fine cinnamon powder. Photo by Jon Frank

Think of this as the process soil amendments and rock powders must go through. Let’s take calcium in the form of limestone. What starts out as calcium carbonate must be broken down into an available form of calcium for plants to pick up.

As limestone is broken down some becomes available calcium and some is in the soil but not yet available. Most soil tests answer the question: What nutrients are in the soil? This is similar to the cinnamon that comes out of the spice grinder. Some of it is powder and some of it is too coarse to use.

The Original Morgan test was patterned after root exudates and asks the question: What nutrients can plants get? This is similar to the fine cinnamon powder after the sifting. It is not the total in the soil but instead the fraction that is actually plant available after have gone through microbial digestion.

The clarity of knowing what nutrients are available to the plant paints a clear picture of the pattern of the soil.

If both the available and unavailable nutrients are measured together, you cannot tell which is which. Clarity is lost. This is very similar to a radio signal that has too much noise with it. The Original Morgan soil test is, in my opinion, the best test to sift out the noise and thus see the real pattern of the soil. This is why Dr. Carey Reams only promoted this soil test and why it became the premier diagnostic tool in Reams Agriculture.

I close this article with a toast to one of the true wonders of the world: Soil. I hope you get your hands in some this spring.

Jon Frank is the owner of International Ag Labs, based in southern Minnesota. He is a soil consultant with over 20 years of experience in his field. He is the founder of High Brix Gardens, the market garden/backyard garden division of IAL. Jon is fascinated with the correlation between minerally rich soil and nutrient-dense food and its subsequent impact on human health.

This article was previously published in the June 2020 issue of Acres U.S.A. magazine.

Learn More About the HSS Replay!

The live event August 25-26 featured speakers like Klaas Martens, Glen Rabenberg, Mimi Casteel, Nicole Masters, Michael Phillips and more! Register for the replay and get all the educational workshops in the replay. Includes downloadable presentations and special book deals! Learn more about the HSS Replay here!

Healthy Soil Summit 2020

Soil Balancing: Worth Another Look — The Ohio State University Soil Balancing Team

By Matthew Kleinhenz

Farmers make multiple management decisions daily — decisions driven by questions and input. Helpful input can come from many sources, guiding what to choose or avoid. Most university-led research has placed soil balancing on the “avoid” list. Still, it’s practiced by many farmers who report improved soil tilth, better crop yields and quality, and greater ease in managing weeds as the ‘balance’ of their soils improves.

At least one team of university researchers remains curious, wanting another look at soil balancing. Their work is beginning to reveal that farmers and researchers think, talk about, experiment with, and understand soil balancing differently. If those differences could be bridged, what new questions and helpful input might researchers and farmers find by working together?

The Science Behind Soil Balancing: Basic Cation Saturation Ratio

Soils vary in their nutrient content, but also in their ability to hold nutrients. A soil’s ability to hold nutrients is measured by its cation exchange capacity (or CEC). Generally, a soil high in clay content will have a higher CEC, but organic matter also increases CEC. Soils with a high CEC hold more nutrients and thus, can release more than soils low in CEC.

Soil balancing focuses on managing the ratio of specific cations in a soil’s CEC. Based on the theory of Basic Cation Saturation Ratio (or BCSR), soil balancers strive to attain an optimal ratio of the cation nutrients calcium (Ca), magnesium (Mg) and potassium (K), in the soil. Although recommendations have varied by researcher, most call for 65% Ca, 10% Mg, and 5% K.

Soil particle ions
Soil particles contain exchange sites that can hold positively charged ions (e.g., Ca, Mg, and K). Soil balancing calls for specific percentages of these sites to be occupied by these three ions. Thus, at its core, soil balancing is about managing soil chemistry.

Soil balancing concepts were first proposed in the late 1800s by a German scientist, Oscar Loew, and then were built upon by others starting in the mid-1900s. However, the main concepts are commonly associated with William A. Albrecht, a Professor at the University of Missouri during the 1930s-1960s. Albrecht believed crops responded to limestone or gypsum primarily because of increased Ca levels, not changes in soil pH.

A Review of Past Research

The benefits of Ca have been supported by research. Ca helps form bridges between organic and clay surfaces, leading to better soil aggregate stability, while very high Mg levels can reduce pore space and lead to “tighter” soils. Improved soil structure facilitates better drainage, which can mean better seedling establishment, root growth, aeration, and nutrient availability. BCSR theorizes that adding Ca through large inputs of calcium-rich amendments like limestone or gypsum, will improve soil structure. But in controlled experiments, crops performed the same at a variety of Ca:Mg ratios, as long as sufficient supplies of Ca and Mg were available. Past research has also shown good soil structure to exist at a variety of Ca:Mg ratios.

With regard to soil fertility management, land grant universities have historically advocated for determining a sufficient level for each nutrient in the soil. This approach is sometimes called Sufficiency Level of Available Nutrients (SLAN) and differs from BCSR’s focus on Ca:Mg:K ratios. Agricultural researchers have evaluated SLAN-based approaches for decades, but BCSR approaches have been studied and reported on far less.

When comparing the two approaches, researchers have not seen increased yields with BCSR. For many soils, achieving balance requires relatively large inputs of soil amendments to raise Ca to the desired level. A balanced soil is rarely achieved quickly and often requires an investment of time and materials. Based on research to date, that investment is unlikely to be paid back with increased crop yields.

Ohio State University reverse field day participants
Researchers and members of a stakeholder advisory committee gather for a reverse field day to view on-farm research. Stakeholders were invited to view the farm plots, discuss preliminary findings, and comment on the focus and strategy of future research.

With few reproducible scientific studies to back up the positive experiences reported by farmers, soil fertility specialists like The Ohio State University’s Steve Culman are hesitant to include soil balancing in recommendations or classroom lectures.

“I will remain skeptical until I find out otherwise,” he says. “I am going to need very good evidence right now to suggest that spending all that money on material is worth it.”

However, there are limitations in the past research, as noted by a literature review done by Culman and postdoctoral researcher Vijayasatya Chaganti. Initial discussions with leading proponents of balancing revealed a general feeling that past research studies were too short, focused on too narrow a conception of soil balancing, or measured too few of the outcomes organic farmers consider as important.

Looking for New Direction

Despite the lack of support for BSCR in scientific literature, farmers and farm-advisers continue to report improvements in their soils and crops that they attribute to a soil balancing approach. These reports and the limitations of previous research were enough to pique the interest of several researchers at Ohio State.

Lead investigator Doug Doohan, a weed specialist at Ohio State, says he had encountered soil balancing in the ’90s, but had not taken it very seriously. Around 2011, a graduate student research project prompted Doohan to think soil balancing was more wide-spread among organic farmers than he had initially thought. He found colleagues at Ohio State with similar experiences. Vegetable production specialist Matt Kleinhenz also experienced farmers mentioning soil balancing as a way to improve crop quality. Incorporating input from farmer stakeholders affiliated with the university’s organic research program, several researchable questions began to crop up. Many of these questions crossed traditional discipline lines, allowing the Ohio State soil balancing project to include contributors from multiple research areas. Current primary investigators include Doohan and Kleinhenz, plus soil fertility specialist Steve Culman, economist Subbu Kumarappan, and social scientist Doug Jackson-Smith.

Team members were interested in the thought process behind organic farmers’ adherence to soil balancing. Did the farmers’ direct experience and unique vantage point reveal something researchers were missing?

To develop a better picture of practitioner views on balancing, researchers Doug Jackson-Smith and Caroline Brock conducted a series of semi-structured interviews with farmers and consultants. Starting with recommendations from the team’s advisory board and partner farmers, Jackson-Smith and Brock eventually interviewed a cross-section of 33 growers and crop consultants.

“The interview method is a very effective way to get into depth and detail about the nuances of what people do and why they do it,” says Jackson-Smith.

Very little work has been done to document the experiences and practices of the soil balancing community, according to Brock, who is also studying the history of soil balance theory. What exactly were practitioners observing on their farms? How did they carry out soil balancing techniques in real field conditions? How widespread is the practice?

By asking open-ended questions about management practices and decision-making, Brock and Jackson-Smith began to see a “complexity” of ideas out there.

“Farmers and consultants have a broad approach to soil balancing, which includes multiple factors: chemistry, biology, and physics, along with key management practices,” noted Brock.

According to Brock, this broader view included a ‘balanced soil biology,’ which may involve the applications of micro-nutrient blends and microbial formulations thought to facilitate the balancing process and contribute to overall soil health. Farmers either included these additional practices in their definitions of soil balancing or considered them as crucial in making balancing work.

Jackson-Smith said several interviewees actually warned against thinking that “altering your Ca-Mg balance was going to be a magic bullet.” Rather, balancing was “part of a suite of things they were doing.”

Many farmers are even using balancing in conjunction with conventional SLAN fertility programs. Perhaps past research studies that tested these two practices as competing theories have missed the mark. Alternatively, the working definition of soil balancing may have shifted over time and no longer hinge on BCSR alone.

Another important find in the interviews related to the goals of soil balancing. While most research trials on BCSR have focused on increasing crop yields, this was not the most frequently mentioned benefit of balancing during the interviews. Improved soil structure was cited most often. One farmer referred to balancing as a way of “feeding the soil rather than the crop.”

Ohio State’s Soil Balancing team also used a more traditional survey. While interviews are good at finding in-depth information on decision making processes, a survey can collect enough data to reveal characteristics about a larger group of people. In a survey of organic corn growers in the Midwest, respondents were given a definition of soil balancing that focused on BCSR and asked if they were soil balancers by that definition. A little more than half of the 850 respondents indicated they were soil balancers. However, in an open-ended question respondents were asked what management practices they used for soil balancing. Only 20% mentioned BCSR-related concepts, indicating there is more to balancing for many of these growers.

“I think there are two definitions we’re becoming aware of,” summarizes Culman. “One is the more academic take which is really focused on calcium-magnesium ratios. The second is a more holistic approach that nearly every grower or person that we’ve talked to about this thinks, which is certainly more than just Ca:Mg, but more of a whole nutrient profile type.”

Lead project investigator and weed specialist Doug Doohan says this difference of definitions plays into a longstanding issue with research in organic agriculture. While scientists often focus on testing single variables, organic farming is more focused on systems and long-term results. Thinking about systems requires a different approach than most researchers are used to and involves some “stepping outside the comfort zone,” according to Doohan.

Asking New Research Questions

To ensure their research matches more closely with real farmer situations and practices, the research team established a stakeholder committee of growers and consultants very early in the process. This group provides feedback on research approaches and future directions the work might take. By partnering with organic grower associations, the team has also been able to include on-farm research plots, which brings a variety of conditions and soil types into the mix.

According to team researcher and vegetable production specialist Matt Kleinhenz, lengthening the study and evaluating variables other than yield alone were major changes the team planned to implement from day one. The team is also looking at a larger variety of crops, including both agronomic and vegetable production systems.

The ongoing experiments at Ohio State research stations and partner farms are examining a range of variables: yield, but also input costs, crop nutrient content and quality, weed and pest populations, drainage, and other soil health indicators. In addition, they are studying the effectiveness of different Ca-rich amendments next to amendments that simply raise the pH without adding Ca. And field experiments vary from short-term, one growing season studies to five-year studies – hopefully longer.

Moving the Conversation Forward

As data from surveys and field studies are analyzed, new questions are already arising. Does soil type change the effectiveness of balancing? Can soil balancing cause or prevent nutrient interactions and deficiencies? What additional variables should be examined?

The Ohio State team is of course looking to document any significant effects traditional soil balancing has on the physical and biological properties of soils, fields, or crops grown on them. But an equally important goal is to foster a better exchange of ideas between researchers and those in the field. The team seeks to establish a commonly accepted knowledge base on soil balancing that will help move the conversation forward.

So far researchers have found common ground among soil balancers, many of whom are using balancing not as a replacement for recommended methods, as some researchers once thought, but as a supplement, also relying on more agreed-upon techniques such as increasing organic matter and conducting soil tests. In time, the research team hopes their work will result in practical and relevant guidelines for those using or considering soil balancing as part of their management techniques.

Doohan says the team has caught a few glimmers of light in their field research data. He feels confident the group will find theoretical explanations for the observations farmers are reporting.

Meanwhile, the open communications between researchers and growers has been a positive learning experience.

“They’ve learned that we actually are interested in their experiences. And that we are interested in working with them,” says Doohan. “And I think they’ve learned that we respect them; that we respect their knowledge, their experience, as special, unique, and different from ours, and that we can learn from them.”

Ohio State hopes to share additional research findings in future articles. Stay tuned for results of survey and field data so far.

Into the Weeds with Soil Balancing – The Ohio State University Soil Balancing Team

By Matthew Kleinhenz

Maybe you remember learning in school about the scientific method – the way that we humans study the world around us (question, hypothesis, test, data analysis, conclusions, retest, etc.).

According to the scientific method, research begins with curiosity and observation, and progresses to a hypothesis (or educated guess) about how and why the world functions. Farmers, researchers, and other professionals who need real answers, continue the process. They look for evidence to support or refute these educated guesses and they create ways to test their ideas. Depending on the situation, this could be a farmer talking to his neighbors for advice, or taking close notes on a new practice; or it could be a more formally designed experiment or survey that involves a team of researchers. The same basic steps apply.

In this article, we would like to take you on a behind-the-scenes journey to see how one university researcher followed the scientific method to reach a new opinion about an old idea.

Asking Questions about Soil Balancing

Doug Doohan is a weed scientist and state extension specialist at The Ohio State University. In the 1980s, he read a book called Weeds – Control Without Poisons. The book’s author, Charles Walters, theorized that weeds flourished on a piece of land in response to conditions of the soil. In this theory, weeds are indicators or even stewards of the soil, flourishing to fill a gap in the farm ecosystem. For example, grasses are more common on compacted soils, and certain weeds with deep taproots grow on soils that need nutrients pulled up from deeper soil zones. At the time, Doohan admits he didn’t give the theory much credence. He figured anything that helped or harmed the crop would affect the weeds similarly.

But in 2007, during a study of organic farmers in Ohio and Indiana, he spoke to a group of 30 farmers in depth. He found about half of the group believed that weeds responded intensely to soil management and particularly to managing the relative levels of calcium (Ca), magnesium (Mg), and potassium (K) in the soil, a practice otherwise known as Base Cation Saturation Ratio or soil balancing.

Another observation Doohan took away from these interviews, and others since, was a perceived connection between standing water in the field and weeds.

“Flooding was mentioned specifically as – not just a contributor – but as a major, if not, the major contributor to weed problems and to the spread of weeds,” he recalls. “At first I thought they were talking about flooding along river banks or stream banks.”

But later he came to suspect that they were talking about ponding of water in the fields. Standing water in fields creates anoxic conditions in the soil that impede plants’ ability to exchange air and water with the soil. It almost always leads to poor crop performance and often death.

These two ideas stuck with Doohan – that soil balancing reduces weeds, and that standing water increases weeds. As he began to learn about soil balancing, the two concepts slowly merged into a possible hypothesis.

Forming a Hypothesis on Soil Balancing

Doohan says he had never heard or read an explanation of how soil balancing would affect weed populations. In fact, past research by the scientific community had mostly dismissed soil balancing as an ineffective practice. But it was mentioned often enough by the farmers in his study that he began to wonder if previous research had missed the mark. Why would farmers repeat a practice that didn’t help? And why would the balance of calcium (Ca) and magnesium (Mg) affect weed populations?

From previous research, Doohan learned there was a theoretical basis and at least some evidence that high levels of Mg in the soil, relative to Ca, result in slower drainage or “tighter” soil. Tipping that ratio toward higher Ca, as soil balancing prescribes, may then result in a “looser” soil with better drainage and water infiltration. Ca also helps build organic matter, which aids in water absorption and retention in the soil.

“As we reduce flooding in the fields, we end up with a healthier crop in many cases – a crop that survives, versus a crop that dies out under flooding conditions – and as a result, fewer weeds,” Doohan explains. “When the crop dies or when the crop is not vigorous, what grows in those areas of the field are weeds, primarily. And we’ve all seen those dead areas in the field that come up in foxtail and other weeds.”

Field comparison - flooding
A low spot in a field early and late in the season. Notice the area by the tree line which is flooded and then weedy.

Once weeds get a foothold in the low spots, Doohan says, they can go to seed and become a problem in the healthier areas of the field as well. He found some observational data suggesting grassy weeds may grow better than broadleaf plants in compacted soils. The fibrous root structure of most grasses can grow without penetrating deep into the soil, lending an advantage over many broadleaf plants with deeper-growing taproots.

“What I think we might eventually learn is that soil balancing doesn’t affect weeds directly, but it affects weed occurrence in the field indirectly, because it reduces the likelihood that we would have these anoxic conditions in some fields. I may well be proven wrong, but it’s the best theory I’ve got,” says Doohan.

Testing & Results in Weed Populations

If Doohan’s hypothesis is correct, field experiments should show a shift in weed populations as a soil comes into the Ca:Mg “balance” prescribed by soil balancers. (Traditional soil balancing recommends a base saturation of 65-70% Ca, 10% Mg, and 5% K.)

Over the past four years, the research team has conducted an experiment at two locations – one on a silt loam soil near Doohan’s research facility in Wooster, Ohio, and a second site in Bowling Green, Ohio, with a higher clay-content soil.

Researchers measure weeds in soil balancing test
Ohio State researchers measuring weeds in a test field.

At the Wooster site, researchers compared soils treated with various common soil amendments to change pH and increase Ca or Mg. Treatments included high-calcium lime (CaCO3), gypsum (CaSO4), epsom (MgSO4), dolomitic lime (CaMg(CO3)2), and a control (no treatment).

At the Bowling Green site, the Ca:Mg ratio indicated that the soil was close to “balanced,” so treatments involved adding Ca to maintain balance or adding Mg to force the soil out of balance. (Researchers used gypsum or Epsom.)

From 2015 to 2018, the team tracked many data points, including soil health and fertility, crop yield, and nutrient content, weed emergence, and weed seedbank counts. The team compared results between the treated and non-treated areas. Although they were eventually able to change the balance of the soils with most of the treatments, as of 2017, there were few significant differences to note in soil or crop health between the different treatments.

The lack of early results was no surprise. The research team had helpful input from an advisory board of farmers and consultants. Committee members and others surveyed or interviewed during the project have repeatedly said the process takes time. Since most previous studies on the effects of soil balancing have lasted two years or less, patience was a key element of Ohio State’s study.

Preliminary results from 2018 suggest that soil balancing treatments are beginning to affect the growth of two weeds, giant and yellow foxtail, which both occurred in higher number where Epsom (high magnesium) had been used.

Foxtail weed counts from soil balance test
Average counts of giant foxtail in 2018 weed seedbank samples from an Ohio State test site.
Yellow foxtail counts in soil balancing test
Average counts of yellow foxtail in 2018 weed seedbank samples from an Ohio State test site.

Similar results have not yet been found on the Bowling Green site. However, this summer, for the first time, project researchers found improved water infiltration in Ca-amended versus Mg-amended soils on the heavier Hoytville clay soil at the Bowling Green site.

Conclusions (so far) Concerning Soil Balancing and Weeds

These are exciting numbers for the team after three years of nothing significant to report, but so far the results are inconclusive and do not yet fully support Doohan’s idea that changes in soil structure lead indirectly to changes in weed populations. And even in time, the results may not support his proposed model. Keeping an open mind is a critical aspect of the scientific method. Doohan freely admits there may be a better hypothesis out there or a completely different set of mechanisms at work that would explain his observations. But it’s been exciting to him to reopen the question of soil balancing and to learn from the experience and on-farm observations of growers.

If the team can find additional evidence that soil balancing improves soil structure and water infiltration, it may add an important and accessible management tool to Extension’s list of recommendations — one many organic farmers in the Midwest already appear to be using, according to the team’s survey research.

Doohan cautions that further study will be needed to gain scientific credibility for the long-dismissed practice of soil balancing. For a hypothesis to graduate to a theory and eventually to recommended practice, the steps of the scientific method will have to be repeated by other researchers. And even then, it may not be appropriate for all situations and soils.

“I’m not saying that balance is not important, but what I am suggesting is that, like farmers everywhere, like human beings everywhere, people are looking for magic bullets; and probably soil balancing is not going to be a magic bullet,” says Doohan.

Regardless of what science has to say about soil balancing, he encourages all farmers to review their management practices for ways to build organic matter, for example, the use of cover crops, manures, and compost. Everyone can agree on the benefits of organic matter: increased water holding capacity, a reserve of nutrients, and increased biological activity.

“As an organic farmer, you’re pretty much restricted to the use of physical methods of weed control. And physical methods of weed control – tillage, and cultivation in particular – tend to disrupt soil structure and lead to reduction in high-quality organic matter in the soil.”

Doohan further recommends some common sense approaches to weed control that can be practiced by all farmers: late season mowing to prevent weeds from seeding, cleaning equipment to prevent spreading weed seeds between fields, use of crop rotations to disrupt weed cycles, and just good general crop establishment.

“Anything we can do to optimize the soil for crop growth will help keep down weed populations.”


Learn more about Ohio State’s Soil Balancing team at or in the previous EcoFarming Daily article, “Soil Balancing: Worth Another Look.”

Sourcing Fertility in the Soil

By Charles Walters and Esper K. Chandler

The book Ask The Plant is based on the agronomy of Esper “K.” Chandler, and offers farmers and growers a better way to grow plants that involves reading the unique language of plants, utilizing leaf and petiole testing, and in turn knowing how to produce a better crop using only the fertilizers and soil-building ingredients that are truly needed, when they are most needed.

Instead of following the decades-old conventional model where plants are given copious amounts of soluble nitrogen fertilizers aimed to force-feed the landscape green, Ask the Plant addresses how to build a healthy soil without excessive inputs.

After more than seven decades of soils being mined not replenished, especially of organic matter and minerals — it is time to “ask the plant” and find out what our crops and soils are really telling us so we can produce a better crop using only what is truly needed.

The excerpt below discusses soil minerals, including issues, ideal levels and requirements.

From Chapter 6: Sourcing Fertility

There may be many troublesome words in modern agriculture, but none glows in the dark as much as “conventional.” How a recently minted term such as “conventional” came to label practices less than 60 years old in agriculture, a practice that goes back 10,000 years, surely must puzzle etymologists. Nevertheless, we appear to be stuck with the word, and might as well examine it in the context of modernity.

Calcium (Ca)

“On any soil on any continent,” says Chandler, “we are required to look at the available calcium level, which is possibly the most variable of the elements required for crop growth.” The needs of the soil dictate the kind of lime to be applied. Some soils have fairly good magnesium. Therefore, calcareous sources of lime ask for evaluation. There are many such sources, Chandler cautions. He cites oyster shells, even caliche, and if magnesium is deficient, then high-magnesium limestones are needed.

What, then, is dolomitic lime and what is high-magnesium lime? In Texas, dolomitic lime is notoriously absent, but there are natural lime deposits of 8, 10, and 11% magnesium. “Get to know your highway department because they know where the deposits are,” farmers are often told, and it’s valid advice. “In Texas,” Chandler explains, “most of the local limestone is used in roadbed construction. The Texas-Louisiana Aglime and Fertilizer Association, supported largely by the Sneed family of Georgetown, Texas pioneered the agricultural lime business, supporting research, education, and quality programs for gen­erations. But then when we go to agricultural lime, an overriding factor is the fineness of the grind.” Specifically, it must be ground as finely as talcum powder if it is to be reactive.

This is a basic problem. Chandler learned back in his experimental station days that Arkansas dolomite lime ground only to the fineness of beach sand would have little to no effect on pH. This meant more fine­ness was needed. Such a grind takes a generation of weathering to be use­ful. But lime with the consistency of talcum powder goes to work quickly as microbes break it down to help neutralize the soil’s natural acidity.

The classes and sources of limestone are too numerous to catalog in one sitting. Just the same, mere consideration of the subject makes it necessary to determine what is available to the plant. Or, as Chandler recites, “You have to ask the plant whether indeed it is getting the cal­cium.”

The Rio Grande Valley has soils with 4,000 to 10,000 ppm cation exchange capacity calcium, based on conventional testing. Still, calcium- deficient crops grow on that soil. The lesson is clear. Without the required amount of calcium available, how can such an overload be released? The problem is staggering in its dimensions. Soils well endowed with cal­cium often produce hungry plants because that prince of nutrients is not available. Conventional agriculture asks for water solubility, and yet the natural product often is not water-soluble. In any case, conventional testing does not look at water solubility (available H2O/Ca).

That’s the why and wherefore of calcium, the major building block of all life. Many soils are not well endowed with calcium. Even if mea­sured, the calcium is often not available. The one lesson commercial farming has to face tells us more than a lot of farmers want to know about those microbes. The microbes alone can slowly regenerate the fertility of the minerals. The business of extracting the minerals is one of nature’s finest accomplishments.

Humus and calcium have an intractable partnership in good soil tilth. Calcium is often called the VIP of minerals. Calcium takes top billing in some lab recommendations after humus.

Here, gypsum enters the fray. Chandler puts it this way, “The over­riding factor in getting calcium available is converting it to an available form of calcium-sulfate as gypsum. Enter the sulfur content coming from the natural degradation of organic matter, which contains the sul­fur nutrient, or it has to come from elemental sulfur itself.”

Magnesium (Mg)

The process of loading the soil colloid with an available form of calcium is crucial to cell life. Soil biology is a major factor. From there, the equation progresses to the magnesium factor. Magnesium is not as major an element, but it commands a ratio and has an essential func­tion. Thus, the hunt for sources of magnesium calls up Epsom salts. Magnesium sulfate is a primary source, as is the mined naturally occur­ring mineral called Sul-Po-Mag and K-Mag, which is sulphate of potash magnesium. When conventional agriculture made its case, the rush was on to buy up either magnesium deposits or vulnerable competitors. Magnesium is a finite resource. This reality had smaller companies finding and exploiting smaller veins, now dominated by the marketing name of K-Mag.

Potassium (K)

The next major fertility requirement is potash, often available as K2O. Most sugar crops require more potash than nitrogen. Potash is a natural, mined mineral. It is not a rare earth, but it calls for entrepre­neurial skill and dedication to wrest it from the earth. Deep-vein, hot- water mining in Canada has placed high-cost extraction in the United States onto the back burner. “I’m told that we have some deep deposits of potash in the Rocky Mountains. It can be mined using Canadian tech­nology,” Chandler points out, citing the method that has been proved.

Chandler is more than a little concerned about the future of fertil­izer inputs, not because of technology that powders, prills, and other­wise refines the materials for field distribution, but because sources are finite and use is often wasteful. “We have natural deposits of potash,” Chandler reminds, “from the desert and Dead Sea areas where it has accumulated due to a natural distillation process. These materials have ample amounts of other minerals as well. So, there are many sources of potash, but it is the economic considerations that usually prevail.”

As an aside, Chandler explains the range of the subject to natural/organic folks who often want to prohibit the use of potassium chloride because of the chlorine. This, in excess, is a problem. Unfortunately, “you run the cost up to the natural/organic grower when he or she has to turn to more costly sources of potash,” reminds Chandler, “and potash is one of the largest quantity elements necessary for production of all crops.”

Some soils are well endowed with potash as measured by almost any laboratory inventory, but is it available? And even more important, how can it be made available? To ask these questions is to suggest the availability of an answer. Here is where natural/organic insight comes to the rescue. These denizens of the academic underworld forced down the throats of academia the come-lately consideration of humus, the food for microbial balance in the soil for release of minerals and plant nutrients.

A natural mineral that once figured in the research of William A. Albrecht is langbenite, more commonly known as Sul-Po-Mag, and now as K-Mag. Chandler has extensive experience with this mined product. Langbenite is the basis for both chemical and organic agriculture. It is, as the secondary name implies, a balance of sulfur, potash and magne­sium. Unfortunately, many of the owners of such mines have relegated K-Mag to the back burner of company economics. This means little or no investment in production facilities. Cargill controls both ends of major production. As it stands, fertilizer fabricators literally synthe­size the natural product much as they do all salt fertilizers. The label misleads farmers who often burn crops because they believe the label, thinking their purchase is the real thing.

Most of the firms that control mineral resources are busily consoli­dating, as the saying goes, “into a few strong hands.” The process erases competition, establishes administered prices, and relies on the old iron law of “What will the traffic bear?” Chandler sharply defines secondary minerals as absolutely essential, the primaries being NPK.

  1. (“Potash”) Chandler seldom drops the fertilizer subject or the laboratory equivalent thereof without a word on potassium. Potassium is the largest cation in almost any plant. It usually accounts for more pickup than nitrogen. This appears to be a strange statement since nitrogen has the reputation as a dominant element. There seems to be a natural antagonism between potash and phosphorus. The two are constantly trying to tie each other up, and nature loves balance as much as fecundity.

Now the sequence becomes clear. That overload of phosphorus sup­plied at the beginning of the year tends to run out. Electrical charges figure, most notably the penchant of potassium to tie it up. As phospho­rus uptake falters, so does yield. Small amounts of phosphorus in the drip line along with humic acid doubles the phosphate uptake. Moreover, merely using humic acid can deliver as much phosphate to the petiole as a smaller amount of phosphate alone. The two together seem to double the P uptake. This achievement, faced off against the usual research-proven 5-15 percent P uptake, confers an efficiency on precision agricul­ture only wished for by staid conventional farmers.

Chandler asserts that the above procedure with seaweed hormones and soil inoculants, all together, have quadrupled the effects of available phosphorus. When phosphorus is taken up, so too climbs the uptake reading of nitrogen and all other nutrients. Now Albrecht’s sage obser­vation kicks in. Plants in touch with exchangeable nutrients have the capacity for manufacturing their own hormone and enzyme systems, which are needed to challenge insect predators and crop diseases.

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About Charles Walters

Charles Walters
Charles Walters

Charles Walters was the founder and executive editor of Acres U.S.A. He penned thousands of articles on the technologies of organic and sustainable agriculture and authored many books on the subject, including Weeds: Control Without Poisons, Dung Beetles, Grass, the Forgiveness of Nature, A Farmer’s Guide to the Bottom Line, Fertility from the Ocean Deep, as well as many others. A leading proponent of raw material economics, he served as president of the National Organization for Raw Materials (NORM) and authored several books on economics, including Unforgiven: The American Economic System Sold for Debt and War.

About Esper K. Chandler

Esper K. Chandler
Esper K. Chandler

Esper K. Chandler was a professional agronomist and soil scientist who traveled the country consulting with growers in a quest to improve yields, quality, and profits. He was the owner of TPS Lab for more than 27 years. K. Chandler was a founding member of the National Oraganic Standards Board and a Certified Professional Agronomist (CPAg) by the American Society of Agronomy. He has been proclaimed as a leader in the soil fertility and plant nutrition field. Chandler passed away in 2008.