Soil Fertility: 16 Methods to Understand

By Hugh Lovel

Soil fertility and sustainable agriculture practitioners know that most soils today need their health and vitality rebuilt. In times past, nature built healthy, vital soils, and there is value in copying nature in rebuilding soil health. However, we cannot afford to take millions of years to do so as nature did — we need intelligent intervention. Cultivation, grazing, composting, soil conservation, green manuring, soil testing, soil remineralization, fertilizer priorities, fossil humates, and visual soil assessment all play a role in establishing self-regenerative, self-sufficient, fertile soils.

The biological activities at the basis of self-regenerative soil fertility occur at the surfaces of soil particles where minerals come into contact with water, air, and warmth. It is at these surfaces that biological activities provide nitrogen fixation and silicon release.

Establishing a Self-Sufficient System
In nature, soil organisms cultivate the soil.

Building Soil Fertility

Nature, with minimal human intervention, developed biologically diverse, richly fertile soils and ecosystems with little by way of inputs other than the accumulation of dust, periodic rainfall, fresh air, and sunlight. Rainforests are fertile ecosystems with rich diversity of microbial, plant, and animal species.

While rainforests can be quite fertile, the world’s deepest, richest topsoils evolved as grazing lands — prairies, steppes, plains, savannahs, veldt, and meadows that grew grasses, legumes, and herbaceous plants and supported herds of herbivores along with the predators they attracted.

Andre Leu, Soil Carbon, from the 2007 Eco-Ag Conference & Trade Show. (53 minutes, 44 seconds). Listen in as Leu, the director of Regeneration International, teaches how to store and repurpose carbon in your soil.

In both forests and grasslands,  vegetation draws in carbon. Forests store most of their carbon above the surface of the soil where it cools the earth and helps precipitate rain. Grasslands store more of their carbon in the soil as humus complexes. Forest fires return most of the carbon to the atmosphere, but with grassland fires most of the carbon remains in the soil.

Nature’s way of building soil fertility involves awesome diversity and intense cooperation. Every ecological niche is filled, every need is satisfied, and everything is gathered, recycled, and conserved. No area is left bare, and no opportunity lost. And nature is patient. If something is missing or deficient it may take eons upon eons for it to accumulate from dust and rainfall or cosmic ray bombardment. Nature can also use our help.


In nature, soil organisms cultivate the soil — from the smallest protozoa, arthropods, nematodes, mites, and collembolans to beetle grubs, earthworms, ants, and even larger burrowing animals. Plants and their fungal symbiotes spread rocks and soil particles apart by growing into pores, cracks, and crevasses. They secrete substances that etch the surfaces of rocks and soil particles and feed micro-organisms that free up minerals. Inevitably, at some point, animals will consume the plant roots and open up passages where air and water are absorbed by the soil. Some, like earthworms, grind soil particles up in their digestion processes. They also recycle plant matter as manures, building soil fertility and feeding further growth. This softens the soil and builds crumb structure, tilth, and retention of moisture and nutrients, while allowing water, air, and root penetration. Conversely, continuous grazing — to say nothing of human and machinery impact — compresses the soil and reverses these gains.

Earthworm in soil.

Mechanical cultivation softens the soil and prepares a clean seedbed for planting. For the most part, cultivation destroys soil life and is highly digestive and oxidative. In an age of machinery and power equipment with excessive cultivation and monocropping as the norm, this provides more and faster nutrient release as it collapses the soil biology. More importantly, it depletes nutrient reserves. This leads to higher and higher fertilizer inputs while biodiversity and soil fertility decline.

Even back in the 1920s, Rudolf Steiner saw these trends and introduced horn manure [500], horn silica [501], horn clay, and biodynamic compost made with the herbal preparations [502-507] as remedies. But we also need to reverse the trends outlined above. Too much cultivation burns up organic matter, impoverishes soil life, breaks down soil structure, and releases nutrients that then may be lost. Wind and water erosion may also occur, and the result all too often is loss of soil fertility. The biodynamic preparations are no universal remedy for all mistakes. We must farm sensitively and intelligently as well.

Author and Agronomist Neal Kinsey, Prioritizing Fertilizer Needs, from the 2008 Eco-Ag Conference & Trade Show. (1 hour, 17 minutes.) Listen in and Neal teaches a classroom about how to quantify your fertilizer needs and make a plan for your growing operation.

Various strategies are used for minimizing cultivation damage while still enjoying cultivation’s benefits. Some crops, such as potatoes, require cultivation. But with a mixed operation, crop rotations can take this into account and soil building can still proceed. Strip cropping, composting, and rotations in pasture and hay can help restore diversity so that soil biology recovers. Controlled traffic, where machinery strictly follows predetermined lanes, reduces compaction. No-till and minimum-till planting methods help, especially when used with biological fertilizers and biodynamic preparations to feed the soil food web and take the place of harsh chemicals. Inter-cropping, multi-cropping, and succession cropping increase diversity and reduce machinery impact. Instead of herbicides, managing mixed vegetative cover on roads, access strips, headlands, fence rows, laneways, waterways, and ditches provides biological reservoirs that interact with cultivated areas.


High-density cell grazing is particularly effective. In this technique, large numbers of livestock graze and trample small blocks for a few hours and then are moved on, not to return until plants have regrown. Based on what a pasture needs rather than on a calendar, this could be two weeks, two months, or more than a year.

Sarah Flack, Integrating Livestock into the Farm, from the 2006 Eo-Ag Conference & Trade Show. (1 hour, 32 minutes.) Listen to Sarah’s instructional workshop, as she teaches specific tactics for integrating livestock into your soil management program.

With high-density cell grazing the impact is minimal, and what is not grazed is trampled so the more sought-after plants that get grazed hard have a chance at regrowth. Soil animals recycle what is trampled, feeding it back to the regrowth.


Composting is more than a simple process of digestion and decay. Nature breaks down every sort of organic material into simple carbohydrates and amino acids, but in many cases these would oxidize and leach if there weren’t ways of storing and conserving them in easy-to-use forms.

Bees gather nectar, digest it, concentrate it, and store it in their honeycomb. Similarly, there are microorganisms in the soil that gather up loose nutrients, store them in large, carbon molecules called humic acids and complex them with clay particles in the soil. As with bees, the organisms that gather and complex these nutrients have access to them when needed, and these microorganisms are mainly the actinomycetes and mycorrhizal fungi that form close relationships with plants to the benefit of both. To favor these microbes and their activities, manures and organic wastes can be composted by building stacks, piles, or windrows with a favorable mix of carbon and nitrogen rich materials, soil, moisture, and air. A ratio of 30 to 1 carbon to nitrogen materials along with 10 percent soil and at least 50 percent water is a good starting mix.

Edwin Blosser: Composting Made Simple, from the 2017 Eco-Ag Conference & Trade Show. (1 hour, 58 minutes) Listen in as Blosser, the founder of Midwest Bio Systems, explains how to make compost, and how it can be used on a commercial scale.

Into the newly built pile, insert a small spoonful of each of the herbal “composting” preparations described in Steiner’s agriculture course. In the case of the valerian flower juice tincture, the liquid is diluted in water, stirred intensively, and sprinkled over the pile. Sprinkling the horsetail herb over the pile before covering can also help.

These preparations impart a balanced range of activities that assist and improve the breakdown and humification process. A covering of some sort will be very helpful in providing an outer skin or membrane that holds in the life and vitality of the compost heap as it matures. Once it is stable with most of its nutrients bound up in humic complexes, its microbial activity should be rich with nitrogen-fixing, phosphorus-solubilizing, and humus-forming species.

Using the composting preparations is equally important in large-scale composting operations, whether piles are frequently turned or left static.

Biochemical Sequence of Nutrition in Plants

Plant biochemical sequences begin with: 1. Boron, which activates 2. Silicon, which carries all other nutrients starting with 3. Calcium, which binds 4. Nitrogen to form amino acids, DNA, and cell division. Amino acids form proteins such as chlorophyll and tag trace elements, especially 5. Magnesium, which transfers energy via 6. Phosphorus to 7. Carbon to form sugars, which go where 8. Potassium carries them. This is the basis of plant growth.

Soil expert and author William McKibben, The Art of Balancing Soil Nutrients, from the 2009 Eco-Ag Conference & Trade Show. (1 hour, 8 minutes). Listen in as McKibben talks about the steps you can take after you receive your soil test results to help balance your soil.

However, consider the economies of scale. On the one hand, Steiner indicated that each preparation need only be inserted in a single place — even in a pile as large as a house — and its effects would radiate throughout the pile. On the other, since Steiner’s death special composts known as manure concentrate, Cow Pat Pit (CPP), and barrel compost contain all the herbal preparations in one easy-to-use formula that can be stirred intensively for 20 minutes and sprayed throughout the pile as it is assembled or added to the water used to moisten the compost. This can bring the benefits of the preparations into a large-scale operation economically.

Some composters prefer to use the horn preparations with the herbal preparations, and a biodynamic agriculture Australia formula called Soil Activator combines all the preparations in one compound that is stirred and applied like CPP. According to John Priestley, one of Australia’s most experienced and innovative biodynamic farmers, “the only way the biodynamic preparations don’t work is if you don’t use them.”

Volatilization & Leaching

A criticism identified by organic farm research is volatilization and leaching from raw animal or plant wastes. These losses can be pollutants in the atmosphere, in waterways, or in the water table. Biodynamic management of plant and animal wastes prior to application on soils involves composting of solid wastes and fermentation of liquids, such as effluents, with the herbal preparations. All materials need to be broken down into stable humus or stable liquid brews before use. Proper application of the full range of biodynamic preparations ties up loose nutrients and minimizes run-off or leaching. Rank manure smells are a sure sign of nitrogen loss and are also an invitation for weeds, pests, and diseases. This is neither a plus for soil fertility nor a plus for the environment. Wherever animal wastes collect or nitrogenous materials break down, soil or rock powders can be scattered and CPP or Soil Activator sprayed to minimize losses and keep smells in check.

Cover Crops & Green Manures

In general, cover crops and green manures are quick-growing annual plantings of grasses, legumes, and herbaceous species intended to rebuild soil biology, restore nitrogen fixation, and provide material for grazing, composting, mulching, or ploughing back into the soil. In some cases seed is harvested off of these mixes before they are grazed, composted, used for mulch, or ploughed down. Applications of barrel compost, CPP, or Soil Activator can assist in rapid breakdown, re-incorporation, and humification of these green manures.

Clover Field

Ideally, cover crop mixtures should include at least 15 to 20 species of annual grasses, legumes and herbs. These can restore diversity; rebuild soil biota; conserve loose nutrients; help with pest, weed and disease control; increase soil carbon; conserve moisture; reduce run-off; and prevent erosion — while protecting what might otherwise be bare soil.

South Dakota farmer Gabe Brown, author of Dirt to Soil, speaks in 2016 at the Eco-Ag Conference and Trade Show. (1 hour, 18 minutes.) Listen in as Gabe Brown talks about how he uses cover crops to build soil health.

Broad-acre cover crops may be under-sown with succession species to take over after harvest. Or cover crops may be planted as catch crops at the end of growing seasons. They may also follow short season crops depending on region and climate, and they can provide handy ways to feed rock powders and composts to the soil biology. Vegetation is almost always a plus, while bare soil ensures the opportunity is lost.

For example, a winter crop of oats, lupines, rape, clovers, and corn salad could be taken to the point the grain and other seeds are harvested and separated. Alternatively, mixes of winter cereals, legumes, and broadleaf plants might include wheat, barley, rye, triticale, vetches, clovers, medics, turnips, mustards, rape, and radishes. If the area in question is to be used as pasture, perennial grasses, legumes, and other species such as dandelions, plantains, chicories and yarrow may be sown along with the annuals as succession species. For summer covers, a mix may include different kinds of sorghums, millets, cowpeas, lablab, maize, soybeans, and buckwheat, harvested either green or at seed to be milled for animal feed. Experiments along these lines were pioneered by Colin Seis of Winona Farms in Australia. Direct seeding (minimum or no-till) of a diversified mixture of compatible annual species into existing vegetation, such as pastures and hayfields, shows considerable promise for soil improvement and increased forage yields, and at the same time reduces risks where droughts can be followed by floods that would devastate cultivated soils.

Soil Testing

Before bringing in manures or mineral inputs it is important to have reliable information about what is already there. Soil testing can be helpful, but it also can be misleading. Since the birth of chemical agriculture, most soils have been tested for soluble nutrients using dilute solutions of mild acids in an attempt to mimic the weak acids plants give off at plant roots. This ignores the wider range of soil biology and assumes plants only access those elements in the soluble form as shown by the testing method.

Neal Kinsey, Using Soil Analysis to Grow Crops, from the 2005 Eco-Ag Conference & Trade Show. (50 minutes, 12 seconds). Listen in as agronomist Neal Kinsey, the author of Hands-On Agronomy, teaches about how to test your soils, and use that data, to increase crop yield and decrease weed pressures.

In his retirement, Justus von Liebig, the father of chemical agriculture, realized he was wrong in thinking plants depended on solubility. Rudolf Steiner took up the challenge of correcting Liebig’s errors in his agriculture course. Time passed, and Ehrenfried Pfeiffer, who worked closely with Steiner in his agricultural research, immigrated to the United States after World War II and set up testing laboratories in Spring Valley, New York. He conducted extensive total testing of soils and found that most soils contained large quantities of nitrogen, phosphorus, and potassium that didn’t show up on soluble tests. These were the very elements being applied in large quantities to agricultural crops, though soils continued to decline in fertility.

In many cases, soil biology, given encouragement and sufficient trace elements, would provide access to the insoluble but available nutrients stored in the humic fraction of the soil. However, fertilizer industries using soluble testing as a sales tool and selling farmers minerals they already had in abundance were unstoppable. They perpetuated Liebig’s errors and financed ongoing research into solubility-based agriculture, building a momentum that relegated Liebig’s final wish to obscurity.

Today in Australia, Environmental Analysis Laboratories at Southern Cross University in Lismore, New South Wales offers both the soluble Albrecht test and a hot aqua regia total digest test similar to the one Pfeiffer used. EAL accepts samples from anywhere in Australia or the world.

The Albrecht test measures the ratios of calcium, magnesium, potassium, and sodium, which are the major cations or metallic elements in the exchangeable portion of the soil. The ratio of calcium to magnesium is particularly important for soil mechanics. Heavy soils may need as high as a 7-to-1 ratio of calcium to magnesium to crumble and expose particle surfaces. By the same token, light soils may need more like a 2- or 3-to-1 ratio to hold together. Other soluble analysis targets of importance for robust, vigorous growth include 50 ppm sulfur, 2 ppm boron, 100 ppm silicon, 70 ppm phosphorus, 80 ppm manganese, 7 to 10 ppm zinc, 5 to 7 ppm copper, 1 ppm molybdenum, 2 ppm cobalt, and 0.8 ppm selenium.

In total tests, the targets for nitrogen, phosphorus, and potassium depend on the carbon content of the soil, since most soil reserves are stored in humus or accessed by humus-based organisms. Most importantly, total testing addresses what is contained in the soil reserves despite what may seem like deficiencies in soluble tests. As Pfeifer discovered, it is common to find huge reserves of phosphorus, potassium, and other elements that are deficient in soluble tests, which indicates something else is going on.

The Biochemical Sequence

There is a hierarchy or biochemical sequence of what must function first before the next thing and the next thing works. The elements early in this sequence must be remedied before later elements have much effect. Nitrogen, phosphorus, and potassium occur late in this sequence, while sulfur, boron, silicon, and calcium start things off.

Since everything going on in the biology of the soil occurs at the surfaces of soil particles where minerals combine with water, air, and warmth, sulfur is the essential key-in-the-ignition for activating the soil biochemistry.

Neal Kinsey, Compost & Manure Analysis, from the 2005 Eco-Ag Conference & Trade Show. (50 minutes, 39 seconds.) Listen to Neal Kinsey’s helpful lecture on how to test compost and manure, to ensure those inputs are balancing your crops and soil.

Sulfur works at the surfaces, boundaries, and edges of things to bring life and organization into being. It is the classic catalyst of carbon-based chemistry. Regardless of the other soluble elements in the soil test, there should be 50 ppm sulfur [Morgan test] for biological soil fertility to function properly and a 60 to 1 carbon to sulfur ratio in the total test.

Silicon & Boron

Silicon forms the basis for the capillary action that transports nutrients from the soil up. Fortunately for agriculture, the activity of silicon is to defy gravity, but this silica activity relies on boron, a component of clay, to do so. Boron is the accelerator while silicon is the highway. If either boron or silicon is deficient, the soil biology will function below its potential. Ironically, the most effective way to make sure boron and silicon are deficient is clean cultivation and heavy use of soluble nitrogen fertilizers. This is modern agriculture.


Calcium, which comes next in the biochemical sequence, is the truck that travels on the highway. It collects and carries with it the nutrients that follow in the biochemical sequence. As the opposite polarity from the aloof silicon, calcium is hungry, even greedy. Calcium engages nitrogen to make amino acids (the basis of DNA) RNA, and proteins. These in turn are responsible for the complex enzyme and hormone chemistry of life that utilize magnesium, iron, and various trace elements as well as depending on chlorophyll and photosynthesis for energy.

Photosynthesis is where magnesium, phosphorus, potassium, and a wide range of micronutrients follow nitrogen in the biochemical sequence. Unfortunately, NPK fertilizers stimulate this latter portion of the sequence without addressing the priorities of sulfur, boron, silicon, and calcium. The NPK approach usually grows crops that are highly susceptible to pests and diseases.

Minerals & Rock Powders

Even though biodynamics is primarily about organization and biological activities, soil mineralization must be considered. It is pretty hard to organize something if it isn’t there. Many soils need gypsum or elemental sulfur. Many soils also need boron, especially after nitrogen fertilization, but also following overgrazing or clean cultivation. Silicon may also be needed to get the soil biology up and running so it can release more silicon from the surfaces of soil particles. It too is depleted by overgrazing, clean cultivation, or nitrogen fertilization. Many ‘organic’ farms using raw manure — especially chicken manure — as a nitrogen source, which deplete their sulfur, boron, and silicon.

In addition to silicon rock powders, lime provides calcium; dolomite provides magnesium; and rock phosphorus provides silicon, calcium, and phosphorus. There are also natural potassium sulphates, and many rock powders provide trace elements. For high pH soils with large excesses of sodium and potassium, the remedy may be humates and zeolite to buffer pH and build additional storage capacity.

Gary Zimmer, Gaining a Working Knowledge of Calcium, from the 2002 Eco-Ag Conference & Trade Show. Listen to Gary Zimmer talk about how calcium drives the flow of other minerals and nutrients through the soil and plant, and how to measure and balance calcium levels in your fields.

Most importantly, the biochemical sequence shows us we need to start with a full correction for sulfur to expose the surfaces of soil particles to biological activity before the biochemistry can kick in. Other methods may not recognize sulfur’s key importance, but in biodynamics this should be clear. Liebig’s ‘law of the minimum’ rightly says plants only perform as well as their most deficient nutrient.

Calculating Inputs

A soil test can show how many parts per million (ppm) of each element are present and whether target levels are being met. The question is, how can we calculate the right adjustment and add no more and no less? Fortunately there is a rule of thumb.

Two-hundred and fifty kg/ha (250 lbs/ac) of any input supplies that input’s percent analysis as parts per million. Note: This is based on the average weight of the top 17 centimeters of soil in 1 hectare, which is approximately 2,500,000 kilograms (to calculate, 2,500,000/250=10,000 which is 1 percent of 1 million parts per million). Since a hectare is 2.5 acres and a kilo is 2.2 pounds we can approximate this rule fairly closely using 250 pounds per acre in the place of kilos and hectares. For example, if the soluble test for sulfur (Morgan test) shows 5 ppm when the target is 50 ppm, then 45 ppm sulfur is needed. If gypsum is 15 percent sulphur, then 750 kilograms per hectare (750 pounds per acre) gypsum will deliver 45 ppm sulfur. If gypsum is 20 percent S, then 565 kilograms per hectare (565 pounds per acre) will be required. If the gypsum is 12 percent S, then nearly a metric ton per hectare (or 1,000 pounds per acre) is needed.

Since gypsum is calcium sulphate, it provides both calcium and sulfur, which is usually desirable. However, in the event that the soil is already rich in calcium and has a pH of 6.3 or higher, elemental sulfur may be a better choice. In contact with moist soil, sulfur will oxidize to sulphate and lower the pH slightly, but it will open up the surfaces in the soil, stimulate soil biology, and release some mineral reserves. For practical purposes, elemental sulfur may be combined with 10 percent bentonite for ease of handling. Ninety percent elemental sulfur would require 125 kilograms per hectare (125 pounds per acre) to deliver 45 ppm S.

As a different example, sodium molybdate is 42 percent molybdenum. To add 0.5 ppm Mo to the soil requires 42 divided by 0.5, which equals 84. If we divide 250 kilograms by 84 we get 2.976 kilograms sodium molybdate. However, to add this much in one go would be expensive and unwise. With most inputs, especially the traces, the soil has trouble adjusting to a full correction of anything other than sulfur. In the case of sodium molybdate, 0.5 kilograms per hectare (0.5 pounds per acre) is the usual correction and 1 kilogram per hectare (1 pound per acre) is considered the limit. The maximum manganese or zinc sulphate per application per hectare is 25 kilograms per hectare (25 pounds per acre), and copper sulphate rarely is applied at any rate higher than 15 kilograms per hectare (15 pounds per acre).

Boron, Humates, and Trace Minerals

When adding trace elements, especially boron, feeding the fungi of the soil food web is essential. Fungi hold on to inputs that would otherwise leach. If available, well-humified compost produced on the farm is highly desirable. If this is not available, then other humic inputs must be considered. Humic acids are extracted commercially from carbon-rich deposits such as leonardite, soft brown coal, and peat. While raw leonardite or brown coal may be processed and sold as raw humates, the extracts, sold as soluble humates, are a handy food concentrate for actinomycetes and mycorrhizal fungi, which are amongst the most important microorganisms for nutrient retention and delivery in the soil. Soluble humates and raw humates are excellent for buffering boron and trace elements such as copper, zinc, manganese, or sea minerals. They also are helpful when adding bulk minerals such as gypsum, silica rock powders, lime, rock phosphate, or potassium sulphate. Trace elements may be combined with 250 kilograms per hectare (250 pounds per acre) of raw humates or 25 kilograms per hectare (25 pounds per acre) soluble humate extracts in dry blends, or they may be dissolved in liquid soil drenches with soluble humates and water. This delivers them to the soil’s fungi, which hold on to and deliver them to plants.

Crusher Dusts

Siliceous rock powders such as granite or basalt crusher dusts only provide silicon from the surfaces of their particles, but they can be helpful in repairing silicon deficiencies while the soil biology starts releasing the soil’s silicon reserves. Siliceous rock powders can be fed to the soil biology along with humates as a food source, and the actinomycetes and mycorrhizae will gradually weather the particle surfaces and release silicon. Crusher dusts are especially effective when fed to pigs and their manure is composted. They also can be added to composts or spread along with composts. Generally 2 or 3 tons per hectare will produce a helpful response, and these rock powders also usually release boron, which is especially essential for legumes.

Lime, Rock Phosphate, Potassium Sulphate, etc.

Each of these has its own story, and, as Pfeiffer discovered, the soil total test is a better indication of whether these are needed than the soluble test. If deficient, any of these can be built into soils by inputs, with the caveat that it is not a good idea to add bulk lime to composts. Lime should not be added to compost at more than 0.1 percent of the total mass, as it tends to drive off nitrogen as ammonia. It can be spread along with composts, but when added to composts at more than 1 kilo per ton it tends to waste valuable nitrogen.

Visual Soil & Crop Assessment

Visual soil assessment is helpful in order to evaluate soil biology. New Zealand soil scientist Graham Shepherd has published a book on this titled Visual Soil Assessment Volume 1: Field Guide for Cropping & Pastoral Grazing on Flat to Rolling Country. While it may not be the last word on the subject, it is a surprisingly good start toward evaluating soils, their conditions, and their biological activity. This system assesses texture, structure, porosity, mottling, soil color, earthworm activity, aroma, root depth, drainage, and vegetative cover.

There also are many visual clues to mineral deficiencies. For example, hollow stem clover, lucerne, beans, and potatoes indicate boron deficiency. Boron deficiency is also indicated by high Brix in the early morning, which shows that plants are holding their sugars in the foliage and the cycle of root exudation is not occurring at night.

Dwarf leaves in clover indicate zinc deficiency. Purpling of grass and clover in winter indicates copper deficiency, and so on. Poor chlorophyll development and pale, yellowish green vegetation often indicate magnesium deficiency on a magnesium-rich soil. This is common where the soil is too sulfur deficient to release magnesium properly. Under these conditions, foliar analysis usually shows high sulfur because what little sulphate is present is soluble and plants take it up even though there is not enough in the soil for magnesium release. This slows growth and sulfur builds up in the plant because it is not being used. Adding magnesium to a high mag soil will only make matters worse, while the real cause of magnesium deficiency is the first priority of all soil amendment programs — sulfur.

Soil consultant Noel Garcia, with Texas Plant & Soil Lab, speaks at the 2014 Eco-Ag Conference & Trade Show, on the Critical Growth Stages for Optimum Production. (1 hour, 15 minutes.) Listen in as he teaches a class on how to monitor plants for stress, and mineral and nutrition deficiencies.

The taste and smell of vegetation can be clues of excess nitrate uptake and poor photosynthesis, while complex, delicious flavors and aromas indicate high Brix and nutritional density. Biodynamic growers should be aware that their own senses can be the best guide to determining what is going on with pastures and crops. Sending soil and plant specimens to laboratories for analysis is a useful tool for learning what the senses reveal, but firsthand observation is quicker as well as less expensive, and it can be far more informative.

Nitrogen Fixation and Silicon Release

Nitrogen and silicon are present in enormous abundance, though this usually goes ignored. Nitrogen fixation and silicon release should be the highest priority in agricultural research. If growers knew how to access nitrogen and silicon in abundance, it would eliminate the larger part of their fertilizer costs, to say nothing of most of the rescue remedies for weeds, pests, and diseases. Unfortunately, little funding is available for such research since industrial concerns would suffer if this knowledge became widespread.

The nitrogen fertilizer industry currently uses 10 units of methane to manufacture 1 unit of ammonia. With a little more energy, this can then be converted into urea and applied as fertilizer. With straight urea applications to the soil, losses of 50 percent and more are normal, since large amounts of nitrogen evaporate as nitrous oxide (N2O) when the urea oxidizes.

The same 10 to 1 carbon to nitrogen ratio holds true for biological nitrogen fixation since it takes 10 units of sugar from photosynthesis to fix 1 amino acid. However, the losses are nowhere near as great. The grower’s challenge is making photosynthesis as efficient as possible so that biological nitrogen fixation is abundant.

Nitrogen fixation is more robust when plants have steady access to all the necessary requirements for efficient photosynthesis. This feeds a steady abundance of carbohydrates to their microbial nitrogen-fixing partners in return for amino acid nitrogen. Biodynamic farms attain this level of mineral balance and photosynthetic efficiency when everything is working near optimum. This deserves replicated scientific trials, but it hardly makes sense to wait for funding when there isn’t any money to be made from the research. Farmers must simply try their hand at it. Some will undoubtedly succeed with relative ease while others will find it difficult for a variety of reasons.

Silicon, Nitrogen, and the Soil Food Web

The previous subheading on soil testing indicates optimum levels of minerals for plant efficiency and nitrogen fixation. Though these guidelines are generally higher than those considered adequate in chemical agriculture, these levels are desirable for efficient photosynthesis, especially at lower temperatures. This is particularly true for silicon, which is almost always deficient in conventionally-farmed soils. Silicon, and its co-factor, boron, are the principal keys to transport speed, which is the key to abundant photosynthesis in plants. Energy must be transferred from the chloroplasts in the leaf panel to the leaf ribs where sugars are made. Silicon is basic to fluid transport, and this transport determines how fast sunlight is converted into sugar.

Nitrates, nitrites, and other nonorganic forms of nitrogen impair the silicon chemistry of the plant as well as the symbiosis between plants and their microbial partners in the soil — unlike amino acid nitrogen, . Raw manures and poorly composted manures, especially raw poultry manure, are extremely detrimental because of the nitrate burden they impose on the soil biology. Nitrates flush silicon out of both plants and soils. How well a plant picks up silicon from the soil depends, at least in part, on the level of actinomycete activity at its roots. This in turn depends on the extent to which the soil opens up and is aerated, which in turn depends on sulfur levels and soil microbes such as Archaea that digest siliceous rocks. The sensitive biochemistry of these activities, in both soils and plants, is impaired by high levels of nitrates.

Animal activity in the soil around plant roots provides freshly digested amino acid nitrogen, which encourages the release of silicon from the surfaces of soil particles. Living in partnership with plant roots, actinomycetes form fine fuzz along the root exudate zone of young roots, and nitrogen-fixing microbes make this their home. In the process, the actinomycetes utilize the silicon and boron in forming their fine, fuzzy hairs. As roots age and mature, these microbes are consumed by soil animals ranging from single-celled protozoa upward. The nutrients they excrete are taken up as nourishment by plants, often providing a high proportion of amino acid nitrogen and amorphous fluid silicon.

Soil microbial life can only access silicon at the surfaces of soil particles where moisture, air, and warmth interact. The rest is locked up. Nitrogen fertilizers, particularly nitrates, suppress actinomycete development and the nitrogen-fixing microbial activity they host. On the other hand, if actinomycete activity is robust, the soil food web freely provides a luxury supply of both amino acids and amorphous fluid silicon.

Biodynamic practices promote this activity as a way to achieve quality production that sustainably and efficiently rivals the yields of chemical agriculture. The bonus comes when environmental conditions are less than ideal. Biodynamic production can then easily surpass chemical yields.

Hugh Lovel is an agricultural consultant serving clients in both the United States and Australia. He consults, speaks, and teaches on all aspects of agriculture. For more information, visit

This article appeared in the July 2014 issue of Acres U.S.A.

Biochar: Helping Everything from Soil Fertility to Odor Reduction

By David Yarrow
From the March 2015 issue of Acres U.S.A. magazine

Biochar is a valuable soil amendment. It has gained much attention in recent years for its ability to boost soil fertility and microbiology, upgrade soil structure, and accelerate plant growth. Amid a rising tide of research and trials, what was once mostly fuel or water filtration media has suddenly sprouted dozens of innovative applications and benefits.

Researchers and farmers are have discovered many new uses for biochar, including:

  • Stormwater management and treatment
  • Phosphorus traps to reduce water pollution
  • Nitrogen traps to reduce ammonia and nitrate pollution
  • Reclamation of mine tailings
  • Building material blended with cement, mortar, plaster, etc.
  • Electronic microwave shielding
  • Electron storage and release as a “super-capacitor”
  • Carbon fiber textiles for odor-absorbent clothing
  • Carbon nanofibers to replace plastic and metal

Livestock farming is offering a new and growing area of unexpected uses for biochar. Animals from earthworms to chickens, cattle, and even monkeys show shrewd interest in biochar when it is added to their food. Farmers and scientists around the globe are investigating the use of biochar in livestock production. In the European Union, biochar is carefully defined and approved for use in agriculture, with most fed to livestock or spread on farmland with manure.

This article mainly addresses poultry production, but similar issues and opportunities face other livestock producers. Research from several countries shows that adding one to three percent biochar to cattle feed improves feed efficiency by 28 percent, reduces methane by 25 percent, and increases rate of weight gain by 20 percent.

Biochar in Poultry Farming
Farmer Josh Frye with his gasifier.

Biochar Added to Litter

An immediate use of biochar in poultry farming is to reduce — and even eliminate — odors from poultry litter, particularly ammonia. Biochar adsorbs gases, liquids, and ions, and ammonia (NH4+) is all three. Adsorption is the adhesion in an extremely thin layer of molecules to the surfaces of solid bodies or liquids. Activated carbon’s effectiveness for odor control is well-known and is preferred in air purifiers. Farmers can spread a blend of 5 to 10 percent biochar with conventional litter on a barn or coop floor.

Ammonia’s strong positive electric charge makes it corrosive and toxic to breathe. This gagging gas is emitted by bird droppings, creating air that is unhealthy and toxic to birds and humans. Ammonia irritates skin on contact and degrades even hard tissue, such as hooves. It also attracts insects, such as flies. This is one reason biochar can even serve as a fly deterrent. (Related Read: Non-Toxic Control of Common Insects)

Adsorption with Biocarbon

Biochar is extremely porous, making it an excellent natural filter with a huge internal capacity for water and ions. It has a more robust appetite for ammonia, ions, and other irritants and nutrients than any other organic material.

Biomass burned or baked with little or no oxygen is “reduced” to a very black, inert, dry, porous substance. In this contracted, scorched state, char is ready to vigorously attract and absorb minerals, molecules, ions, electrons, and even photons.

black ashes biochar
Biochar is extremely porous, making it an excellent natural filter with a huge internal capacity for water and ions.

Careful attention to biomass source, temperature, and time can produce a grade of biochar optimized for this barnyard adsorption service. Research at several universities shows activated carbon captures up to 63 percent of ammonia emitted from poultry poop. Char also curbs methane, nitrous oxide, hydrogen sulfide, urea, organic acids, ketones, volatile vapors, and noxious liquids. Biochar keeps these chemicals safely in litter, rendering them non-toxic and immobile and converting them to precious nutrients. Biochar doesn’t do all this on its own; it supports minerals and microbes that are needed to digest, break down, and convert wastes.

Depending on the type of litter, biochar can be mixed 5-10 percent by volume with litter. Effects are strong at 5 percent biochar and reach saturation beyond 15 percent. For best effect, biochar should be screened to a uniform particle size (1/4 to 1/16 inch); cleaned of dust; mixed with calcium, trace elements, clay and rock flours; lightly moistened; and inoculated with digestive bacteria and fungi. With straw pellets as litter, char is best added at the pelleting stage.

Reduced ammonia is a major health improvement for the environment, the birds themselves, and farmworkers. Lower moisture content and ammonia levels curtail risk of footpad diseases, skin lesions, and respiratory afflictions.

Because biochar also absorbs liquids, it changes the physical quality of poultry poop. Floor droppings are far less sticky — almost dry — and are lighter in weight and easier to handle, allowing litter and bedding to be managed with greater safety and sanitation.

Farmers commonly add lime and other cations to litter to help reduce odors and raise pH. Biochar’s high adsorption capacity means less lime is needed, since calcium and other cations are adsorbed into char micropores and delivered with greater efficiency. Char captures and conserves calcium and other cations, holding them where microbes and roots can access them. This further reduces ammonia emissions and improves litter’s value as a soil amendment.

Char can also be added when making silage. Char binds well with silage, providing its usual benefits of conserving moisture, buffering pH, retaining cations and anions, and providing stable refuges for fermenting microorganisms.

Biochar in Compost

When litter or bedding is spread on land, significant nutrients outgas and leach. Biochar bestows significant extra capacity to adsorp and hold nutrients in composting materials. It improves retention of ammonia and other valuable nutrients, beginning with nitrates and phosphates, with far less lost as gas and leachate. Biochar also retains water in its micropores and keeps moisture in the composting biomass.

Biochar is derived from plant biomass and creates an environment that benefits cell biology. Providing air, water, and nutrients favors healthy, beneficial microbes to improve composting rate and digestive efficiency. Biochar micropores are ideal refuges for bacteria and fungi, so adding this uniquely inert biocarbon stabilizes, strengthens, and sustains compost’s teeming populations of digestive organisms. Compost containing three to five percent biochar will likely be a higher quality premium fertilizer with more nutrients, better physical properties, and more vigorous, healthy microbial communities.

Biochar as Feed Supplement

Farmers who add biochar to litter soon notice birds peck at bits of char. They deliberately eat char — an intentional behavior. Substantial data on four continents consistently reveal that biochar as a feed additive provides direct benefits to livestock.

Dr. Casey Ritz at the University of Georgia began researching adding char to poultry bedding to control ammonia in 2007. He showed that it reduces ammonia outgassing by converting it to stable ammonium. Ritz wondered if he could do this inside a chicken.

chickens walking around in barn with hay

“We must stop ammonia before it’s made, instead of trying to mitigate it after it’s emitted,” said Ritz. “Char is a strategy with a good chance of success.”

Ritz fed chickens feed with three-percent activated carbon added, while another group received normal feed with no char. Ritz found significant drops in ammonia in manure from char-fed chickens compared to chickens given regular feed.

One Missouri farmer who feeds his chickens char observed, “When dressing chickens, I examine their gizzard and craw. I see black bits of char used to grind food. In gizzards, they’re ground smooth, almost-oval, with round ends, shiny, like river stone. So, biochar is introduced before intestinal digestion — like they chew food with charcoal teeth. Nutrient absorption starts immediately.”

He adds, with emphasis, “No ammonia smell — or any other smell, for that matter!”

The small, polished black balls form by abrasion with pebbles and food particles in the gizzard. Very fine carbon powder ground from bits of char is a catalyst to improve digestive efficiency. This benefit is both chemical and biological: it increases ion adsorption and transport while improving microbe function so the birds hardly excrete nitrogen as waste ammonia at all. Instead, nitrogen is now more fully metabolized into amino acids, which can then become proteins. Birds thus exhibit better weight gain and growth.

Chicken feed is usually light brown, but char turns it black. Happily, the color doesn’t bother chickens. Char also changes the color of their manure.

Biochar as a Digestive Catalyst

Charred carbon has no nutrient value for animals. Scientists say it is “only a filler” in feed, this understates char’s significant roles. As in soil, char provides essential services beyond being a nutrient source.

Biochar is a catalyst that brings essential elements, especially charged ions, together to encourage their reaction, but biochar itself remains largely unchanged by these reactions. Biochar provides sheltered spaces and selective surfaces for ions and microbes to assemble and interact.

Biochar is also a catalyst to facilitate populations of microbes. Many bacteria, fungi and other simple life forms take up residence in char micropores. Feeding biochar stimulates beneficial bacteria in the GI tract to strengthen digestion and immunity. It can increase nutrient adsorption, retention, and transport to improve the liver-intestine circuit.

Biochar’s probiotic benefits improve if char is pre-inoculated with digestive microbes. A fully probiotic approach must adapt to unique conditions and needs, though. A microbe culture for seed planting is different than for compost tea, or cooking compost, or foliar feeding spray, or planting trees; each must be modified to meet its specialized environment and purpose.

Biochar promotes digestion and improves feed efficiency and thus increases energy gained from feed. Toxins effectively bind to biochar, mitigating adverse effects on the digestive system and intestinal flora. The health and vitality of animals also improves, as will meat and egg production. With animals’ immune systems stabilized, infection risks from pathogens decrease.

Scientific experiments attempt to determine how much char to add to poultry feed for optimum effects, but most often char is raw and is not pre-charged with minerals or pre-inoculated with microbes. Dr. Ritz’s best guess, based on experimentation, is one or two percent of feed. His results align closely with those from Asia, Europe, Australia, and India.

Wider adoption of this old substance for this new use in farming is encumbered by three major obstacles:
• Farmers need equipment and businesses to produce and sell affordable biochar for poultry producers as a feed additive.
• The FDA, USDA, organic certification agents, states, and other regulatory bodies must review and approve char as a feed additive. Activated carbon is already approved for human use.
• We need to develop formulations of biochar with minerals, microbes, metabolites, and other nutrients, as well as protocols for use in varied farm operations and crops.

Converting Poultry Litter to Bioenergy

Some poultry farmers are beginning to produce biochar themselves. Plant biomass isn’t the only material that they can convert to char — manures can also can be dried and then burned or baked into biocarbon. Developing activated carbons and char from broiler litter is a very effective way to reduce waste volume and treat waste emissions.

Mississippi State researchers compared char made from poultry litter with commercial activated carbon made from coal for air purification. The poultry litter was mostly pine shavings plus the poop. Lab results suggest char from litter performs as well or slightly better than the commercial product.

This reduces the need to use high-value feedstocks or hard-to-harvest sources to make biochar. It rather allows farmers to convert an abundant on-farm resource — manure — into assorted valuable products, starting with bioenergy and biochar for soil.

USDA researchers recently found that charred poultry manure is extremely effective at selectively adsorbing heavy metals such as mercury, lead, and cadmium. Scientists now speculate about creating “designer biochars” tailored for specialized uses.

Combining Heat, Power and Biochar

Carbonizing manure also yields heat and can produce syngas and bio-oil for on-farm power and fuel. Gasifiers burn biomass to generate heat as well as biochar. But baking biomass by pyrolysis (coking) allows extraction of useful gas and liquid biofuels. These are well-developed technologies, but they must be adapted to make low-temperature biochars for soil.

Most poultry barns are heated in winter and early spring, and many farms burn propane to produce this heat. Burning propane produces excess moisture, though, and imported fossil fuel is expensive. A chicken producer typically spends at least $20,000 each winter on propane heat.

An alternate approach is heaters that burn biomass and yield biochar as by-product instead of oxide ash. Three immediate, abundant, cheap farm feedstocks are cornstalks, manure, and sawdust. Controlled combustion technology can capture 20 to 50 percent of biomass carbon as biochar. By restricting airflow and controlling time and temperature, farms can cut costs for off-farm fuels and fertilizers and make on-farm energy, soil amendments, litter additives, feed supplements, and water purifiers.

Biochar from Poultry Litter

In Wardensville, West Virginia, third-generation poultry farmer Josh Frye raises 800,000 chicks a year. He used to burn propane to heat his barn in winter so he could maintain production. A friend suggested a biomass gasifier that could extract energy from his own poultry manure. Frye learned that the gasifier would also yield biochar, a non-odorous soil conditioner and fertilizer.

For gasifier technology to meet his needs, Josh selected a fixed-bed gasifier built by Coaltec in Illinois and designed by Westside Energies of Canada. Coaltec helped him apply for grants to purchase and install a $1,000,000 unit. A 30-by-50-foot fixed-bed gasifier installed in March 2007 burns at low temperatures to produce biochar and heat. The maximum feed rate is 1,000 pounds per hour; this yields 5 million BTU of heat plus 3 to 4 tons of char.

Frye’s gasifier began operating in 2009, producing high-quality biochar and fossil fuel-free heat. He sold his first biochar ton at a net price of $480 a ton to a New Jersey farmer to test on corn and soybeans. A South Carolina farm is testing the char on pharmaceutical grapes. With help from International Biochar Initiative (IBI) leaders Johannes Lehmann and Stephen Joseph, Frye optimized his gasifier to make char rich in phosphorus and potassium. Test burns have produced P at 1.7-3.2 percent and K at 5.4-9.6 percent.

The first year of test burns produced 30 tons of biochar and saved 4,000 gallons of propane. Frye eventually expects to cut propane consumption by more than 80 percent. He also wants to use gasifier heat in the summer to run a chiller to cool his poultry barns.

Frye’s annual production of 125 to 600 tons of poultry litter yields 25 to 120 tons of biochar. His gasifier-produced biochar has a 10 to 34 percent carbon content. Carbon content largely depends on manure moisture content. Lower moisture yields higher carbon biochar.

“I feel I’m making a real contribution to the ag world,” said Frye. “Converting a raw waste to stable carbon-rich biochar is great.” In 2009, the West Virginia Department of Environmental Protection awarded Frye the first-ever “Clean Energy Award” for his poultry litter gasification.

Biochar from Sawdust

In Columbia, Missouri, Phil Blom of TerraChar works with Roger Reed, a combustion engineer, to install furnaces that burn sawdust into biochar to heat a boiler and heat exchanger. Reed adapted his sawdust burner to restrict air supply and make fine-texture biochar instead of ash. His high-efficiency, automated, low maintenance, small-scale gasifier uses air to move sawdust through a combustion zone and can be adjusted for other feedstocks such as corn stover, shavings, or pellets.

These burner-boiler systems are installed in barns to create hot water and deliver radiant heat. This eliminates excess moisture from burning propane. Sawdust biochar is then mixed with litter to mitigate ammonia and other odorous gases and eventually ends up in soil as nutrient-rich, composted manure.

The system they are currently building will produce 2.5 million BTUs of radiant heat per hour to heat two poultry barns. The equipment will consume 300 tons of biochar a year from 1,500 tons of sawdust biomass. In addition, the new system will send excess heat from the burner-boiler to a steam-driven 60 kilowatt-per-hour electric generator. The farmer will save up to $2,000 per month in electric expenses in addition to savings from avoided propane expenses.

David Yarrow has taught about and helped people build sustainable food systems in the Northeast United States for more than 30 years. He can be reached at For more information, visit


David Yarrow, TERRA: 573-818-4148,,
Phil Blom, Terra Char: 151 Dripping Spring Road, Columbia, MO 65202, 573-489-8929,,
Josh Frye: PO Box 218, Wardensville, WV 26851, 540-550-8856,,
Hans Peter-Schmidt: farmer and researcher, Ithaka Institute, Switzerland,
Casey Ritz, Ph.D.: Poultry Science, UGA, Athens, GA 30602; 706-542- 9139,,
Kari Fitzmorris Brisolara, ScD: Environmental and Occupational Health, Louisiana State University, School of Public Health, 2020 Gravier Street, New Orleans, LA;
Dana Miles, Ph.D.: USDA-ARS-Mississippi State, P.O. Box 5367, Mississippi State, MS 39762;
Isabel M. Lima, Ph.D.: USDA-ARS-SRRC, P.O. Box 19687, New Orleans, LA 70179; resources

By David Yarrow. This article was first published in the March 2015 issue of Acres U.S.A. magazine.

Wood Ash: How to Make Your Own Fertilizer

By Jon Frank

Wood ash can be a resource for making your own super fertilizer: You’ve heard of super foods — foods especially endowed with nutrition that merit special attention. I would like to suggest a simple, effective fertilizer you can make yourself.

Often overlooked and many times deprecated because it was over-applied — it is time to give wood ash its due. If you burn wood for home heating you already have a ready supply. If not, all it takes is a bonfire and you are in business. I like to incorporate plenty of charcoal in combination with the wood ashes.

This approach is more closely aligned with the creation of Terra Preta. To cut the dust, I like to mix wood ashes with moist leaf mold. You may want to en­hance your fertilizer by mixing 1 pound of kelp meal and 1 pound of sugar for every 20 pounds of ashes. If phosphorus is low in your soil, add bones to the bonfire and crush them with the charcoal.

I suggest using anywhere from 5 to 50 pounds per 1,000 square feet. Avoid using on soils with a pH above 7.8. The use of wood ash does not replace soil test and fertility recommendations; rather it supplements it and reduces the overall need to purchase costly off-site inputs. The beauty of using wood ash is that the spectrum and ratio of minerals present in the ash have already been preselected by plants. Its fine dust is very fast-act­ing in soil. Wood ashes are very rich in trace and secondary minerals, without adding nitrogen.

wood ash
Straight wood ash on the right and wood ash mixed with ground up charcoal on the left. Both will benefit most soils.

Beyond Wood Ash

To create an optimum growing environment in your garden take these actions:

  • Keep the mineral levels in your soil well supplied;
  • keep soil-applied nitrogen very low;
  • keep the soil consistently moist, and
  • make your own super fertilizer.

And now for the word of caution. Externally applied nitrogen is a safety net. Its use should not be discontinued in the following situations:

  • Indoor growing — Greenhouses and high tunnels are very intensive and require more production to remain profitable.
  • Commercial grain production — Don’t even think about it.
  • Soils heavily sprayed with herbicides and pesticides — The microbial system struggles in this environment and requires applied nitrogen.

For more information about fertilizer, visit the Acres U.S.A. bookstore or subscribe to Acres U.S.A. magazine.

Organic Fertilizers for Horticulture

By Louise Placek

If you are growing commercially, no matter what you are growing in containers or what soil mixture you use, you will need to fertilize. This is especially important during active growth when nutrient needs rise sharply.

In addition, during the warm/hot months, increased watering washes nutrients out of the soil and these nutrients need to be replaced in the form of a soil drench or foliar application. Feeding your newly planted plugs regularly is important, at least until they have an established and healthy root system. Plants whose root sys­tems have been even slightly disturbed in transplanting will need extra nourishment until the new roots have formed.

Commercial growers most often use chemical fertilizers because it is the easy way to get nutrients to the plant. These fertilizers come in many formulations of NPK (nitrogen/phos­phorus/potassium) and are easy to apply as a liquid soil drench, in time-released pellets (“prills”), or granular forms that are mixed into the soil. Some are formulated to “force” specific types of growth such as foliage or flowers. They are also designed to move growth along at a quick pace to get plants out to the nurseries in a timely manner. Fertilizer is especially important when the grower is using a soil-less mix.

Call me an organic purist, but I tend to equate chemical fertilizers with heroin. The plants will be fine as long as they are getting the steady supply of calculated N-P-K. In fact, they will respond quite well. Several things bother me about this process. One, the fertilizer was made in some chemical-manu­facturing lab and it is totally artificial. Two, I have a problem force-feeding any living thing. Three, a plant grown this way is like building a house with cardboard rather than bricks; the plants just don’t hold up in the long term if exposed to any stress.

A model of a tank fertilizer system.
A model of a tank fertilizer system. Courtesy of Made from Scratch.

When a plant is allowed to grow at a genetic rate (rather than a chemically calculated rate) it will have a stronger overall constitution. When you give your plants a natural, earth-made fertilizer it is like sitting down to dinner for the plant. If it is hungry, it will use what is available. If not, it won’t. Simple, gentle and sensible. Folks, I could pay my July electric bill if I had a dollar for every time someone has said to me, “Your plants look so healthy.” That’s because they are. Anyone can grow plants, but to grow sturdy, vigorous, vital plants takes a different frame of reference and mind—it becomes a thing of beauty.

Fertilizers and Soil Amendments You Need

The following is a basic list of fertilizers and soil amend­ments that can be used in organic horticulture. It is not intend­ed to be comprehensive; it is meant only to acquaint you with some of the most common products and how they are used. I will not even mention N-P-K numbers as people depend too heavily on these when trying to decide on a product. Natural products such as these generally do not have high N-P-K num­bers, but offer a wealth of readily available nutrients to plants in a living soil.

Alfalfa Meal

Alfalfa is a perennial legume that is used as fodder for animals, green manure for crops and, when cut, dried and ground into a meal, it makes a great soil amendment. Some of the many nutritional benefits alfalfa meal offers are nitrogen, phosphorus, potassium, calcium, magnesium, trace minerals, triacontanol (a growth stimulant), sugars, starches and a bank of amino acids. It can be mixed directly into your soil or made into a “tea” and used as a soil drench or foliar spray. If you make the tea in warm weather, don’t let it sit more than a couple of days. The smell will knock your socks off.

Blood Meal

This is dried, slaughterhouse blood. Very mal­odorous and rather expensive. High in nitrogen. Probably bet­ter off in your garden than in your soil mix.

Bone Meal

A by-product of the meat industry, bone meal is animal bones that have been pasteurized, dried and ground into a powder. Used as a calcium and phosphorus amendment, but also contains some nitrogen. Can mix directly into your soil or dip your plug roots that need extra calcium into the meal before planting.

Note: In an organic setup, both bone meal and blood meal should be used only if there is nothing else available that will provide the same benefits. There also should be a full disclosure of where the bone or blood meal is from and how it was processed to avoid contamination of organic plants with products that are not organic.

Calcium Sulfate

Gypsum, as it is commonly called, is a mined or industrial by-product material used to correct calci­um deficiency (especially in alkaline soils) and to loosen up tight clay soils allowing better drainage, which can release excess sodium if present. Would be used in garden soil for the most part, but is good to know about.

Colloidal Phosphate

Often referred to as soft rock phos­phate, this is mined, crushed phosphate that has been sus­pended in clay. Good, long-term source of calcium and phos­phorus. We dip our flowering-fruiting plug roots in the powder before planting.


Although many different organic substances are used to make compost, the fundamental nature of it is the same. The end product is the result of digestion of these sub­stances by microorganisms (bacteria, fungi, etc.) and some macro-organisms such as earthworms. The process releases nutrients from the original material and creates a soil condi­tioner rich in humus, humic acid, vitamins, minerals and nitro­gen.

Final analysis of any compost depends on what original materials were used. Some commonly used are manure, cotton burr, vegetable and other plant waste (hay, grass, leaves, tree twigs/bark, etc.), mushrooms, rice hulls, paunch manure (cow stomach contents), and even the hulls of certain nuts. Compost can be worked into the soil, used as a mulch/top-dressing, or made into a “tea” and used as a soil drench or foliar spray. (For more information on compost see Chapter Six.)

Cotton Burr Compost

Another by-product of the cotton industry, this is the wickedly sharp calyx of the cotton flower in which the boll rests. There is only one company I know of who uses only organic cotton burrs and aerobically composts them into a wonderful, earthy soil amendment. As with the seed meal, it is a good, slow release source of nitrogen, phos­phorus and potassium. I’m in love with the smell. I use the fine-screened product in my soil mix.

Cottonseed Meal

A by-product of cotton ginning, the seed is ground into a meal and used as a soil amendment. It is a slow-release nitrogen, phosphorus and potassium source. This is a good product, but due to the large number of chemicals used to grow cotton (pesticides, herbicides), one should be certain that the source of the meal is only from organically grown cotton. Good luck.

Earthworm Castings

Earthworm poop is finely digested organic matter. It has all the same basic benefits of compost, but in a more compact, easy-to-use form. This is a great addi­tion to potting soil and even can be used safely in plug mix­tures. Commercially available from small earthworm farms.

Fish Emulsion

As the name implies, it is an emulsified fish by-product in a concentrated form. When mixed with water it can be used as a soil drench or a foliar spray. It is valued for its nitrogen, phosphorus and trace minerals. When I first started using fish emulsion, I was not sure I was going to be able to get past the smell. I found that not only did I get used to the smell, it was virtually gone by the next day. Most importantly, my plants love it.


This coarse-grained, light-colored, hard igneous rock is often used by landscapers in crushed (gravel-like) form as mulch and in garden pathways. In organic horticulture the sand or meal is mixed with soil as a source of potassium and other trace minerals.

It also has paramagnetic properties, which as you recall, helps other nutrients become more avail­able to the roots. If possible, try to find the partially decom­posed granite.

Green Sand

Mined from ancient ocean beds, this silica-based material—officially called glauconite—is greenish colored sand that is loaded with potassium. It also contains iron and other elemental nutrients. Best if used in a soil that has good microbial activity.


This is aged, dried poop from bats and sea birds. Most of what you see commercially is bat guano, but some garden supply catalogs have droppings from birds that live on sea cliffs. They are all high in nitrogen, humus (a good soil builder), microorganisms, vitamins and minerals.

It is good stuff, but has a very strong urine-like odor. I would avoid top dressing the soil of pots with it because it has an odd, almost greasy consistency when wet and just doesn’t seem to work its way down like compost. It is better worked into the soil ahead of time. It is a fine powder so you should wear a mask when mixing it.

Lava Sand

Generally a combination of crushed volcanic rock often including basalt. Can be used as a soil amendment for drainage, minerals and paramagnetic properties.


This is a general term referring to the various white, powdery materials containing a substantial amount of calcium carbonate. Some also have a generous amount of magnesium, so before using as a garden soil amendment do a soil test and see what you really need. Often used to adjust an acid soil pH higher.

Caution: do not buy lime intended for industrial use as it may have toxic heavy metals.


Any animal manure can be used as a nitrogen source in soil mixes as long as it has been well aged, pasteur­ized and/or composted. Some might be considered mild enough to use directly, but why take the chance? Different manures have varying levels of nitrogen.

I would check out what the animals are being fed. If the manure is full of hor­mones, antibiotics or other chemicals, you will not want to grow plants in it. Always wash your hands thoroughly after handling manure of any kind—better yet, wear gloves.


This sweet, thick, black syrup is a by-product of the cane sugar industry. It comes in various grades, but the blackstrap grade retains the most nutritional components and is good for people as well as plants. Molasses can be added to foliar sprays or to soil drenches and adds iron, sulfur, potassi­um and other trace elements as well as sugar to feed the ben­eficial micro-organisms in the soil and on plant leaf surfaces. Can be used as a “sticker” instead of soap or oil when spraying botanicals for insect control.


This product is kelp that is ecologically harvest­ed, dried and ground into a powder. It comes to you in either powder or liquid concentrate. Mixed with water, it can be used alone or with fish emulsion as a foliar spray or soil drench. This is the “black gold” of organic fertilizers. Packed with trace min­erals and natural hormones, this product not only fortifies overall health but assists in the uptake of other nutrients.


This yellow powder is a natural mineral that binds with calcium in garden soil to bring an alkaline pH down. Often called elemental sulfur or flower (flour) of sulfur.

Source: Made from Scratch

Homemade Fertilizers

By Hugh Lovel

With the economy and farm finance more and more problematic, interest is growing in running farms with fewer, more accurate, and less expensive inputs and homemade fertilizers can help cut costs and keep fertility on the farm.

Formerly we’ve overdosed with a plethora of harsh fertilizers — especially nitrogen. As a result we’ve burned up the better part of our soil carbon, and this has reduced our rainfall.

By burning off carbon, we have created droughts even as ocean warming has sent more evaporation into the atmosphere. We have ignored that few things have more affinity for hydrogen than carbon, and if we want rain to adhere to and permeate our soils we need to build soil carbon.

We thought salt fertilizers were cheap, and the stunning results encouraged us to wish away any hidden costs, no matter that earthworms disappeared simultaneously with the food chain that supported them. Our soils got hard and sticky as magnesium stayed behind while nitrates leached, carrying away silicon, calcium and trace minerals. The soil fused when wet, shed water when it rained, and we continued to get less for more.

As if this wasn’t enough, the mind-set we were sold was get big or get out. As our net margins dried up and our future prospects evaporated, our water dried up and our land became exhausted.

Vermiwash made with loving attention in a small biodynamic apple orchard in the Himalayan foothills of Uttaranchal in sight of Nanda Devi, India’s second highest mountain.

Around the world agriculture is and will be limited to its available water. Along with carbon dioxide and nitrogen, water is a gift from above — but we don’t seem to know how to use what could be ours for free. Between hardening our soils and deepening our creeks we’ve managed to speed most of our rainfall away, making flash flooding a norm in many areas.

We use salt fertilizers on cropland and scald soil microbes, burn up soil carbon and make crops thirsty, watery and weak, which invites pests and diseases and further seduces us into a dangerous dance with poisons. At one time the cheap availability and industrial scale of inputs made this sort of agriculture seem efficient.

However, the inevitable result can no longer be ignored — progressive degradation of our land and an attendant rise in degenerative diseases with cancer and heart disease leading the cue. Our only sensible choice — the only choice left — is to learn to work with what nature gives us for free.

As far back as 1924, Rudolf Steiner, foreseeing the current conundrum, emphasized in his lecture cycle, “Agriculture,” that the primary requirement for healthy farms and gardens is self-sufficiency. In his words, “Properly speaking, any manures or the like which you bring into the farm from outside should be regarded rather as a remedy for a sick farm.”

While this is an ideal and not something we can fully achieve, it should be obvious that best practice requires slashing inputs, rebuilding soil carbon and making the most of homemade fertilizers.

This starts with rediscovering how to use the current atmospheric surplus of CO2 and water along with the abundance of nitrogen we’ve always known was there. Even though a few off-farm inputs like sea minerals will always be beneficial, self-sufficiency would make most farming enterprises winners in building life and complexity back into the soils and crops we as a society depend on.

The first step is conservation of carbon and water, as well as improving our nitrogen fixation. We should keep in mind that what we export from our farms or gardens, including hay, manures, packing house wastes, wood waste, etc., should not exceed 8 or 10 percent of our total biomass production. The other 90-92 percent of what we take from the atmosphere must be built into the soil to sustain and enhance life.

Based on economic analyses, farms get into trouble when they export more than 8 percent of their annual biomass production. The internal farm economy is of primary importance and export has to be secondary for the farm to generate its own fertility. Many modern farms — especially those exporting hay, silage and sugar cane — would not fulfill this requirement.

Life as we know it is carbon-based, which means building carbon in the soil is the key to agricultural self-sufficiency. Relying on artificial nitrogen inputs shows no signs of getting us there, as studies have shown that for every unit of artificial nitrogen applied, somewhere between 15 and 30 units of soil carbon are consumed — though in the days of cheap nitrogen fertilizer this fact went ignored.

In those days scientists tended to think of nitrogen fixation as something to do with legumes, suggesting that legumes fixed a bit of nitrogen, while ignoring the fact that it wasn’t the legumes that fixed the nitrogen. Rather it was symbiotic microbes living in nodules on legume roots that accounted for this nitrogen fixation, and no one seemed to care what the legumes did to make themselves such beloved hosts for these microbes.

It was assumed that legume nitrogen fixation could be measured by assaying the nodules, and if no nodulation occurred, no nitrogen was fixed. Even though grasses supplied much more carbon to the soil, since they did not nodulate they must not feed nitrogen fixation, so forget nitrogen fixation with sugar cane, maize, sorghum, wheat and so forth — the “wisdom” was to supply artificial nitrogen to these crops.

This was science wearing blinders in the service of industrial profits at its worst. Even as microbiologists identified and cataloged nitrogen-fixing species by the thousands, most of which had nothing to do with nodulation, our agricultural schools and researchers continued to teach that it made no difference where the nitrogen in agriculture came from, and no effort was made to investigate the carbon requirements of nitrogen fixation and how natural nitrogen fixation compared to the energy required for chemical substitutes.

The fact that many grasses host nitrogen-fixing microbes that live as endophytes within the tissues of their leaves and stems was a topic to be avoided at all cost.

Now we have to learn nature’s delicate mechanisms for giving various crops the few mild boosts they need — more during early conversion — to maximize photosynthesis, carbon sequestration and nitrogen fixation. We have to learn how to increase our biomass production while slashing inputs and send higher quality products to markets, and the ins and outs of building fertility by balancing lime and silica, photosynthesis, nitrogen fixation and biomass recycling while we export our surplus.

Nature has always done this without inputs, which should give us many hints. Our problem is we are in a hurry and most farmable land today is in a bit of a coma. This poses the question of how can we generate the necessary inputs at home and on the farm while buying in as little as possible?

Think about the internal logic of setting up our farms to generate robust fertility at minimum cost while becoming more and more regenerative into the future. In countries like Australia and the United States, this may mean downsizing so we can handle the delicate adjustment of it all, but surely this is the future of agriculture.

Homemade Fertilizers: Vermiwash

Also known as earthworm leachate, vermiwash is most valuable as a food source for beneficial microbes that activate our soil reserves and whatever inputs we use. To make vermiwash, set up covered earthworm tanks with a good mix of brown/tough and green/soft wastes along with soil and any available manures.

worms in compost
The worm composting is a great fertilizer

For the home gardener this may be lawn clippings mixed with shredded fallen leaves and kitchen waste, along with mineral additives such as rock powders, bone meal or ash. Be sure to mix in at least 10 percent good soil containing clay and earthworms.

For small market gardens this may mean collecting old bathtubs, placing caulking screens in the drains and plumbing them at a slight slant on blocks or on the edge of a low wall so that light watering produces a rich, brown leachate that drips out into buckets under the drains.

Keep in mind the importance of a small percentage of clay-rich soil, preferably living clay/humus rather than something refined like bentonite, but use whatever clay is convenient. Water lightly daily and collect the vermiwash from the drains as a liquid fulvic/humic concentrate that easily combines with other inputs such as potassium silicate.

Because various plants strongly accumulate trace elements, the end product can be engineered for sulfur, zinc, phosphorus, iron, etc. by feeding the earthworms specific local weeds, an art form to experiment with.

Lucerne accumulates gold, and tobacco accumulates uranium. Tall woody weeds tend to accumulate potassium, while flowering plants like tobacco weed and salvation Jane accumulate phosphorus along with the necessary copper and zinc to unlock it from otherwise inaccessible reserves.

Humic and fulvic acids are formed when organic materials like cellulose are broken down into simple sugars and built back up into complex organic clay/humus complexes. Where cellulose is glucose, a very simple sugar, beneficial soil microbes rebuild this into complex molecules that contain all sorts of organic compounds including amino acids and chelated minerals. The molecular weights only go up to a couple thousand atomic weight units in the simpler fulvic compounds, but for the more stable humates they go up to 10,000 or more.

Particularly the humus compounds lock up nutrients so they don’t show up on soluble soil tests, and only the fungi and actinomycetes that build and store these compounds in the soil have access. This is nature’s wisdom at work, as these crop-beneficial organisms are storing up tucker for themselves. While mycorrhizae and actinomycetes can access the humates, bacteria for the most part cannot.

This makes the nutrients minimally soluble but nevertheless available, which tends to reverse leaching. For a bacterial/protozoal-dominated earthworm operation with an emphasis on readily available nutrients, use more manure and straw and less clay or rock powder. This favors the small, red earthworms found in most manure piles. The leachate then tends to be rich in the lower molecular weight fulvic acids. However, raising larger earthworms requires a more actinomycete/fungally silica-dominated mix with more woody materials, as well as more clay or rock powders.

Moderate doses of rock phosphate and other rock powders can be very helpful, especially crushed basalt or granite, as these are rich in boron, silica, calcium, phosphorus, potassium and other trace minerals. Be sure to include enough grit for earthworm appetites, as earthworms have no teeth. Instead, like chickens, they have gizzards to grind their food. It also helps to include mineral-rich wood waste like milled tree bark. This tends to yield more fungal dominance and more of the high molecular weight, stable, clay/humus complexes.

Cover the earthworm tank(s), with something such as plywood, which will attract life force but sheds rain. Water each tank, perhaps with a liter or two of water each day, so the vermiwash drains out and can be collected in a bucket.

Older material and earthworms can be removed for other uses such as starting new tanks. A mix of new raw materials should be added regularly to keep the process going. The resulting vermiwash can be used by itself or in combination with other inputs. For best results, biodynamic preparations should be included in one form or another, perhaps as versatile, easily applied pre-mix.

Homemade Fertilizers: Potassium Silicate Watering Solution

The most common deficiency seen in both agriculture and human nutrition is silica. This recipe makes cell walls strong and plants disease- and insect-immune.

An industrial version, marketed for large commercial growers, was researched by the USDA and found to be the most effective preventative for fungal problems in both wheat and tomatoes.

One may purchase high purity potassium silicate used commercially as a pottery wash or glaze. It is made by burning potassium carbonate at 2300°F with finely ground sand or glass. The resulting slag is ground upon cooling and dissolved in water with a generous release of carbon dioxide.

The classic Aussie recipe uses the dried foliage of our Australian she oaks or bull oaks. In North America and Europe the classic recipe uses horsetail herb, which grows abundantly in silica-rich places. In either case one burns a large quantity to ash and collects the ash.

The ash of any silica-rich plant material will do. For example, rice hulls (not the bran but the hulls) are brilliant and even bamboo will do. Mill ash from sugarcane

bagasse is available at some sugar mills in vast bulk at industrial prices. These ashes are rich in potassium and silica.

Growers may multiply this recipe accordingly, but on a small scale, simmer at least 30 minutes while stirring 2 to 3 kilos of high silica ash in 16 liters of water in a 20-liter pot, possibly adding a kilo of diatomaceous earth if high-quality ash is hard to obtain. Unless you know your land is rich in boron, add half a cup of Solubor or boric acid. After stirring and simmering for 30 minutes, allow to cool to a pleasantly warm temperature. Strain and filter to make a lye-like solution rich in soluble potassium silicate, which will be rich in available fluid silica.

Add a heaping tablespoon of biodynamic horn clay and stir homoeopathically (this refers to rhythmic shaking, aka succussion, or stirring (potentization) where the creation of a series of alternating left and right vortexes are involved) for three minutes. Keep in mind that adding boron will activate silica in the soil and bolster sap pressure in plants.

When applying, combine the potassium silicate solution with vermiwash at a rate of 250 milliliters of potassium silicate per liter of concentrated earthworm juice. Dilute this concentrate at least half and half with water (more is good) and apply to the soil in the market garden, orchard or vineyard as needed. Like everything, this can be overdone, so it is suggested to limit applications to a liter of this combination per fortnight per plant with such produce crops as pumpkins, squash, sweet corn, cucumbers, zucchini, capsicums, okra or anything else with a tendency to get too lush, weak, bug bitten or diseased.

(Note: Do not overuse this formula. Even on high organic matter soils, which greatly buffer the effects, no more than eight times in a growing season should be plenty. A rule of thumb in agriculture is that if a little bit is good a little bit less more frequently is better.) The rate of potassium silicate can be doubled for tomatoes, which easily get too lush, and the vermiwash can be cut back to one-half or one-quarter the former rate.

If organic certification is an issue, these ingredients are all naturally occurring materials except Solubor, which is permissible in most organic certification programs due to widespread boron deficiencies in most cultivated soils.

There will be considerable residual ash left after straining and filtering which will need to be turned into a resource. These strainings can be blended back into compost/vermiwash production or incorporated into solid fertilizer blends such as humified compost and scattered on grain, pasture or hay paddocks.

For larger growers a commercially available buffer — usually allowed in organic programs — is soluble humate, which is a fungal food that directs the potassium silicate to the mycorrhizal fungi and into the plant in much the same fashion as vermiwash.

The Biochemical Sequence

Keep in mind that boron activates silica to make it more fluid, and best practice is buffering boron with carbon, preferably a fungal food source rich in high molecular weight humic acids. The idea is to feed the soil food web so the plant can exchange energy in the form of living carbon for a steady feed of amino acids and mineral chelates from the soil.

biochemical sequence of nutrition in plants chart

For this to work properly it helps to observe the natural biochemical sequence in living organisms — what elements must work first before other elements can become useful. Boron and silicon have long ranked as the least understood essentials in modern agriculture. Silicon has been ignored for almost a century and a half, and boron, though known to be essential, is poorly understood. Since the biochemical sequence shows how much everything else depends on boron and silicon, the combination of potassium silicate and vermiwash is likely to be a mainstay in the fertility program of market gardens, orchards, vineyards and flower and herb production.

In general this formula works well for fertigation (where liquid products are put out in irrigation water). It may not be so much used as a foliar unless it is used as a base for homeopathic applications of biodynamic preparation patterns, color or other quantum energy applications. If it is used as a foliar, keep in mind that boron provides sap pressure, which works from the soil up in order to get silica and all the other nutrients into the plant.

If boron is applied as a foliar it must get to the roots before it becomes effective. Ordinarily boron and silica enter plants via actinomycetes and mycorrhizal fungi. These organisms are delicate and are easily impaired by salts such as NPK fertilizers. Damaging them will greatly reduce nutrient uptake, especially for boron, silicon, calcium, amino acid nitrogen and zinc. When using this formula in foliar applications, dilute the boron tenfold.

Used sparingly in foliar and fertigation programs this combination considerably strengthens the silica containment and transport features of everything in the market garden, orchard, vineyard or nursery.

Homemade Fertilizers: Bone Ash & Sulfur

Phosphorus can be particularly elusive, and calcium is not far behind. But the element we really must watch — because it is the catalyst for all life chemistry — is sulfur. Depending on time and place, sulfur falls freely with the rain.

Among other elements it will be present in humates and vermiwash. Sulfur works on the edges and boundaries of things along with silicon, potassium and zinc. Life arises at these boundaries. The richer and more interactive these boundaries

are the more abundantly they give rise to life, which is where syntropy and entropy meet.

Syntropy is where available energy accumulates instead of dispersing as occurs with entropy. For more than a century it was fashionable to assert that all heat-driven systems invariably ran down, and entropy was enshrined as universal in what was called “The Second Law of Thermodynamics.” However, living organisms quite obviously both accumulate and disperse available energy.

Thus they can concentrate a stream of order on themselves and grow, as well as running down as may be the case. Depending on the location and condition of the soil, sulfur applications (usually as gypsum, aka plaster, where available) deserve careful consideration.

Manures and certain vegetative plants, such as most legumes, may supply the sulfur needed to enliven the silica/phosphorus/sulfur/calcium spectrum in the soil. When all its components are working harmoniously this spectrum is like a bridge that sets the stage for natural nitrogen fixation to build to levels sufficient for high-production agriculture.

Particularly on pastures, the soluble phosphorus on a soil test may be only a few parts per million (ppm), while a total soil digest with aqua regia may reveal 1,000 to 3,000 ppm of P. The occurrence of a red wine color in petioles and leaf tips is an indication of insufficient available phosphorus, but this does not tell us how much P is actually there or what needs to happen to make it available — hence the need for a total test. Because we ultimately depend on life to release bound phosphates, plants may need small amounts of soluble phosphorus to utilize the energy bound up in carbon compounds so they can release more of the phosphorus reserves in the soil.

Of the elements needed in steady supply, phosphorus best shows us the need for both soluble and total tests to see what is actually there. If phosphorus is plentiful in soil reserves we only need to prime the pump with a bit of soluble phosphorus and a microbial food source — such as vermiwash and/or molasses — in order to start unlocking the reserves. Here is where homemade bone ash can provide enough soluble phosphorus to prime the pump that opens up phosphorus reserves. Only when phosphorus is missing should it be added in bulk quantities.

Gather bones and burn them completely so that they can be crushed into powder. In the case of fresh bones, it may be necessary to compost or cook the meat off them prior to burning to avoid waste and objectionable odors. In some cases waste bones, including heads, may be available from abattoirs or processing facilities in large quantities, and it may be more economical to grind them up with a stump grinder and incorporate them into compost windrows. At least they should never be wasted, and provided the necessary machinery is available this may be a preferred solution.

In general, however, burned bones may come from almost any source, and some will burn more easily than others. This bone ash powder can be applied loosely and sparingly to the soil.

To kick-start the phosphorus processes may require a little more readily available phosphorus, however. Thus the freshly crushed powder can also be cooked in water as with the potassium silicate and used at similar rates. If sulfur is needed to get things going, this is where elemental sulfur or gypsum should be added.

Cooking bone ash in water will access readily available phosphorus, which is useful in the short term even though it is only a fraction of the total phosphorus in the bone ash.

The addition of elemental sulfur can significantly assist in solubilizing more of the phosphorus, while the residues can be added to compost piles or vermiwash tanks.

As the bridge between lime and silica (the oxides of calcium and silicon), phosphorus is key for both storage of energy in photosynthesis and for the use of energy by the soil food web. Even though phosphorus is No. 6 in the biochemical sequence, it nevertheless must be working in order for soil microbes to have the energy to make potassium reserves available. Quite commonly soluble levels of potassium in soils are rather marginal, and before the crop cycle is finished more potassium will be needed than shows up on soluble tests. Only rarely is this not present in the soil reserve, but until phosphorus is functioning properly it is not likely to become available in desired amounts.

Of course, most agronomists are in the business of selling potassium so they advise just whacking extra potassium on in soluble form. However, too much soluble potassium suppresses microbial release of potassium reserves and is not advisable if one wants to get off the input treadmill. Besides we have already attended to soluble potassium in a small way by making our own potassium silicate solution. This will be sufficient that we can usually attend to the rest of our potassium needs by maintaining a modest but steady phosphorus availability.

Homemade Fertilizers: Humified Compost & Compost Extract

Misunderstandings about compost abound. Many imagine that composts are simply digested, broken down organic matter that is ready to be taken up by plants. With this in mind many composters seek to simply digest such organic complexes as wood wastes, plant matter, manures and protein-rich wastes with little or no thought of the stability or final use of the product. From this point of view composts often are evaluated by how much soluble N, P and K they provide, with the assumption that the higher the levels of solubles the better.

Unfortunately such composts feed rampant bacterial flushes that grow better weeds than crops and pollute streams and groundwater with runoff and leaching.

In making its own composts, nature is far wiser as its most beneficial soil organisms gather up nutrients in the soil like bees gather nectar in the fields, and they store these nutrients so they become insoluble but available.

Actinomycetes and mycorrhizal fungi store and have access to these humified nutrients, making them available as plants grow as soon as root emergence and root exudation occurs.

Often what we think of as weeds are nature’s back-up team to sop up loose nutrients when humification has not occurred. We would see this in the first few weeks of plowing down a green manure crop. For the first three weeks or so bacterial breakdown of vegetation runs rampant, nutrients are released, and if we plant before the humus-builders take over we get a field of weeds that overwhelms whatever crops we planted.

In composting, the breakdown phase runs rampant at first, producing simple sugars, amino acids and soluble salts. However, this sets the stage for organisms, which clean up this heady brew — toning down the nutrients to non-toxic levels and quelling bacterial activity while storing large organic clay/humus complexes that sequester amino acids and mineral chelates so they are insoluble but available. It is in these large, stable compounds — available to crop beneficial microbes — that the most beneficial forms of boron, silicon, calcium, nitrogen, magnesium, phosphorus, potassium, zinc, etc. are held.

Most soils, abused though they may be, have remnants of these beneficial soil microbes that can be awakened if they have a proper food source — humified compost — to nurse them back to the point they can resume their roles.

Awakening these beneficial microbes primes the pump for further humus formation as plant root exudates feed these microbes in garden, orchard, pasture and broadacre operations. At some point such re-enlivened soils can reach a level of biological activity and become self-fertile and self-sustaining with diversified cropping and carbon farming.

This also means that in the near term liquid extracts of humified composts can be of especial benefit to boost this recovery when used as liquid injects on top of seed at planting. Often in broadacre and pasture renovation, liquid inject formulas based on compost extracts or liquid humic and fulvic concentrates can be the most economical way of feeding this all-important microbial population where it can do the most good — on new roots as they emerge. In garden and small farm applications this is essentially what is accomplished with vermiwash, and such liquid formulas can be sprayed as with vermiwash on stunted areas in pasture and broadacre paddocks.

Homemade Fertilizers: Large-Scale Humic & Fulvic Extracts

Sometimes when we are dealing with grazing or broadacre acreages where the scale is too large to address needs with on-farm composting it can be useful in the short term to bring in humates in the form of activated brown coal solids or humic and fulvic extracts. In general these inputs are excellent in rebuilding soil microbial life so the soils become self-sustaining. While these are a compromise with self-sufficiency they can be especially helpful when they incorporate necessary nutrient deficiencies, which are best determined by testing both soluble and total soil nutrients. In this fashion progress toward self-sufficiency can be made. After all, inputs that get us off the treadmill of future inputs are what we are looking for, no matter the scale of our operations.

Homemade Fertilizers: Sea Minerals & ORMEs

Unless one lives near the ocean, sea minerals may have to be brought in rather than being produced within the farm itself. This may be easier than one thinks, as sea minerals are a by-product of salt evaporation. Since supermarket buyers overwhelmingly prefer free running salt, most evaporators remove the sodium chloride out of the sea water leaving a pot liquor that is dense and almost oily — so much so that unless these salt works are marketing fully evaporated (aka macrobiotic) sea salt to the more knowledgeable chefs and health enthusiasts, these sea minerals are a waste product that can be obtained in bulk at reasonable prices. Used at rates from 1 to 5 liters per hectare per year, this bounty of the sea should never be wasted as it contains a well-balanced blend of almost every element in the periodic table. Moreover, it will contain ORMEs.

Orbitally Rearranged Mono-atomic Elements (ORMEs) occur when large numbers of atoms of various elements align their electron orbitals so they resonate as though they were single atoms, thus becoming superconductors and virtually weightless. Atomic physics has only begun to shed light on this ancient mystery in the last couple of decades even though allusions to these substances and their properties can be traced back into ancient civilizations.

It is now evident that many of the puzzling features of plants and animals clearly mimic the quantum behaviors of single atoms even though they are thought to involve astronomically huge collections of molecules.

How can photons impact a concentration of a billion or more chlorophyll molecules in a leaf and simultaneously go down all the pathways available to transfer their energy into making sugar, achieving virtual 100 percent efficiency? How can a solution of zinc sulfate be detected at the tip of a very tall tree almost the instant it is poured on the soil at the tree’s roots?

Living organisms exhibit behavior, on a gross level, once thought to exist only at the level of atomic particles. If large collections of atoms can re-arrange their electrons so they all resonate in perfect alignment — and evidence suggests they can — then theoretically they will behave as single atoms no matter how many atoms they once may have been individually. We see this sort of behavior with helium when we chill it close enough to absolute zero that all the electrons simultaneously share the same base state, but recent research indicates this can occur with elements as complex as gold, platinum and iridium.

Furthermore there are indications that seawater is rich in these substances, and ORME-rich extracts can be obtained by raising the pH of seawater to 10.78 using sodium or potassium hydroxide. This will result in a dense, white precipitate that can be separated from the original solution and used in agriculture with results that may be startling, especially with leguminous crops such as lucerne and soybeans.

Small quantities of ORMEs, on the order of about 200 grams per acre, are recommended per application with the understanding that this is experimental.

Homemade Fertilizers: Calcium Nitrate & Molasses

Lastly, here is another formula that is likely to require bringing in the ingredients in the short term to achieve long-term goals. This is useful when planting in areas where tall, woody annual weeds, such as thistles or amaranths, are prone to sprout prolifically. These weeds indicate imbalances of too much soluble potassium as compared to the available calcium in the soil. Shifting this balance over to favor calcium would encourage clovers and other calcium/protein-rich weeds such as daisies or nettles to take the place of the thistles and amaranths.

This can be done when sowing, or even after weed emergence if conditions are dry, by boom spraying 2-5 kilograms of calcium nitrate along with 2.6-4 gallons of molasses dissolved in 43 gallons or more of water per acre. This amounts to a low potency homeopathic dosage as there is hardly enough calcium nitrate to shake a stick at, and yet the balance tends to shift beautifully and shut down the weeds.

Many organic certification programs prohibit the use of calcium nitrate, and at rates of 75 to 250 kilograms per hectare this extremely salty fertilizer undeniably is badly overused. However, most organic programs allow a wide variety of trace minerals to be added at low levels in their soluble salt forms as long as soil and leaf tests indicate they are deficient. Such light applications of major nutrients as calcium nitrate are far too dilute to harm the soil biology and are only intended to give a slight adjustment to the calcium/potassium balance so favorable species are encouraged.

Editor’s Note: This article appeared in the April 2014 issue of Acres U.S.A.

About the Author

Hugh Lovel is an agricultural consultant serving clients in both the United States and Australia. He consults, speaks and teaches on all aspects of agriculture.

When Less is More: Understanding Fertilizer and Solubility

By Lawrence Mayhew

Make the gesture “just a little bit” by squeezing your thumb and index fingers as tight as you can; tighter, tighter — the amount of fertilizer you could hold between your fingers is about the amount dissolved in soil solution … per acre! That’s right; there is very little, if any, dissolved “plant food” in the water of a typical soil.

The amount of plant nutrients dissolved in soil solutions is so small that it is expressed as parts per million (ppm), not hundreds of pounds or tons per acre. While synthetic fertilizers are sold primarily on the basis of their water (aqueous) solubility, the emphasis on aqueous solubility is generally misunderstood and somewhat misguided.

It is generally known that over-application of extremely soluble synthetic fertilizers has been responsible for disrupting ecosystems and numerous environmental problems. What is not generally known is that all highly soluble soil inputs, including sulfates, chlorides and fluorides, disrupt the structure of water molecules, impeding the biochemical energy flows that affect the metabolism of plants, making them more susceptible to insect pressure and diseases and decreased water use efficiency.

It is also a well established fact that highly soluble phosphate fertilizers become “tied-up” soon after application. When there is an overabundance of dissolved phosphates in soil water, the soil system responds chemically by forming more stable forms of phosphorus, usually by chemically combining with calcium cations and complexing with lanthanides (rare earths) and organic matter. All of these materials can release phosphorus as plant nutrients through microbial activity.

Although water is critical to all life forms, there are numerous metabolic pathways in biological systems where it gets in the way and must be pushed aside; it’s called the hydrophobic effect.

The hydrophobic effect is responsible for the fluidity of organisms and the efficient energy flow through all biological systems, where enzymes, microbes, surface activities, and the thermodynamics of the energy available to do “work” (enthalpy) operate in environments where water is squeezed out, making hydrophobic interactions the most important life-sustaining processes, not aqueous solubility.

field to be fertilized
The amphiphilic nature of humic substances allows them to work in water and hydrophobic environments, providing the critical conditions necessary for biological processes when they are closely associated with clays.

The living organisms that provide plant nutrients through geomicrobiological interactions with insoluble soil colloids live in a universe of extremely low concentrations of dissolved nutrient ions in soil water, where some of the most critical steps in the processes of life proceed mainly in the intentional expulsion of water in the process of microbial adhesion to surfaces of soil materials. However, if there is an imbalance in the positive and negative ions dissolved in soil solution, the adhesion is disrupted.

In eco-agriculture, highly soluble fertilizers are either used sparingly or, as in the case of organic agriculture, they are banned or highly restricted. Regenerative agricultural practices use materials that are nearly insoluble in water, such as humates, compost and rock phosphates as interactive components of geological and microbiological processes that provide a balance of nutrients for plants. The role of carbon dioxide (CO2) in soil processes, which has the greatest impact on all soil processes and pH balance, is generally overlooked.

Fertilizer and Solubility: Soil Solution

The water associated with soils contains both dissolved chemicals and undissolved suspensions of colloidal substances. The portion of soil water containing dissolved substances is called the soil solution. Table 1 illustrates the amounts of common plant nutrients dissolved in soil solution. The concentrations of soil nutrients in the table are listed in millimoles (mmol) of dissolved material per liter (L-1) of water and parts per million (ppm). A millimole is 1/1000th of the molecular weight of a substance expressed in gram equivalent weight. For example, the molecular weight of nitrogen is 14, therefore 1 mmol of nitrogen would weigh 0.014 grams. A U.S. dime weighs about one gram.

Using the data for nitrogen in Table 1, the highest concentration of nitrogen reported was 0.46 mmol L-1 of soil water; that’s about 0.006 grams of dissolved N per liter of soil water. Assuming field moisture is about 15 percent (~0.9 inch ft-1) and assuming there is about 1 million pounds of soil in the upper 6 inches per acre, total dissolved nitrogen in soil solution at that depth would be approximately 1 pound in 1 acre. For dissolved phosphorus, the range would be 0.001 to 0.002 pounds in 1 acre!

The accuracy of these data can be questioned, and soil solution concentrations vary tremendously depending on soil types and their water holding capacity; nevertheless, astonishingly little if any dissolved nutrients exist in stable soil systems at any time other than when soluble fertilizers are applied.

Synthetic nitrogen, the most over-applied agricultural chemical, is not applied to improve the quality or fertility of soils; instead it is used primarily as a plant growth stimulant to increase yield. If the old adage that says it takes 1 to 1.25 pounds of nitrogen to grow 1 bushel of corn is true, and if there is only 1 pound of N in an entire acre of soil solution, where do the hundreds of pounds of nitrogen come from?

The answer is the numerous organic compounds produced by biological fixation of nitrogen from the atmosphere and carbon dioxide released by microbes. Look at any chart of the Nitrogen Cycle; you will see that numerous microbial interactions are part of the cycle supplying plant nitrogen needs, but the role of soil CO2 in that cycle is generally ignored.

As you are reading this article, you are breathing in almost 80 percent nitrogen — plants and soil microbes do the same thing, but instead of treating nitrogen like an inert unreactive chemical, soil microbes utilize it. Additionally, soils need to be well aerated because microbes require oxygen to convert atmospheric nitrogen to nitrates and ammonium. Soil microbes may be responsible for providing roughly 80 percent of all the soil nitrogen needs for all plants globally. However, soil compaction and overuse of nitrogen fertilizers are having such a negative impact on nitrogen-fixing microbes that the Earth is to the point where the total fixed nitrogen in contemporary soils is actually less than pre-industrial times. Soil compaction also impedes the transfer of CO2 from the atmosphere into soils and the movement of CO2 generated by soil microbes through the soil.

Hydrophobic Interactions

Conventional dogma considers the water of soils as a place to accommodate dissolved chemicals intended to be passively taken up by plant roots in the soil solution. Although this is true to some degree, overall the uptake of plant nutrients is a highly regulated complex process, especially when nutrient levels are low.

Hydrophobic conditions, where water is squeezed out, allow insoluble nutrients to pass through living membranes in a manner that utilizes the least amount of energy.

Biological membranes make use of enzymes, integrated membrane proteins and amphiphilic molecules such as humates to assist in the movement of nutrients through living membranes. Amphiphilic molecules have both hydrophobic (water shunning) and hydrophilic (water loving) domains in their molecular structure, making them very versatile. Humic substances, many proteins and almost all soil sulfur compounds are complex amphiphilic organic (carbon) substances. Because of these multidimensional interactions, where reliance on water solubility is thermodynamically counterproductive, the ability of microbes to adhere to surface structures of minerals is extremely important because only certain surfaces are recognized by microbes and their enzymes as compatible surfaces for attachment in the process of converting insoluble minerals into plant nutrients. It’s analogous to recognizing a hamburger as food compared to a cow pie; both are about the same color and made of carbon compounds, but you instinctively know the difference.

When soluble fertilizers are over-applied, only a small fraction remains “available” as plant nutrients because they are highly polarized ionic salts that combine with other soil chemicals and minerals. This so-called “tie-up” is actually the insoluble products of chemical reactions within soils to bring unstable chemicals into chemical equilibrium, reducing the toxic properties of soluble fertilizers.

Thermodynamically, these reactions cause energy flows to be more chaotic (entropy), where energy that would otherwise be available for “work” is diverted to stabilizing the system instead.

Eventually, all fertilizers will interact with soil microbial processes that release the tied-up nutrients. Microbial release is assisted primarily by organic matter, especially humic substances, that provide the proper conditions for these natural interactions.

Soil organic matter is the single most important component of soil systems. It is derived from the action of microbes and plant root exudates, providing conditions for the most efficient release of soil nutrients for plant uptake.

As many of you already know, soil colloids (e.g. clays and organic matter) carry an overall negative charge on their surfaces, which can be measured as cation exchange capacity (CEC).

However, many microbes that have to interact with soil colloids are also negatively charged. Their ability to adhere to like-charged soil surfaces seems contradictory because like charges repel, however due to their hydrophobicity, microbes overcome the charge repulsion through a physical force called van der Waals attraction, enabling certain bacteria to attach to mineral surfaces to extract food.

As a general rule, microbes that have plenty of nutrition also have the ability to adhere to surfaces better than microbes that are undernourished, and well-nourished bacteria demonstrate the highest degree of hydrophobic character.

Van der Waals attractive forces are extensively exploited in nature; the ability of spiders to “stick” upside down to a ceiling is a good example. Because van der Waals attractive forces are not electrostatic, meaning they have no charge, they are weak forces easily overcome by the presence of high concentrations of positively charged soil solution ions (cations) from soluble fertilizers, soluble soil amendments or soil acidity. An excess of any cation in the soil solution will cause a reduction in the hydrophobicity of these bacteria and the collapse of van der Waals forces, interfering with the process of bacterial surface adhesion.

Therefore, the bioavailability of nutrients is not totally dependent on water solubility, because in nature it would be far too inefficient to support life based solely on aqueous solubility. Nature works smart, not hard.

Carbon Dioxide to the Rescue

Soil acidification, where the measured soil pH is too low for efficient agronomic production, is the excess of hydrogen (H+) and aluminum (Al3+) cation activity in soil solution. It is typically caused by the overuse of high nitrogen inputs, especially urea and anhydrous ammonia because they dissolve stable soil organic matter.

The reduction of SOM reduces biological activity, which leads to a reduction in microbial CO2 production, increasing the chemical activity of aluminum (Al3+) and acids (H+). Al3+ and H+ take the place of magnesium (Mg2+) and calcium (Ca 2+) 2, 3 cations on clay and organic matter cation exchange sites, causing an imbalance in bioavailable nutrients.

The chemical activity of Al3+ and H+ needs to be controlled in all biological systems to avoid toxicity. The chemical control and balance of these cations is called buffering, where pH is maintained in a more desirable range.

It is generally accepted that humic substances, the most stable form of SOM, and clays, provide a great deal of buffering in soil solutions. However, the role of CO2 is generally overlooked nowadays. Soil-building activities are enhanced when buffered by CO2, one of the products of microbial activity.

The combination of CO2 and water is the first step from which all of the countless forms of organic matter are biologically synthesized in the process of making soil conditions fit for life.

In natural soil systems, the availability of nutrients is controlled by the biological release of organic acids (H+) that are balanced (buffered) by bicarbonates (HCO-) released from plant roots, which are balanced by the microbial release of CO2, which is in balance with soil calcium carbonate (calcite). Carbon dioxide released by microbes, in addition to the CO2 adsorbed from the atmosphere, converts rapidly to carbonic acid upon contact with soil water. Carbonic acid readily dissociates in water into acid H+ cations and anti-acid carbonate CO3 2- anions, counter balancing the acid H+. The rapid back and forth reactions of these ions has a powerful buffering effect on soil solution, helping to keep soil solutions in the range of 6.4 to 6.8 pH; a compatible range for a majority of plants and soil microorganisms.

Additionally, the alkalinity provided by CO2 and water as carbonic acid can move rapidly into the lower subsoil, whereas limestone has to be broken down by soil acidity and may take decades to move into subsoils.

As plant root mass increases, more organic acids are released by plant roots, such as carboxylic acids that increase the soil solution acidity to dissolve insoluble minerals, converting them into bioavailable nutrients.

Balance in pH is restored when carboxylic acids are rapidly consumed by microbes as sources of carbon-based energy, releasing CO2, which in turn produces carbonic acid that buffers the soil solution pH back to a more alkaline condition.

While microbes are dining on these energy-rich, carbon-based acids, they pull some of the geo-available calcium (Ca2+) out of soil solution, combine it with carbonate (CO3 2-) in soil solution making a particular crystalline form of calcium carbonate (CaCO3) called calcite. Calcite is a biomineralized calcium carbonate made by soil microbes that cycles through the whole soil system with the dual role of buffering agent and a bioavailable form of calcium.

Because plant root exudates provide multiple functions, it becomes apparent that plant root mass has a major impact on soil pH buffering, thus regulating the amount of H+ protons that are donated to negatively charged cation exchange (CEC) sites.

As more H+ is donated to the CEC sites, more Ca2+ and Mg2+ cations are released because H+ protons are preferentially adsorbed to CEC sites. The remaining bicarbonate anions participate in regulating the amount of cations released from CEC sites. The combinations of all of these chemicals in the soil solution in the presence of humates are widely recognized as charge-balancing mechanisms.

pH: CEC Balance

The amphiphilic nature of humic substances allows them to work in water and hydrophobic environments, providing the critical conditions necessary for biological processes when they are closely associated with clays.

Both humic substances and clays are water-insoluble soil components with powerful pH-buffering capacities and very high CEC, effectively driving fertility when dissolved nutrients in soil solution are at very low levels.

Because it is critical for soil bacteria to maintain hydrophobic conditions at the negatively charged soil colloidal surfaces, and as microbial hydrophobic conditions are influenced by both H+ hydrogen ion activity (pH) and nutrient cation activity in soil solution (CEC), it becomes apparent that the relationship between pH and CEC can be described as electro-charge balance.

The relationship of soil pH, CEC and soil CO2 was demonstrated many years ago (Figure 1). This balance appears to be critical to soil biological activity because the pH:CEC ratio is currently being used by some practitioners as another effective tool in regenerative crop production where biological activity, organic matter and biocompatible inputs are used to reduce the amounts of highly soluble inputs.

Editor’s note: This article appears in the October 2015 issue of Acres U.S.A.

Liquid Organic Matter Can Save Costs, Increase Yields

By M. Cano, P. Verdi & E. Liem

Organic matter improves tilling properties and increases soil water holding capacity in soil. It also makes nutrients in soil more readily available to plants as they leach through soil at minimum rates.

Most importantly, due to their unique chemical and physical compositions, organic matter-bound nutrients have been proven to be very efficiently utilized by plants. Organic matter is no doubt one of the most important key ingredients to increase soil productivity, which ultimately results in higher crop yields.

However, there are many types of organic matter with different methods of application, in which practicability and efficiency can be a concern. Canadian Humalite International Inc. of Edmonton, Alberta, Canada, has been making an effort to mitigate this challenge by utilizing low-quality coal (non-hazardous material, energy value around 7,000 BTU/lb) as a source of organic matter. This material is transported from the mine, crushed, liquefied, combined with nutrients, and then applied to soil and/or plants. Rather than using it as a non-efficient source of energy, this coal material is developed into products which are beneficial to soil.

The products are applied to soil/seeds, seedlings, and plants up to 15 percent flowering through drip irrigation and pivot/spray systems. Significant yield increases have been observed on various crops grown in different types of soil and climate regions in Canada and the United States. The following example is one of the most recent findings obtained from a field trial completed in Forrestburg, Alberta, Canada, in 2013.

Plants, when delivered liquid organic matter, have been proven to use less and make a higher yield

Soil in the area was loam with solonetzic clay underneath, degree of acidity (pH) = 6.1, electrical conductivity (EC) = 0.3 ds/m, and organic matter = 6.0%. It contained available macronutrients at 51 lbs nitrogen (N)/acre, 43 lbs phosphorus (P2O5)/acre, 631 lbs potassium (K2O)/acre, and 75 lbs sulfur (SO4)/acre. Available micronutrients were 0.8 ppm copper (Cu)/acre, 0.9 ppm boron (B)/acre, 4 ppm zinc (Zn)/acre, 21 ppm manganese (Mn)/acre, and 160 ppm iron (Fe)/acre. Nutrient analyses indicated that the soil was deficient in nitrogen, marginal in phosphorus and copper, adequate in boron and zinc, and optimum in other nutrients.

The field trial was completed at 27 outdoor test plots of 4½ feet x 22 feet (99 ft2) each (see Figure 1 above). Wheat of “Harvest” variety was planted in each plot in May. Macronutrients were applied on each plot during seeding at 60 N and 20 P2O5 lbs/acre. Micronutrients and liquefied organic matter were sprayed two weeks later on seedlings.

On each of the control plots, copper sulfate was sprayed at a rate of 0.10 lbs Cu/acre, iron sulfate at 0.55 lbs Fe/acre, and zinc chloride at 0.25 lbs Zn/acre. On each of the treated plots, a liquid product of Canadian Humalite International Inc. containing 1.5% liquefied organic matter was sprayed at a rate of 6 ounces/acre (or 2.55 g liquefied organic matter/acre) in combination with each micronutrient.

The micronutrient rates were 0.10 and 0.05 lbs Cu/acre, 0.55 and 0.28 lbs Fe/acre, and 0.25 and 0.13 lbs Zn/acre. Each control and treated plot was replicated three times. Harvest was made in September, in which yields from each replicate were averaged and recorded as bushel/acre (note: 1 bushel of wheat weighed 60 lbs).

It was found that crop yields increased from 64.7 to 65.3 lbs/acre (control) to 68.6 to 70.3 lbs/acre when liquefied organic matter was incorporated (see Figure 2 above). In comparison to control, zinc micronutrient experienced the lowest increase at 6.0%, while copper the most at 7.7%. Even when the micronutrient applications were reduced to approximately one-half (50%) of the original rates (control), yield increases were still observed at 67.7 to 68.3 lbs/acre when liquefied organic matter was incorporated. In comparison to control, iron micronutrient had the lowest increase at 2.8%, while zinc the highest at 6.0%.

Although detailed mechanisms were not investigated in this trial, it suggested that liquefied organic matter helped the plant to utilize the applied micronutrients more efficiently, resulting in higher crop yields. This would be great news for end users as they could enjoy a higher crop yield or a lower input cost while maintaining the same yield and reduced nutrient rates would also promote a healthier soil environment.

Most interestingly, the trial was completed in a relatively good quality of soil. Past experiences showed more dramatic results when similar crops were grown in poorer quality of soils (such as those with lower organic matter). In this case, the end users could reap a double benefit on the higher crop yield and reduced input cost.

In summary, liquefied organic matter did improve crop yields even at reduced nutrient rates.

Acknowledgments: Battle River Research Group of Forrestburg, Alberta, Canada completed the field trial. National Research Council of Canada (Industrial Research Assistant Program), Agriculture & Agri Food Canada (Canadian Agriculture Adaptation Program), and Canada Revenue Agency (Scientific Research & Experimental Development) provided financial supports and subsidies.

Editor’s Note: This article first published in the March 2014 issue of Acres U.S.A.

Cano (agronomy), P. Verdi (agronomy), and E. Liem (environmental, technical manager) are with Canadian Humalite International Inc., Edmonton, Alberta, Canada. For more information call 780-488-4810, email or visit

A Hack for Making Winter Manure

By Hubert J. Karreman, V.M.D.

Want to try an experiment with some pen manure or gut­ter manure (that’s not liquid)? I’ve read of a low-labor way of making compost by Trauger Groh, a biodynamic farmer in New Hampshire.

He does it this way:

  • Make a square pile of winter manure.
  • In May or June, split it into two windrows. Cover with black plastic and make holes on the top so it can breathe. Do not touch it anymore until it is ready for use the following year. Use it the next spring as a fully-finished compost.

Covering is critical because you don’t want it to be too wet. Manure with more than 70 percent moisture cannot build humus. Piles are 6-feet high fresh, made with straw/hay manure, and go down a foot or so as they age. They don’t use woodchips or sawdust, but if they did they would only need a little longer composting depending on size of woodchips.

Source: Four-Seasons Cattle Care

Adding Organic Manure to Your Crops

By Neal Kinsey

Manures are an excellent source of nitrogen. I work with farmers, who use a lot of manures in some areas, and I have other areas under consultation where there is no livestock for thousands and thousands of acres, and nothing organic is applied. A real saving factor in my area has been a broiler production facility that generates more than 30,000 tons of manure a year. Most of it is moved out to farmers.

Most of the farmers in southeast Missouri didn’t consider the value of manures when I settled in the area. It was generally not available to those who had gone out of the livestock business. In time some of us sat down and worked out some figures. One farmer tried it on 400 acres and another one tried it on a few less acres. Now the man who contracts for disposal of the manure has no trouble at all finding someone who wants it. In fact, my clients want it all if the quality is good.

Several items merit front burner consideration when applying manures. Number one, even the same type of manure can vary greatly in terms of fertilizer value, and the nutrient content will vary from fall to spring, depending on contents of the feed. Manures can be nutrient rich. Once you know what the total nitrogen content is, divide by two to compute the nitrogen potential for the next crop.

organic manure added to a field
A sprayer adds liquid manure to a field.

There are tremendous differences between poultry, cow and hog manures, and there is even a difference between layer and broiler manure. Layers are fed extra calcium to strengthen the eggshells. Broilers generally do not get this ration.

One client had 26,000 layers and farmed 160 acres. He had his soils analyzed because his fields weren’t producing good crops any longer. He had put so much layer manure on his farm and pushed the calcium level so high, it started tying up all his trace minerals. He was destroying his farm with the manure. It took about five years to get that problem solved because he didn’t choose to buy sulfur for remedial application.

Manures will drive calcium out of the soil except where cal­cium is highly supplemented, such as for egg production. The problem is that magnesium will take the calcium’s place. The farm mentioned above didn’t have excessive magnesium. In fact, it had basically the kind of magnesium levels needed. By the time we got finished with the switch, both were a little on the high side, but not extreme. When the calcium got high, it tied up his iron and certain other trace elements. This was what kept hurting his crops.

Every soil is different. You have to analyze what is going to happen to the several nutrients. When you analyze soils, you have to remember that just because a certain program works on one farm, that doesn’t mean it is going to work on the farm down the road. Every time the numbers change, a new set of circumstances come into view, with a new set of possibilities and potential problems.

If you use manure and it reduces calcium, but magnesium goes too high, in the end if the proper nutrient balance is to be achieved, you will likely have to use some sulfur to get magne­sium down to a reasonable point. So growers might as well start with sulfur in the first place, but be careful if calcium levels are low and magnesium levels are high. This inventory of facts should prompt us to remember that manure will take out some calcium. Manures will supply extra nitrogen, phosphate and potash to be certain, and is always a better source than physical measurements suggest. Nevertheless, an analysis gets you into the ballpark.

Source: Hands-On Agronomy