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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.