Living Soils A - Z

With acknowledgment to Dr Elaine Ingham.



Humic AcidsHumic acids are complex, highly condensed organic matter, with a high molecular weight which results in a deep, rich dark brown colour to these products.

Depending on the exact structure of the molecules humic acids bind salts, heavy metals, toxics, pesticides, and a variety of other reactive or ionic materials. Estimates have been made that each 1g of humic acid material can tie-up 1mg of ionic material. This means that the toxic material is no longer plant available. The benefit of having complex, highly condensed organic matter is readily apparent. The amount of humic acid material and thus the ability of that material to bind ions depends on the original source of plant material.

Typically humic acids are extracted with very strong acids and bases from leonardite, which is soft, brown coal. These strong acids and bases have to be neutralised before addition of the micro-organisms, or the acids and bases will harm the organisms. In addition, the humics extracted are denatured by the acid base reflux used, and thus the best products for growing microbes re-nature the humic acids before use.

If the pH of the product is very acidic or basic, the material needs to be brought to neutral pH before use. If pH is not adjusted, then the organic material will need processing by microbes before benefit will be apparent.

Fungi do the most work in the condensation processes of building highly complex materials like humic acid, although microarthropods, earthworms, protozoa and bacteria are also needed for full diversity of good humic materials.

As fungi decompose humic acids, they release simpler compounds, so of which are bacterial foods. Thus most humics have both a fungal and a bacterial growth response.

Fulvic Acids: Less complex, and of lower molecular weight, as compared to humic acids, but more complex than other organic compounds. Fulvics are honey to tan in colour. More bacteria are able to use these condensed materials than humic acids, although fungi are still strongly favoured by a true fulvic acid material.


AerobeAn organism requiring atmospheric concentrations of molecular oxygen as the final acceptor in metabolism.

AnaerobeAn organism requiring reduced oxygen concentrations, or elevated carbon dioxide concentrations in rider to be able to perform metabolic processes. Strict anaerobes typically are killed by even the slightest oxygen concentrations, while facultative anaerobes can function in both aerobic and anaerobic conditions, but use very different metabolic pathways depending on oxygen concentration.




Bacteria: Unicellular micro organisms, occurring in many forms, existing either as free-living organisms or as parasites, with a broad range of biochemical, often pathogenic properties. Bacteria also have an important role in decomposing organic matter, nutrient retention, disease suppression and building soil structure through the formation of micro-aggregates. Particular types of bacteria can undertake a range of other functions including the degradation of toxic compounds and nitrogen fixation.

Beneficial organismsNon-pathogenic life - often improving the growth of a desired organism in a more-or-less mutualistic association where both organisms benefit from the presence of the other.




BioActive Compost: BioActive compost has high levels of beneficial living microbes at proven quality standards. BioActive compost is used for starting a compost tea brew, or to apply directly to the soil. 

BioActive Compost Tea: Actively aerated compost teacontains all the soluble nutrients extracted from the compost, but also contains all the species of bacteria, fungi, protozoa and nematodes in the compost. Making sure only beneficial species are present in the compost is therefore critical. Good, aerobic compost contains a huge diversity of organisms. 

BioActive Compost Tea Brewer: The BioActive Compost Tea Brewer is an Australian designed and made 1000 litre compost tea brewer. This compost tea brewer has been quality tested by the SFI institute to ensure it provides high qulality and consisted BioActice compost tea, when used as directed. 




Complexity: means number of species and the number of different kinds of species in the soil.

Compost: is the aerobically decomposed remnants of organic materials. (see also BioActive compost).

Compost moisture meter/s: supplies a wide range fo the best quality REOTEMP compost moisture meters - used for measuring relative moisture content in compost piles/windrows and soils. See compost moisture meters.

Compost teaAccording to Dr Elaine Ingham, "The simplest definition of compost tea is a water extract of compost that is brewed, or in other words, the organisms extracted from the compost, the bacteria, fungi, protozoa and nematodes, were given a chance to increase in number and activity using the soluble food resources and nutrients present in the liquid. An enormous diversity of bacteria, fungi, protozoa and nematodes should be present, depending on the quality of the compost. It is usually made over a 24-hour cycle for optimum extraction and diversity…It is not manure tea, bacterial tea or leachates. Real actively aerated compost tea does not contain human pathogens." (from the Compost Tea Brewing Manual, 5th Ed., page 1).

Compost tea brewing: Compost tea is a brewed water extract of compost that contains all the soluble nutrients, bacteria, fungi, protozoa and nematodes from the compost it is brewed with. Production methods include completely aerobic  - (actively aerated compost tea - AACT), using fermentative selective conditions (fermented compost tea - FCT), using long term brewing conditions where the tea returns to aerobic conditions after several weeks, as the smell goes away (long brew compost tea - LBCT), or using truly anaerobic conditions (non aerobic compost tea - NACT). A true compost tea should contain ALL of the organisms that are present in the compost. Loss of the aerobic groups when FCT, LBCT or NACT are made leaves it questionable whether these products should even be called compost tea. They lack a large component of the biology needed to obtain the benefits that are possible from compost or compost tea. 
(see also
 BioActive compost tea)

Compost thermometer/s: supplies a wide range fo the best quality REOTEMP compost thermometers - used for measuring compost and soil temperature. See compost thermometers.


DecompositionThe process of conversion of organic material from one form to another, generally with biomass production by the organism doing the decomposition, production of metabolic waste products and carbon dioxide.

Disease Suppression: The ability to inhibit, compete with, or consume disease-causing organisms preventing them from causing disease.



Exudates: Simple sugars, proteins, carbohydrates, hormones released by plants into the environment, typically for the express purpose of encouraging the growth of bacteria and fungi which for a biological shield around the plant, preventing disease-causing organisms from detecting the root.



Facultative AnaerobeOrganisms that can perform metabolism using either oxygen or inorganic molecules as the final electron acceptor in metabolism. These organisms generally switch from aerobic to anaerobic metabolism at low oxygen concentrations.

Fermentation: A specific group decomposition process that typically involves the production of carbon dioxide, Both aerobic and anaerobic processes can be included as fermentative process, although usually this term refers to anaerobic fermentation where alcohol is produced. Wine or beer fermentation, for example.

Foliar foodweb: The foliar foodweb is the set of organisms, similar to the soil foodweb, on the foliage of your plant.  The plant leaf, blossoms, stems, etc. release exudates, just like the roots, to feed these organisms and keep a protective layer around the plant so disease can’t attack, and nutrients will be cycled correctly for the plant.


Different fish contain very different amounts and types of oils, proteins, bone, and cartilage. Recognise that fish from contaminated waters will be high in that contaminant. Read the Fish Product labels carefully to determine content, as knowledge of too-high levels of heavy metals or inorganic salts will be revealed there.

Knowledge of the level of these chemicals in your soil is necessary in order to know if the addition of a great deal, a little or no mineral would be beneficial to the plants being grown. Data are needed to know how much can be added safely or how much needs to be added to the soil.

As with so much in life, there is a Goldilocks principle in all of this, enough but not too much is what is required. You need to know how much can be added, or how much needs to be added, in order to determine the amount of any of these products from a chemical point of view.

Fish hydrolysateFish hydrolysate, in its simplest form, is basically ground up fish carcasses. After the fish fillets are removed for human consumption, the remaining fish body, (which means the guts, bones, cartilage, scales, meat, etc.), is put into water and ground up. Some fish hydrolysate is ground more finely than others so more bone material is able to remain suspended. Alternatively, enzymes may be used to solubilise bones, scale and meat. If the larger chunks of bone and scales are screened out, calcium or protein, or mineral content may suffer. Look at the label carefully for the concentration of mineral elements in the liquid.Some fish hydrolysates have been made into a dried product, but most of the oil is left behind in this process, which means a great deal of the fungal-food component would be lacking.

Fish Emulsion: If fish hydrolysate is heated, the oils and certain proteins can be more easily removed to be sold in purified forms. The complex protein, carbohydrate and fats in the fish material are denatured, which means they are broken down into less complex foods. Over-heating can result in destruction of the material as a food to grow beneficial organisms. Once the oils are removed and proteins denatured and simplified by the heating process, this material is called a fish emulsion. How much heating? How much of the fungal food was removed? Testing is needed to determine what organisms the product will select for growth.

Fish Oils: Fish oils, removed when fish hydrolysate is heated to a high enough temperature to drive the oil to the surface, typically are fungal foods. The Carbon:Nitrogen ratio (C:N) of oil is generally wide enough to limit the bacterial response, although contamination with denatured protein from over-heated fish can result in a bacterial response. Both bacterial and fungal growth could be desirable in certain instances, while strictly fungal growth would be desired in other cases. A simple way to assess how much damage to the complex organic structure occurred during processing (cooking and purifying steps) is to determine how well beneficial fungi grow in the material before versus after processing.

Dry Fish Products: Hydrolysates and emulsions can be dried. But many of the complex oils, fats and structurally complex proteins are lost. All dried fish materials need to be tested to determine whether fungal foods are still present after drying.

Fungi: Plants of the division Thallophyta, lacking chlorophyll, ranging in form from a single cell to a body mass of branched filamentous hyphae that often produce specialised fruiting bodies and including the yeasts, moulds, smuts, and mushrooms. 

Fungi comprises of microscopic cells that grow in long threads called hyphae. Fungal hyphae bind soil particles into macro-aggregates which increases the water-holding capacity of soils and infiltration. Fungi also have an important role in the decomposing organic matter into useful forms, nutrient retention, and disease suppression.
see also VAM)

Mycorrhizal Fungi: see VAM

FoodwebThe set of organism relationships, often based on who-eats–who, or which organisms cycle a particular nutrient within and ecological community.




Humics: The mixture of all recalcitrant, long-turnover time organic compounds in soil, includes both fulvic and humic fractions.

Humic Acidsee 'Acids'




Plant material from dried kelp: Kelp contains mineral components normally found in the proper balance for plants growth, in chelated forms. (Also available as Kelp Powder).

If harvested green and rapidly dried, the product will contain bacterial foods in the form of simple sugars and proteins, and fungal foods such as cellulose and wide C:N materials. If harvested after the plant sets seed or goes dormant, then only the fungal foods are normally present. Kelp also serves as a surface for fungi and bacteria to grow on (as does any particulate material).

Different kelps contain different mineral nutrients in varying ratios depending on water quality. Chemical analysis should be available from the seller so the proper choices can be made to return the missing mineral components. Use the kelp which supplies the lacking nutrient in high enough concentration to make a difference, depending on what you need in your soil. The addition will need to be to the soluble pool if soil lacks the proper biology. To the exchangeable pool if the nutrient cycling sets of organisms are present. Possibly no addition may be required if the mineral rock material contains plenty AND the proper biology is present and functioning.

Determination of what is chemically missing requires soil chemistry assessment. If no biology is present, then the soluble soil chemistry pool must be amended, since that will be the only pool available for plant uptake. If biology is present, then an Albrecht, or exchangeable pool assessment can be used, since there will be organisms to do nutrient cycling into plant available forms.

Different kelp species are known to contain very different sets of bacterial or fungal foods. They may contain an innoculum of bacteria and yeast which are adapted for marine habitats, not soil. Highly salty soils may have the same microbes, so in high EC soils, the biology needed can be enhanced. Most soils are not that salty. However some benefits have been observed by adding the species of salt-tolerant, and salt-utilising microbes that could only have come from the kelp.

Thus kelp can be a very versatile product, supplying bacterial and fungal foods as well as the missing nutrients, if it is harvested, washed, and processed carefully with any eye to preserving all these potential benefits. A careful assessment of what each kelp product can do to the biology and well as what it might fix chemically is required.



Effective Microorganisms (EM): Effective Micro-organisms were isolated from traditional ferments of vegetable materials, such as cabbage and kitchen waste (bokashi). The main organisms typically found in EM are (1) Lactobacillus (about 6 to 8 species), (2) actinobacteria (as low as one to as many as 20 species), (3) purple, non-sulphur photosynthetic cyanobacteria (typically only 1 species, although at times 2 to 3 have been observed) and (4) many, many different types of yeasts, which are the fungi that can grow in facultative anaerobic conditions.

All of the organisms in EM are facultative anaerobes. Their observed benefits in soil, compost or tea are that they produce copious quantities sticky material, which can result in rapid aggregation and ability to stick to surfaces. Organic acids which may help stabilise pH if soil is too alkaline are also made in high concentrations but are not the lower pH, much nastier acids made by non-beneficial species of bacteria and yeasts which grow in more classically anaerobic conditions.

Mother Cultures: Obtained from distributors of EM and should contain Lactobacillus, Cyanobacteria, actinobacteria and yeasts in high diversity. Guarantee of minimum numbers of each bacterial and yeast species should be given when buying this product.

Activated EM: Fermented culture made from the mother culture and thus depends on the plant material or other foods added into the fermentation. Again, guarantee of the set of organisms in the activated mix should be given at time of sale of the product.


Any additive to soil, compost or compost tea should be in an organic or chelated form. Chelation means, in a practical sense, complexed with a protein. Another way to think of this is that an ionic form has been complexed with an organic molecule.

Addition of any salt (ionic or inorganic forms are salt forms) has the potential to harm the biology through osmotic effects, so inorganic additions to soil, compost or compost tea should be avoided to the greatest degree possible. Complexing salts with organic matter solves this negative effect.

Calcium additions: Calcium has been added to soil for a long time, as far back as humanity has written down records of agricultural practices, calcium in the form of bones and rock powders have been used. Chelated calcium has shown to be much more beneficial to biology than adding the salt forms of calcium, or indeed, any other nutrient. Each formulation enhances different sets of organisms, so data are required to know what will benefit with each product.

Calcium Carbonate: Also known as lime, which is a salt or inorganic form of calcium. This will alter the pH of anything to which this is added, and by taking up available hydrogen, will cause pH to raise. The loss of available water and the sudden pH shift can be extremely detrimental to organisms.

Calcium sulphate: Also known as gypsum, an inorganic form of calcium and sulphur. This is a salt (disassociates in water, and thus reduces useable water). When sulphate is released, the impact on organisms can be extremely detrimental. Typically the greatest impact is on the beneficial soil fungi. Plate count methods of assessing this impact are extremely mis-leading, as beneficial fungi dont grow in lab conditions on plate media and thus the loss of the important soil fungi is missed when sulfate is released.

Dolomite: A salt of calcium and magnesium. Historically used as a source of calcium but contains more magnesium than calcium, and results in even more rapid soil structure collapse after addition. Albrecht clearly showed that montmorillinite clay structure collapses when the ratio of calcium to magnesium drops below 6. Addition of a material that contains more magnesium than calcium drives the balance towards compaction, loss of nutrients from the soil, and if used long enough, will result in the need to use pesticides. If soil lacks magnesium, the better choice is to use kelp containing high levels of magnesium rather than adding dolomite.

Epsom salts: A salt form of magnesium and sulphate. Often used to leach calcium out of soil and increase magnesium levels. Except there is no way to leach just one compound without also leaching many other nutrients. In addition, the sulphate has quite negative impacts on microorganisms, especially soil fungi. Don't be mislead by plate count studies showing no impact on soil fungi in plate methods.  These methods are incapable of growing 99.9% or more of the fungi actually in soil, and especially miss the beneficial species. The better choice is a chelated calcium, or kelp.


Bacteria grow well and rapidly on simple sugars to exclusion of any fungus, until sugar concentration becomes extremely high. The simple preservative effect with molasses is the high concentration of sugar. Most organisms cannot grow in the high concentration of sugar. Once a container of molasses is sealed, however, condensate can form on the under-side of the lid if the container suffers heating cooling cycles. As the water drips into the top layer of the molasses concentrate, the sugar content can be diluted enough to allow fungal or actinobacterial growth as a surface scum. Just skim off the surface scum before use in soil, compost, or tea. Do not feed to animals or humans after a surface scum has formed unless you can recognise the organism as non-harmful.

Addition of foods that cause rapid bacterial growth can tie-up nitrate nitrogen so fast, and so effectively that plant growth can be harmed, and even stopped. Bacteria win in competition with plants for N in soil, and thus plants can be killed as the result of lack of N. Of course, the solution to this problem is NOT to kill the bacteria, but rather to establish normal nutrient cycling processes once again. How? Get the protozoa and bacterial-feeding nematodes back to work!

Non-sulphured, Black-strap Molasses: Contains no preservative other than the high concentration of sugar. Black-strap molasses contains about 150 different kinds of sugars, from simple to somewhat complex to humics. During the extraction of sugar, heating results in condensation of the sugars into humic-like substances. The majority of foods in molasses are bacterial foods, but a few are fungal foods. Fungi tolerate high concentrations of sugar better than bacteria, so extremely high concentrations of molasses favour fungi. Testing must be performed to assess what concentration is needed to select for fungi and against bacteria in any particular set of conditions. Testing is also needed when using as a nitrate-to-bacterial biomass converter.

Weed control is often STARTED with addition of molasses to tie-up the excess nitrate helping to set the stage in the soil to grow weeds, and not the plants you want to grow. Assess the calcium situation as well, however, because if you add molasses to grow lots of bacteria, and your soil has poor structure, you may just drive the soil into reduced oxygen conditions, which can result in plant death as well.

Organic Molasses: No strong acids or bases, nor extremely high heat are allowed in the production of organic molasses. No preservatives can be used. Because of the lower temperatures used, less condensation of the sugars occur, so fewer condensed, humic materials are present compared to non-sulphured, black-strap molasses

Feed Grade Molasses: Commercial grade molasses has sulphur and possibly other preservatives and antibiotics added to reduce fungal growth. Sulphur in most inorganic forms make excellent fungal inhibitors. Antibiotics will inhibit, kill and prevent the growth a wide range, but not all bacteria and fungi. Thus feed grade molasses is not a good choice for a biological stimulant. Care must be taken to read about the ingredients so no ugly little surprises confront you and you don't get the response you want to see.

Mycorrhizal Fungi: (see VAM)


Nematodes: Any of various worms of the phylum Nematode having unsegmented thread-like bodies. Nematodes are classified into four different functional groups depending on their food source (fungal, bacterial, or root feeders. There are also predatory nematodes that eat other nematodes). Most nematodes are beneficial, forming an integral part of the soil food web. They convert nutrients into plant available forms by consuming either fungi or bacteria. Beneficial nematodes also consume disease causing organisms, and are an important food source for larger organisms. The presence of root feeding nematodes in high numbers is an indication that the soil food web is in a degraded state.

Nutrient Cycling: The process of conversion of organic and inorganic material form one form to another, generally with the production of biomass by the organism doing the cycling. Production of metabolic waste products which serve as the next step in the nutrient cycle, and carbon dioxide.