Farmers spend a lot of money trying to correct what they can see above the ground. Leaf colour changes, growth stalls, yields drop, crops show stress and nutrient deficiencies appear. The usual response is to add something: more nitrogen, more phosphorus, another trace element, another foliar feed, another stimulant.
But the crop above ground is often telling you what happened around the roots weeks or months earlier.
That root zone is where the plant meets the soil, and it is far more complex than the old model of roots simply taking up dissolved fertiliser. Around every active root sits a narrow living zone called the rhizosphere, and within those few millimetres, plants, bacteria, fungi, water, minerals, root hairs and organic compounds are interacting constantly.
The plant is not a passive passenger in this process. It actively changes the soil around its roots.
Plants release sugars, amino acids, organic acids and other carbon compounds into the root zone. They also produce a natural gel called mucilage, which helps roots move through soil, keeps contact between roots and soil particles and helps retain moisture around the root surface.
That mucilage also becomes part of the habitat in which microorganisms live.
Bacteria colonise the root surface and the material around it. Fungi extend fine threads through soil spaces that roots cannot reach. Microbes produce sticky compounds of their own. Soil particles become bound to roots and to one another. Over time, the immediate soil around the root becomes physically and biologically different from the soil only a short distance away.
This is not theory dreamed up by the biological farming industry. It is well-established plant and soil science.
Researchers have described plant mucilage as part of the matrix in which microbial biofilms can develop around roots. A biofilm is simply a community of microorganisms living together in a hydrated, sticky environment. Instead of imagining bacteria as individual organisms floating around in soil water, it is more useful to picture a living layer around the root where plant compounds and microbial compounds meet.
This matters because nutrient availability is not simply a question of how much nutrient is present in the soil.
A soil can contain considerable quantities of phosphorus, calcium, potassium, iron and trace elements and still produce plants showing deficiencies. The issue is often not absence, but availability.
Minerals exist in different chemical forms. Some are readily accessible to plants, others are bound within clay, organic matter or mineral structures. Biology is one of the mechanisms that changes those forms.
Microorganisms produce organic acids, enzymes and other compounds that alter conditions around the root. They participate in nitrogen cycling, phosphorus mobilisation, sulfur transformations, decomposition and mineral interactions. Mycorrhizal fungi extend the reach of the root system into parts of the soil the root itself cannot physically explore.
This is why a fertiliser analysis can tell you what is in a product, but it cannot tell you whether the biology around the root is functioning.
Fertiliser can supply nutrients. It cannot replace the organisms that cycle them. And only stable functional living soil microbes do that job.
There is another structure farmers may already have seen without knowing its name. Pull up a vigorous plant and sometimes the soil stays closely attached around the finer roots instead of falling away immediately.
That soil-bound root zone is called the rhizosheath. A rhizosheath forms through the combined action of root hairs, mucilage, microorganisms, fungal threads, soil particles and water. Research has found rhizosheath soil can differ significantly from the surrounding soil in moisture, organic carbon and microbial activity.
That should matter to anyone farming through dry conditions.
Plants have to maintain contact with water in the soil for as long as possible. When soil dries and pulls away from roots, water movement becomes more difficult. The biological and physical structure around the root can help maintain that connection.
This is also why soil structure and soil biology cannot be separated as neatly as agriculture sometimes tries to separate them.
Farmers know the feel of soil that is working. It breaks apart differently. Water moves into it differently. Roots travel through it differently. Machinery behaves differently over it.
Microorganisms contribute to that structure by producing compounds that help bind fine particles into aggregates. Fungal hyphae physically extend through the soil. Roots create channels. Organic material feeds the biology. Carbon moves through the system. Air and water occupy the pore spaces that develop between stable aggregates.
None of this means biology operates independently of rainfall, compaction, soil chemistry, salinity, machinery or management. It doesn't.
But treating soil as chemistry alone leaves out the workforce that makes much of that chemistry useful to the plant. This is where Earthfood comes in.
Earthfood was never to become another fertiliser. There are already thousands of those.
Earthfood exists because the soil needs living soil organisms capable of doing the biological work that fertiliser cannot do.
Earthfood Life is a certified organic living soil microbial system containing soil-borne microorganisms designed to establish and function in the root zone.
Their role is not to provide another short burst of soluble nutrition. Their role is to participate in the soil processes plants evolved with: nutrient cycling, mineral interaction, soil aggregation, carbon cycling and rhizosphere function.
"That is why Earthfood should not be judged as though it were seaweed, fish hydrolysate, humic acid, compost tea, worm juice or another liquid fertiliser. It is completely different and one of a kind". Bronwyn Holm, Founder, Earthfood.
Those products may provide nutrients, carbon, minerals or stimulatory compounds. Earthfood supplies the living organisms doing the work.
Once you understand that difference, the whole argument changes. The question is no longer simply, “What can I put on the crop?”
It becomes, “What is happening around the roots, and does the biology there still work?” This is also why we say water is the carrier, soil is the home.
We dilute Earthfood in water (1:60) because water is how we distribute the organisms across the paddock. The water is not the product and the microbes are not intended to remain floating around in a tank. They are not waterborne microbes.
Their destination is the soil.
Once there, the plant begins contributing its side of the relationship. Roots release carbon compounds. Microbial populations interact with those compounds. Minerals move through biological and chemical pathways. Soil particles aggregate. Root systems explore more of the profile.
That is the system Earthfood was built to support. It is not magic and we have never needed it to be.
Biology still has to deal with the realities of farming. Severe compaction matters. Waterlogging matters. Salinity matters. Chemical residues matter. Moisture matters. Temperature matters. Plant cover matters.
But there is an enormous difference between farming those conditions with a functioning biological workforce and farming them without one.
Farmers can often see that difference with a shovel long before they see it on a laboratory report.
Pull up a plant and look at the roots. Look at how many fine roots are present, how deep they are travelling, whether soil is attached around them, whether the profile is crumbly or massive, whether water is moving into the ground and whether roots are exploring the soil or fighting it.
The crop above ground is the result. Much of the work began underneath it.
Modern agriculture became very good at supplying nutrients, but we became less interested in the biology that makes those nutrients available, moves them through the soil and connects them with the plant.
That is the missing piece. Earthfood, as commercially available for over 40 years, is to put these microbes back and for humankind to walk away so they can do their job. They will perform and do that magnificently but we must return to the time when Mother Nature looked after the lot.
Research behind this article
Nazari et al. (2022)
Biogels in Soils: Plant Mucilage as a Biofilm Matrix That Shapes the Rhizosphere Microbial Habitat.
Frontiers in Plant Science.
DOI: 10.3389/fpls.2021.798992
Philippot et al. (2013)
Going back to the roots: the microbial ecology of the rhizosphere.
Nature Reviews Microbiology 11:789–799.
DOI: 10.1038/nrmicro3109
Danhorn & Fuqua (2007)
Biofilm Formation by Plant-Associated Bacteria.
Annual Review of Microbiology 61:401–422.
DOI: 10.1146/annurev.micro.61.080706.093316
Bonfante & Anca (2009)
Plants, Mycorrhizal Fungi, and Bacteria: A Network of Interactions.
Annual Review of Microbiology 63:363–383.
DOI: 10.1146/annurev.micro.091208.073504
Aslam et al. (2022)
Rhizosheath: An adaptive root trait to improve plant tolerance to phosphorus and water deficits?
Plant, Cell & Environment 45:2861–2874.
DOI: 10.1111/pce.14395
Geoderma (2023)
Rhizosheath: Distinct features and environmental functions.
Geoderma 435:116500.
DOI: 10.1016/j.geoderma.2023.116500
Bronwyn Holm, Founder, Earthfood®
Farmers' Friend • Gardeners' Guide • Soil Advocate • Growers' Voice