Clay soil

What I’m about to write will not help you farm according to the Elementary Farming approach. Nevertheless, I have decided to take on this discussion in order to defend clay soil, which is wrongly unappreciated by most.

This topic should be set against the backdrop of the legitimacy or otherwise of what is dictated by institutional science. The scientific approach of western society has created problems that it has always failed to prove itself capable of solving. The scientific and notional hot-iron branding that is imposed on us from our first educational experience generates a conviction in us, suggesting that there is indisputable evidence upon which any potential further reflection should be based. And yet, all you have to do is look to the past to observe how “official” science, in every field of application, is constantly looking for remedies for the mistakes of the previous generation. We could define this kind of science a process of materialistic degeneration of intuition and perception, powers provided by nature, which are enough to ensure that every living person maintains their consonance with reality. Official agronomy (which is also an applied science but not an integrated one, where the disciplines involved do not communicate sufficiently with one another, and which is the most conservative when it comes to innovation too) takes into account the mechanical, chemical and physical aspects rather than the vital energy of the soil. It is a materialistic vision in which soils are seen as non-living bodies. The soil studied in agronomy is a fixed theoretical model that doesn’t exist in a reality made up of evolving processes, which are required to keep it alive and fertile over time. For this reason, I believe that the geological nature of a soil has no bearing on the formation of humus and, therefore, on its fertility once it is “mature”.

In a favourable environmental context, the human body and the earth are independent when it comes to keeping themselves healthy. That is to say that they do not require any “specialist” intervention.

Vegetation can find all the sustenance it needs in nature only if the soil unites mineral and organic components, even with extreme variations in the balancing of the two elements. A soil where these coexist in a dynamic equilibrium can be defined “humus” or, more simply, fertile. “Conventional” agricultural practices kill the living part of the soil, reducing it to an inert substrate.

Clay soil

Pure clay has been used in the production of artefacts for thousands of years. However, to become agricultural soil, it must encounter other grain sizes during its geological evolution (forming the so-called “mixture”) and, above all, it must combine with organic matter. As with peat, tuff, loam and sand, clay is classified according to the size of the granules of which it consists. Clay granules are the smallest of all, and this characteristic becomes a positive (when the clay is respected) and a negative (when the clay is worked). In fact, when we call a soil “clayey”, we are only referring to the prevalence of clay over other components.

Arable land is the result of the parent rock and the organic litter breaking down. In both cases, this occurs due to physical phenomena and the activity of multiple life forms. These life forms find their nutrients by extracting potassium, phosphorus, sulphur, calcium and magnesium, in particular, from the rock and the litter through acid processes, and releasing silicon, iron and aluminium, in particular, into the soil to the extent that the roots of the plants only take up a minimal portion. The accumulation of the latter elements in the soil is what causes their crystallisation (in chemical terms: they precipitate) or, rather, the formation of clay soils in all their specific variations.

When we talk about clay in farming as a synonym for “hard” soil, which may crack in the absence of moisture or become muddy when wet, we are actually referring to the state in which human activity has reduced the mixture to a prevalence of clay, removing the organic component through agricultural practices or preventing its formation and consequently destructuring the mineral part. In different forms, subterranean life resides in both the mineral component and the mineralised, inert, organic component. But it is in the harmony between these two factors that soil can emerge from a state of inertia, activating its vital potential, which nature has given it, to the point of saturation. A fertile soil is, therefore, the result of an equilibrium between mineral and organic components. However, to expand on this, we need to introduce the “colloidal state” concept. Due to its granulometric fineness, clay presents the minerals of which it is composed in a specific form of aggregation known as a “colloid”. Even the organic matter collects in a colloidal state, and this common condition makes the natural process of combining these two, seemingly incompatible, organic and mineral worlds possible.

Both in the mineral and the organic part of the soil, the colloids have a negatively charged valence and would, therefore, tend to repel one another. However, due to the colloidal ability to disperse in water, they manage to coexist in the presence of this molecule. In fact, in H2O, the electrons are more attracted to the oxygen nucleus than to the two hydrogen nuclei. In this way, one of the molecule’s positive poles remains free and can hold on to the mineral and organic colloids, which, as mentioned, have a negative valence.

The reason why colloids are not dragged away by the flow of rainwater, which is almost distilled in nature, is that the soil also has electropositive minerals in its composition (such as Ca, Fe, Mg and Al), which are able to retain electronegative organic and mineral colloids from erosion. The effect of irrigation water is different. Since it does not come from the sky but from the earth, irrigation water also contains elements with positively charged valences, which are capable of “hooking” the mineral and organic colloids in the soil, and dragging the colloids away with them in a runoff phenomenon. This is why irrigation is as harmful as working, weeding, fertilising and amending the soil. Moreover, in the clay and humus mixture, the roots of the plants do not take up runoff irrigation water but, instead, physiological liquids produced by the metabolism of the overall living organic fraction of the humus. If we consider the true nature of soil, that is to say, if we consider it a dynamic organism and not a static model, we can understand how it is able to adapt to atmospheric conditions in real time. It opens its own structure to allow rainwater to drain without any runoff and holds on to rainwater in dry periods so as to keep its moisture at a stable and unaltered level to allow life. Consequently, this means that mulched and grassed clay soil will never present cracks or stagnation. It is true that clay soils depleted by previous destructive agricultural interventions (even if they were abandoned decades earlier) may appear compact. However, they will demonstrate an immediate tendency to quickly break down mulch through phagocytosis precisely to replenish the missing organic component and return to a crumbly and fertile state. In Elementary Farming, clay soil is the kind of soil mixture that is most likely to return to an excellent state in a short space of time.

Non-clay soils can also initiate assimilation processes and become fertile through Elementary Farming techniques, but they take longer. Once they have improved, these are referred to in school agronomy as “pseudo-clay soils”. In actual fact, they are soils that have become humus-rich clays, even though the geological origin of the mixture’s components is not that of pure clay. Even after reaching a certain level of fertility, following “conventional” processes, sandy soil may become desert again, tuffaceous soil may return to being compact, peat soil may go back to being asphyxiated and clay soil may become hard or muddy once more. The low electric cohesion of the particles that make up the soil is extremely unstable. To ruin thousands of years of nature’s work, it just takes a few seasons of farming processes, even if they are deceptively referred to as “soft” processes.

Invasive and toxic agricultural practices can kill off life in any soil. However, thanks to its ability to rebuild its own mineral and organic colloidal matrix, the land – any land – will also be able to recreate clay’s natural fertile conditions.


Clay soil

Example of soil before and after Elementary Horticulture, three months apart (Nicosia, province of Enna in Sicily, 2014)


24th March 2020

Gian Carlo Cappello


Gian Carlo Cappello