Here’s some soil:
It’s a series of shelters, which capture water, minerals and heat, and amplify the conditions for light and seed germination, in the warm area in the first millimetres above the earth’s surface.Yes, I know, this isn’t “soil” as the dictionary defines it:
The top layer of the earth’s surface in which plants can grow, consisting of rock and mineral particles mixed with decayed organic matter and having the capability of retaining water.
But look at this:
That image of moss fulfills this definition of soil (the 5th of five in online dictionaries):
A place or condition favourable to growth; a breeding ground.
Such a breeding ground can become complex:
That’s definitely soil, and is full of life. It’s also a growing surface. The common definition looks like the corn (and tomato) field below:
Note the chopped up cornstalks, and the chopped up and shredded plastic sheeting, designed to heat this ground up to achieve a similar effect to the one the mound of moss in the image below does on its own.
Mounds have been shown to dramatically raise the temperature of their environments and are the chosen form of plants in extreme environments. Notice how the mound above has a fellow traveller, a sprouted flowering plant putting out its first leaves. The flat, warm surface of the earth has been amplified, and in this heat, with the water that is trapped in the moss, like this water caught between these pine needles, …
… the plant has many basic needs fulfilled. Rather than flowing away, the water is held by the tension between two surfaces, at which point its own surface tension, amplified by the support of the surfaces around it, is stronger than gravity.
The “agricultural soil” that is “the top surface of the earth” is doing no more: the soil has one surface, but beneath that surface all the grains of mineral of which it is formed amplify that surface area many millions of times, and allow that water to bind and defy gravity. It makes a web not that dissimilar from the multi-year complex of this stag horn sumac:
Plants pick it up from there. Above ground, none of that is visible. It looks like “soil” is a magical mineral and compost mix, not that that is a clumsy approximation of a complex life-giving environment.
This subterranean story is not much different from the moss story except that the agricultural version of this soil is a simplified, manufactured material. Plant growth is chopped up and tilled into a mineral substrate, along with its plastic heating technology; simple bacterial and fungal growth, feeding off of the petroleum-based fertilizer which has provided nitrogen, essential for plant growth (and otherwise obtainable from the atmosphere, at least in complex living environments) decays that material into water-absorbing cellulose filaments and releases trace minerals, which another generation of plants can use. It’s an intervention.
It’s not pretty, though, and it’s a very simplified system that, without the application of nitrogen fertilizers or industrially-grown and sown seeds, produces only simplified weed cultures, of little value to anyone.
It is a new age of the earth. No-one knows what these weed ecologies are doing, because no-one is watching them. Certainly, they are building soil, and that is most true, but what, then is soil? The manufactured, mulch product, such as this desert landscape with unpicked tomatoes?
No, it’s far more. It is recreating life. Here’s a clue, from the shade under an old sagebrush plant on the hill.
Soil is a complex environment of fungi and bacteria and other microorganisms. They are the living things that cluster around the roots of plants like these blue bunch wheat grasses…
… or around the roots of larger plants like this robin-rich cottonwood …
… and recreate the living soil surface in the complex weather patterns of the underground atmosphere. Yes, there is one. When the air content of soil goes below a certain threshold, through either compaction or water saturation, everything dies. Air is key. After all, these plants couldn’t tolerate drowning.
Neither can their sisters underground. The atmosphere above the soil is turbulent. In it, water is released from saturation into precipitation and is taken back up again to balance the pressure of the air.
It’s the same underground, except there the process is expressed through the work of up to 1,000 different species per cubic metre of grassland soil; there, water, clinging to the mineral particles of the soil, attracts minerals, extracted not from the clouds by the sun and the cold, but extracted by microorganisms, and passed onto plant roots, which provide them with oxygen, which they breathe out. The large cousins of these microorganisms on the surface are doing this work, too. There we call it photosynthesis.
Each leaf is the earth. The earth is a leaf. Soil is not mineral. It is a living process of breath, as is the way leaves breathe the sun and the air and make stone move and bloom.
Next: more on the relationship between photosynthesis, soil atmosphere, plants and the sky.