Soil: A Narrative
Written by: Cass C
Published: 2025-07-02
Nature, Science, and a Great Misunderstanding
As fate promises, there is a common future for all existing beings: to end up as a corpse, rotting into the dirt. A morbid concept, perhaps, but it's something that I have gained an appreciation for, as a soil scientist. Despite the terrestrial nature of soil science, the words of Carl Sagan tend to haunt the brain.
Our Sun is a second- or third-generation star. All of the rocky and metallic material we stand on, the iron in our blood, the calcium in our teeth, the carbon in our genes were produced billions of years ago in the interior of a red giant star. We are made of star-stuff.
- Carl Sagan
Of course, it is romantic to think that the elements making up your tangible flesh are the same ones making up the mystic cosmos which captivate the mind on sleepless nights, but before you can be a star, shining down on the infinite universe, you will be any number of other things here on earth. But the first thing that you'll be, after your short human existence, is certain: soil. To most, soil is far from awe-inspiring, it's the dirt you walk on, the mud on the tires of your car after a long rain. However, I hope to convince you of its wonder. As one of the most misunderstood aspects of our natural world, soil is a rich, living, natural resource with vital importance to life as we know it.
Chapter 1 – A Recipe
The creation of a soil, pedogenesis (this name confused me at first, too), starts with regolith—raw, rotted rock, unconsolidated raw minerals that are ready to be freed from their crystalline prisons. Upon exposure to water, which acts as an acid, salts from these minerals are dissolved and clay solids are left behind. A small amount of plant life can begin to establish itself, now having access to nutrients that were previously tied up in the regolith.
As plants live and die, organic material begins to find itself in the developing soil in form of dead plant material and animal remains/droppings, making for perfect microbe food. As organic material is eaten by soil microbes, it is broken down into nutrients essential for plant growth (most importantly, plant-available nitrogen), allowing for advancement of plant life. Decomposing soil organic matter (SOM) also serves another purpose to plant growth. Organic carbon, a key component of SOM, is not readily decomposed like other elements, and can instead become a dark brown, sludgy material—aptly named humus.
Humus molecules, which are some of the largest, most complex carbon chains ever examined, are negatively charged. This causes them to hold onto important critical positive-charged nutrients preventing them from washing away. Additionally, humus can hold water in large quantities, an obvious benefit to plant life. All of this is the basic "recipe" for soil, but much like every family has their own potato salad recipe, every soil has their own unique characteristics, depending on its parent material, climate, and topography. Anything that can be considered a soil will host some degree of plant life, but the variable factors, of course, determine how fertile a soil is.
Chapter 2 – A History
One of the reasons for the fundamental misunderstanding of soil is the timescale on which it develops. As the child of two geologists, I have long been subjected to the concept of geologic time being too impossibly long for our human mind to accurately comprehend, to the point where one-million years is a mere blink of an eye. As it turns out, when you are a soil, one-million years is actually quite a long time.
If you are a mineral, the time you spend as a soil is a short phase, in between the more permanent affiliations of being a rock and being a salt dissolved in the ocean. The timescale for a soil typically stretches several thousand to several hundred-thousand years, depending on the environment where it is created.
This, when observing from a human perspective, puts soil in some strange middle ground of being somewhat regenerable, under nurturing conditions, but not renewable in the sense of solar or geothermal energy (especially under the continuation of current crop production demands and changing climatic conditions). This is precisely why the delicacies of soil health must be remembered, and agricultural practices must critically be evaluated to realize the consequences of the modern agricultural practices.
Chapter 3 – Agricultural Evolution
To understand how agriculture and soil health became so removed from each other, it is necessary to recall some agricultural history. Since the dawn of agriculture, naturally fertile soil has been integral to the development of society. The practice of fertilization using manure started early on, which stimulated microbial activity causing nutrients to cycle more quickly and allowed for the cultivation of more land.
More recently, crises in soil fertility have begun to arise. As human society advanced and the population grew, so did the demand for accelerating agricultural production. When nutrient regeneration in the soil could no longer keep up with the rate of nutrient depletion from increased cropping, there was a scramble to lay hands on nitrogen-rich guano, the finest fertilizer on the market circa mid-1800s.
But As the nitrogen-mineralizing soil microbes fell short on production, South American seabirds could not shit rapidly enough to keep up with the global demand for plant-available nitrogen. Thus the guano-war broke out as the world anticipated major food shortages once the last bat cave was scraped dry. In typical American-Imperialist fashion, the Untied States even passed a law—declaring that any island containing guano found by US forces could be claimed as American land.
Anyway, this guano-rush did not last too long, as a very aptly timed discovery was about to be announced. Nitrogen scarcity was almost instantaneously reversed to nitrogen abundance, when early 20th century German chemists Haber and Bosch invented the Haber-Bosch process, that harnessed atmospheric nitrogen into a biologically available state (ammonia, or NH3).
Chemical fertilizer quickly became the agricultural standard and was regarded as a truly heroic invention, allowing ag production to hit previously unimaginable levels, moreover, allowing for an explosion of the human population. Indeed, farmers everywhere had a new player on the scene, one that helped to develop the trend of intensifying the treatment of farmland. With this new nitrogen fertilizer, it was no longer a priority to input organic matter into the soil—plants could grow without it.
In the midst of agricultural industrialization, the misunderstanding of soil as a resource was revealing itself in the Great Plains of North America. To me, the Dust Bowl was always one of the most mysterious events in American history, but now the underlying cause is clear: the economic environment which fostered disregard of soil health to a hyperbolic extent.
Formerly stabilized by the deep roots of native grasses, midwestern topsoil was put under the plow. When topsoil is plowed, it is exposed to air, becoming oxygen enriched. This kickstarts microbial aerobic respiration, and SOM decomposition is expedited. The organic carbon which would otherwise end up as humus is gladly eaten by the oxygen pumped microbes, consequently leaving soil lacking organic material.
With importance of SOM having been deemed obsolete due to new artificial fertilizer, Great Plains farmers would leave soil to be SOM depleted without a second thought. That is, until drought loomed on the horizon. Remember, if you will, the absorbent property of humus. Without this organic sponge, a the drought that hit ravaged the Great Plains in the 1930s caused soils of the region to become parched. The dried-up soil not only was not hospitable to plant life, it was also left vulnerable to the unrelenting winds of the region. As the gusts raged through, hundreds of millions of tons of topsoil took flight, resulting in the bleakness of dust clouds and poverty that is characteristic of this era.
The Dust Bowl should never have happened, it was the culmination of an era careless agriculture, forgetting that without healthy soil, agriculture is fragile and artificially propped up by industrial measures.
Big Business & Imposing Issues
The work we are going about is this, to dig up Georges-Hill and the waste ground thereabouts, and to sow corn, and to eat our bread together by the sweat of our brows.
William Everard
As a young scientist, a part of the "next generation" of scientific minds, I suppose I am in the part of my career where I feel the existential duty to lend my limited expertise to problem. In the history of science, there has been an everlasting problem, perhaps one that is not possible to solve in its entirety, but is nonetheless very important to address—bridging the gap between science and society. In part, this story serves as a starting point for such a task, if by off chance you find your interest inspired by the paradoxically mundane and complex world of landscape pedology.
In today's world we come to find, anything that is of value to the capitalist system is at its mercy—and therefore faces the same fate of overexploitation, exhaustion, and being forced to work well past point of collapse. Soil is included in this category; maybe in this way we can all relate to the dirt beneath our feet.
Chapter 4 – Ag Markets
If you're anything like me, maybe you find economics to be the most torturously bland and artificial of all fields of study, the Subway sandwich of academia (I realize the humor of saying this while being stupefied by interestingly colored clods of dirt, but I digress). However much that I regret to admit it, it is necessary to conduct a quick lesson on how agribusiness works (we will look at the US ag industry, for a grotesquely capitalist example), in order to understand the reasons behind the excessive (and ultimately unnecessary) degradation of our cropland soil.
Coming down to it, it is fairly simple. As a crop farmer in America, the options to stay afloat are highly limited. The route most commonly taken is that of the government subsidies program, in which the goal is clear: produce as much yield per acre, no matter the cost. The method: fertilizer. The more N fertilizer added, the more bushels can be squeezed out of a plot. The efficiency of added fertilizer rapidly decreases, that is, the percentage of N lost to leaching greatly increases as the fertilizer amount further exceeds what is "necessary", but supposedly, the higher yield of the crop nets positive when the subsidy check arrives, making the lost fertilizer worth the farmer's money.
As discussed previously, relying on fertilizer (in lieu of nurturing the properties of soil that make it naturally fertile) to grow crops results in the farming process becoming removed from the health of the soil. Not only does this market that breeds overproduction pose a major environmental threat, but it causes the prospect of living as an independent farmer to be incredibly bleak and demeaning. The market's current demand of quantity over quality creates an influential incentive to land-grab and create mega farms. Small farms struggle to pay dues off of the smaller quantities produced, putting them in a position that makes life simpler to sell to a neighbor with more land looking to expand their operation.
To understand where the norm of overproduction came from, there is another lesson in US history. The farm subsidies program did not always reward mass production, in fact at one point (which ties in with the Dust Bowl and Great Depression) it paid farmers to periodically leave land out of production in order to prevent crop prices from tanking due to overabundance. But as ag production progressively became easier, there was a gap of opportunity for innovation relating to new applications of ag products. Thus came a plethora of new products to utilize crops: high-fructose corn syrup, livestock feed, ethanol, the list continues. And the best part, these uses do not require high quality (ie. high nutritional value) produce, meaning crops could be selectively bred based solely on the criteria of surviving in close quarters. This brings us to present, where the only way to win in the subsidized agriculture industry is to exploit the land for everything it's got—think huge monoculture fields and a downpour of ammonia deployed by a rig the size of a house.
Chapter 5 – Modern Threats
The story of soil degradation does not start and end with the ag industry alone. The desertification of land is a global issue that is driven by a multitude of issues and will be felt by all walks of life eventually. Even modern industrial agriculture, with all of the tools and tricks it can use to whip corn stalks out of a franken-soil, will be at a loss when the soil is too compacted, too devoid of biodiversity, too hot due to the global temperature increase (which potentially increases soil temp extremes to a greater extent than air) to hold water. The loss of fertile land is happening in nearly every corner of the planet, and much like the larger environmental crisis, a day will come that it is impossible to ignore.
While the decreased capacity for crop production is the most obvious impact of the soil crisis, it is not the only important factor which suffers due to soil degradation. Soil in itself is an ecosystem that serves a multitude of functions for life on Earth. Storage of carbon (via organic input) is a major function served by the soil, one that has caused stirring thoughts in the science community. With optimists thinking "the soil will save us" by sequestering carbon and preventing it from being released into the atmosphere, effectively offsetting human CO2 emissions, the more realistic consensus is that at best, carbon sequestration will have a net positive effect on the atmospheric carbon issue but is not the miracle fix that the "carbon-stock" industry (yes, companies have formed to profit off of global warming) claims it to be, and at worst, increasing global temperatures will reduce soil's overall capacity to store carbon. Sequestering organic carbon to this extent would also require ag producers to shift focus to building up soil carbon rather than their usual production means.
As increased global temperatures heat the soil thus altering its ability to offer important ecosystem services, a positive feedback loop between warming soil and the warming atmosphere has been suggested by a recent study, or in other words, increasing soil temperature extremes cause energy from the soil to be released into the surrounding atmosphere, causing the ambient temperature to rise with the soil temp. This effect must be continued to be studied to fully understand the extent that this can contribute to climate change, but it is a consideration that should not be ignored in the climate discussion.
Another major function of soil that I have previously outlined is worth revisiting—we rely on the soil to sink and cycle other vital nutrients. Bear with me as I take another brief nitrogen tangent. The humus of a deep, rich soil—as explored previously—is a master of immobilizing and storing nutrient particles, including nitrogen. Now, consider the large proportion of nitrogen fertilizer that leaches out of soil in agricultural systems in nitrogen surplus. Knowing that these thinning, industrialized soils typically lack the nutrient-sinking organic layer of a deep wild soil, we begin to see the reason why nitrogen fertilizer is so mobile in these thin cultivated soils. The consequence of lost nitrogen, beyond the farmer's lost money, is where nitrogen ends up—the waterways. There is plentiful literature on the negative effects of surplus nitrates in water systems (I don't doubt that you have seen articles about problematic algal blooms in various bodies of water), but the point is, there are rampant toxicity issues for wildlife and human populations alike that will continue to emerge as fertilizer runoff continues to be a problem.
Good News & Bad News
For all things come from earth, and all things end by becoming earth.
Xenophanes
Chapter 6: Good News?
The phrase "sustainable agriculture" has a reputation amongst environmentalists for being a common greenwashing buzzword used by industrial ag to claim that their corn monoculture is actually okay because they have adopted one or two sustainable methods that will never be elaborated on. However, the field of sustainable/regenerative/holistic (these terms are used interchangeably) agriculture is more promising than the corporatization of such words may leave you to believe. There are many dreamers and believers in the research world of soil health that have dedicated their lives to proving that there is another, greener, fate for the future of food production. Not only is there extensive research and theorizing about such methods, but a number of brave and progressive souls in the farming industry have jumped headfirst into soil and ecosystem conservation focused ag, with promising—and profitable results.
How exactly does it work? Realistically, the methods of optimizing an agricultural operation for the benefit of the soil and ecosystem are as localized and varied as the ecosystems themselves. Maybe you can sense where I'm going here—this is because the whole idea of such a system is to view the operation as a harmonious part of the ecosystem. To some it may sound like tree-hugger idealism, but really it is a straightforward concept. By growing crops that are suited to naturally thrive in the surrounding environment, and generally working with natural cycles and processes, the result will be less conflict between cultivation and nature. To shift a practice from industrial to holistic is a large commitment but is undoubtedly one that pays off. Farmers that have successfully done so can tell firsthand of harnessing natural powers to create less work and resource consumption for the operation over time.
Chapter 7: Why it's Not That Easy
The current commandeering held by industrial agriculture is quite a large and daunting block in the road when it comes to imagining a world where ecosystems and human crops not only exist together but do so harmoniously. The demoralized state of independent farmers makes it difficult to inspire the younger generations to be in the agriculture industry in the first place, even less to invest the effort to start fresh with new methods. Not only this, but the years of indoctrination to the minimally rewarding subsidy program and the debt caused by the huge expense of industrial equipment makes the ties to the system stronger and harder to cut. As I have alluded to, the hefty upfront commitment involved to restore natural processes on degraded farmland is naturally a major issue when it comes to implementing change, as a skeptical farmer is not able to timidly dip their toes in the water of sustainability and expect to see promising results. It is relatively easy to convey the concept of regenerative ag, but much harder to push those on the fence to have the passion to altering their operation.
The occurrence of the stubborn old farmer stuck in his ways, with a seemingly inherent hatred for any environmentalist policies is the key point to bridge the gap in vision and information. Realistically, the same disdain for the agricultural system is coursing through the veins of the old farmer as the environmentalist. It is the same system that fails both parties, but to inspire change requires common ground to be reached. By shedding light on the bold individuals that are paving the way for the holistic lifestyle we can exemplify that the benefits of sustainable ag are real, that they are more than idealistic theories invented by dirt worshipping hippies. The voices of these ambassadors must be spread, they embody the common ground that can and must be shared. There are inspiring projects underway to create discourse about sustainability among farming communities that make it clear that just one operation leaping out of the dismal "comfort zone" will inspire change amongst their neighbors. Those of us who know that this is a fight worth fighting, can make a difference through education, through inspiring landowners to take the necessary leap.
Clearly, we are far away from the reality of local, independent farms being the market standard, and living in the continually urbanizing world further complicates the vision of the future. But the good news is that we are only in the beginning phase of a large overall change. The more voices that join the sustainability discourse, the stronger the movement becomes. There are endless opportunities to empower the masses towards a better future. This doesn't only include the farming community, but the population at large. Exposing the consequences of highly processed ag products not only from an environmental health issue but as a nutritional issue, a human health issue, is a critical piece of the puzzle that can ultimately inspire awareness for the need of high quality crops. The more people that see this reality, the closer the change will creep from the horizon.
The industry works only for itself, its disservice to the common man is more apparent every day. Don't be fooled by the rhetoric, the soil will not save us. But if we save the soil, the thanks will come around to each one of us.
Soil Textures by Mindape