Showing posts with label phosphate. Show all posts
Showing posts with label phosphate. Show all posts

Thursday, August 18, 2022

Wild Free and Happy Sample 44 Update Nutrients

 [Note: The following is a significant expansion of the soil nutrients discussion of Sample 44.]

 

SOIL NUTRIENTS

All life depends, directly or indirectly, on essentials like sunlight, water, oxygen, carbon dioxide, nitrogen, phosphorus, potassium, soil, and so on.  In healthy wild ecosystems, these essentials are not depleted.  The magic of evolution nurtures their ability to adapt to changing conditions in the circle dance of life.

Agriculture operates in a far less elegant manner.  It’s a powerful, rowdy, perfectly unnatural, manmade monstrosity.  Its unpredictable mood swings can range from feast to famine, prosperity to oblivion.  In Mary Shelley’s classic horror story, the foolishly clever Dr. Frankenstein got cold shivers when his ghoulish monster turned to him and spoke these words, “You are my creator, but I am your master.”

Wild vegetation excels at recycling essential nutrients.  On the other hand, field crops excel at extracting and exporting nutrients, a slippery clumsy dance of destruction.  For example, phosphorus is transferred from the soil to the corn, from the corn to the hog, from the hog to the human, and finally flushed down the toilet, bye-bye!  Little if any is returned to the field to replenish what was removed from the soil.

Poop is precious.  Remember that.  In 1588, Anzelm Gostomski, a Polish gentleman, once proclaimed an eternal truth: “Manure is worth more than a man with a doctorate.”  In the modern world, every shipment of food that moves from the local countryside to faraway consumers is carrying away essential soil nutrients on a one-way ride, never to return.

To keep a farm operation on life support for as long as possible, efforts must be made to replace the deported nutrients.  Over the centuries, farmers have kept soil fertility on life support by applying stuff like sewage, manure, ashes, lime, bone meal, seaweed, compost, peat moss, guano, synthetic fertilizer, and so on.  In China, human wastes have been used as fertilizers for 5,000 years.  Traditionally, manure has been a popular fertilizer.  Gathering and spreading manure was far more fun than depleting the soil and starving. 

Even modest sized cities could religiously indulge in rituals that recycled holy shit.  In 1909, Franklin Hiram King visited Kyoto, Japan.  While traveling down a road one lovely morning, he observed a long caravan of men pulling cartloads of precious night soil from town.  They were in the process of returning this sacred life giving treasure to the fields where their food was grown. 

Each cart carried six 10-gallon (38 l) covered containers of delightfully fragrant plant food.  King noted that he passed 52 of these carts.  Then, on the return trip, he passed another 61 carts.  Other caravans moved down other roads.  He estimated that 90 tons of sewage was hauled out of town on that morning.  I wonder if this was a daily routine.

With the growth of population and urbanization, returning more and more human poop to fields that were farther and farther away, became impractical.  Eventually, imported fertilizers were able to save the day (temporarily).  Guano, phosphates, and synthetic ammonia were powerful, but nonrenewable.  Unfortunately, they accelerated population growth, forcing the jumbo sized mob to zoom faster down a one-way road to a less than utopian future.

Writing in 2001, when the population was a mere six billion, Vaclav Smil estimated that 40 percent of the people alive in 2000 existed only because of the intensive use of synthetic ammonia fertilizer.  It had succeeded in shattering the population ceiling (temporarily).

In order to survive in good health, all living plant and animal organisms must acquire the mix of nutrients that are essential for them.  Different species prefer different mixes.  David Montgomery explained that there are three absolutely must-have macronutrients for all plant and animal life (including you), for which there are no substitutes — nitrogen (N), phosphorus (P), and potassium (K).  General purpose “NPK” fertilizers contain portions of all three.  Humans acquire these essential nutrients by eating plant and/or animal foods. 

Nitrogen (N)

Vaclav Smil noted that all living organisms require carbon, hydrogen, oxygen, and nitrogen.  In the world, there are huge quantities of all four, but nitrogen is the oddball.  The air we breathe is about 78 percent nitrogen, but it’s not in a form that most living things can actually use. 

In the air, it’s a gas that consists of tightly bonded pairs of nitrogen atoms (N2) that are too stable to readily intermingle with other atoms.  Before it can be utilized by living organisms, it must be transformed via a process called nitrogen fixation.  In the soil are nitrogen-fixing bacteria that can combine nitrogen and hydrogen to produce ammonia (NH3), a compound that can nourish natural processes.  Ammonia is 82 percent nitrogen.

These bacteria grow on the roots of leguminous plants, like beans, soybeans, peas, chickpeas, peanuts, lentils, carob, alfalfa, and clover.  So, when you eat beans, your body is able to absorb the usable nitrogen.  After a legume crop is harvested, the leftover plant material decomposes, releasing fixed nitrogen into the soil, fertilizer for future crops.  This “green manure” is plowed back into the field.

When livestock graze, they absorb usable nitrogen from their food, and then produce “brown manure” that generously boosts soil fertility.  You and I commonly get our nitrogen when we digest the amino acids in high protein foods, including beans, leafy greens, nuts, seeds, eggs, milk, and lean meat.  At the rear end of the process, we expel a potent brown fertilizer called poop.

Old fashioned low tech farming could produce modest harvests when assisted by good luck and determined efforts.  Unlike modern industrial agriculture, old fashioned farm soil only provided modest amounts of usable nitrogen.  Low nitrogen content results in low yields, while high content boosts them.  So, nitrogen is a limiting nutrient, something like the gas pedal in a car.  So is phosphorus.

Ordinary soil generally contains modest amounts of N, P, and K.  Applying additional potassium (K) to the soil does little or nothing to boost crop yields.  But synthetic fertilizers can boost the content of nitrogen and phosphorus beyond normal levels, and this actually promotes bigger harvests.  Of course, bigger harvests can feed larger mobs of hungry humans.  

In the short version of nitrogen history, there were two huge leaps in fertilizer technology — guano and synthetic ammonia. 

Guano is an organic fertilizer created by dense accumulations of bird shit or bat shit.  Seabirds often nest on islands, where they are less vulnerable to pesky predators.  For the same reason, bats prefer to shit in the comfort and privacy of caves. 

Each day, seabirds gobble up lots of yummy anchovies, return to their nesting ground, and happily unload magic excrement.  Century after century, more and more piles of crap grew higher and higher.  Mounds of guano could have nitrogen content ranging from 8 to 21 percent by mass!  Holy shit!

In arid regions, like the Pacific coast of South America, the nesting islands were deeply covered with nutrient rich guano.  Islands off the shore of Peru used to be guano heaven — some deposits were over 200 feet (61 m) deep.  In wetter regions, birds also colonize offshore islands, and shit all over them, but rainy weather and humidity leaches out vital nutrients. 

According to Wikipedia, “The rulers of the Inca Empire greatly valued guano, restricted access to it, and punished any disturbance of the birds with death.”  Guano was used for centuries by indigenous folks.

By the 1840s or so, in Europe and North America, a persistent brutally abusive relationship between farmers and their precious dirt was taking a serious toll on soil fertility.  Meanwhile the mobs of hungry white folks continued snowballing.  How in the <bleep> are we going to feed them?  Trouble ahead!

White folks first learned about magic guano in 1802, via the writings of Alexander von Humboldt, which were translated into several languages.  Eventually, some ambitious lads experienced a breathtaking revelation.  Holy shit!  We could become filthy rich guano tycoons! 

As we all know, money is a devilish hallucinogen that can turn kind and decent people into batshit crazy idiots.  Consequently, humankind began a dramatic transition from traditional food production that utilized local manure, into a fast lane powered by imported bird shit.  In some locations, the guano had an exceptionally high content of nitrogen, phosphate, and potassium.  It greatly excited the productivity of field crops.

And so, in the nineteenth century, guano was the world’s super fertilizer, and a source of great wealth.  A guano gold rush was born.  Nations vigorously competed to claim ownership of guano islands.  Disputes triggered the War of the Pacific (1879-1884).

Traditions got tossed on the compost pile.  Farmers no longer had to devote lots of time to nutrient recycling.  They didn’t need to plant cover crops of nitrogen fixing legumes, or do crop rotations.  They could simply buy what they needed, magic bird shit, harvest far greater yields, and get rich quick.

Industrial scale guano mining was extremely disruptive to the seabirds that squirted out the valuable shit.  On Peru’s guano islands, bird populations plummeted from the 53 million in the late 1800s to just 4.2 million in 2011.

Of course, guano was a finite resource created over the passage of countless millennia, and it was being extracted as fast as humanly possible.  Production peaked around 1870.  Insatiable greed heads then directed their attention to the saltpeter deposits in the deserts of Chile.  Saltpeter is sodium nitrate, a compound that contained usable nitrogen. 

J. R. McNeill noted that by 1900, German farmers were highly dependent on imported guano.  Without it, they could no longer feed the growing mob of hungry Germans.  Gosh!  Wouldn’t it be wonderful if we could produce fixed nitrogen on an industrial scale?  Could it be possible?  Yes!  Unfortunately, two Germans figured out how.

Synthetic Ammonia.  I’d now like to introduce you to Fritz Haber and Carl Bosch.  In 1909, chemist Fritz Haber invented a process that could extract nitrogen from the air (N2), mix it with natural gas (CH4), and embed it in ammonia (NH3), via an energy-guzzling process of high heat and pressure.  Synthetic ammonia created a sharp turn in human history.  (Years later, Haber invented Zyklon B, the poison used in Nazi gas chambers.) 

Carl Bosch figured out how to perform this catalytic process on an industrial scale.  Haber and Bosch opened the first ammonia plant in Germany in 1911. 

Ammonia was also a feedstock for explosives, which were in high demand for countless bloody military adventures.  So, many new ammonia plants were built.  At the end of World War II, large quantities of ammonia became available for other uses, and the production of synthetic ammonia fertilizer soared.

In the second half of the twentieth century, the production of synthetic NPK fertilizers skyrocketed: 4 million tons in 1940, 40 million tons in 1965, and 150 million tons in 1990.  Far more food was produced, and the human population grew at an explosive rate.

Today, the intended benefits of these fertilizers are maxing out — applying more of it to a field no longer increases the size of the harvest.  But the potent fertilizer runoff is able to continue increasing the contamination of groundwater, rivers, coastal dead zones, and oceans.

Richard Manning noted that when farmers apply synthetic fertilizer on a field, less than half of it is absorbed by crop plants.  Fertilizer can acidify the soil.  Some of it dissolves and contaminates the groundwater that folks drink, and lots of it runs off into waterways.  Much of the U.S. Corn Belt drains into the Mississippi River, which is an ecological catastrophe. 

Fertilizer runoff stimulates the growth of algal blooms.  As the blooms die, they consume oxygen and emit CO2.  As the oxygen content of the water is depleted (anoxia), this can cause everything to die (eutrophication).  The Mississippi flows into the Gulf of Mexico, where it has created a dead zone the size of New Jersey.  The Baltic Sea is home to seven of the of the world's ten largest marine dead zones.  About half of U.S. lakes have low oxygen content, and the number of dead zones in the world continues growing (415 in 2022).

The National Science Foundation reported that fertilizer runoff is increasing the nitrogen content in rivers and streams, where microbes convert it into nitrous oxide (N2O), “a potent greenhouse gas, with a warming potential of approximately 300 times that of carbon dioxide.”  Nitrous oxide persists in the atmosphere a long time, and promotes global warming and acid rain (it’s also a pain reliever, laughing gas).  Cow shit is another source of nitrous oxide emissions, and their belches are a significant source of methane.

In the twentieth century, global population skyrocketed at a rate similar to the rapid increase in fertilizer use.  Nitrogen and phosphorus are limiting nutrients, and synthetic fertilizers exceled at sweeping away longstanding limits to crop productivity.  Julian Cribb wrote that the wellbeing of most of humankind is now heavily reliant on the use of these potent fertilizers to assure adequate food harvests.

Today, about 80 percent of synthetic ammonia is made using a natural gas feedstock — a finite nonrenewable fossil energy resource.  As natural gas prices rise, so will the cost of nitrogen fertilizer, which will increase the cost of food.  Political instability in the world is increasing.  A few nations have abundant reserves of gas, while all nations are dependent on reliable access to food.  This presents many opportunities for heavy handed dog-eat-dog mischief.

Phosphorus (P)

Like nitrogen, phosphorus is also a limiting nutrient.  It is always found in mixed compounds, never in pure form.  Much of the P in soil is in a form that plants cannot use.  This puts a firm ceiling on crop productivity.  In NPK fertilizers, usable P is provided by phosphate (P2O5), a mineral compound. 

When phosphate is applied to a field, crop yields are boosted.  When it runs off cropland into bodies of water, it can trigger eutrophication.  Phosphorus enters your body at the mouth, and departs via urine and excrement.  It’s possible to recover it from sewage and manure, but not cheap.  When mixed 50/50 with water, your urine is an excellent liquid fertilizer that contains both nitrogen and phosphorus — and it’s free.  Waste not!

Fred Pearce noted that every living cell needs P, and there is no substitute.  It’s as essential to plant life as water is.  We are great at misusing it, suck at recycling it, and it’s vital for feeding humans and other critters.  Each year, the world mines 170 million tons of phosphate.

The world’s primary source of phosphate rock is an open-cast mine in the Western Sahara, a region currently controlled by Morocco — an unpleasant situation that irritates the native Saharans.  Political instability in the region could disrupt the production and distribution of phosphate, and generate a food crisis in many nations. 

So, demand is rising, most of the world’s best phosphate reserves are gone, and those that remain are in just a handful of countries.  Most of these reserves are in hard rock form, which requires vastly more fossil energy to mine and process.  There are also large deposits of phosphates in deep sea locations, but mining them would be deeply expensive. 

When will phosphate production peak?  That’s a highly contentious question, because accurately estimating the remaining reserves requires lots of guesswork.  Today, of the three essential NPK nutrients, P is the most worrisome to experts. 

Just as I was about to send this info to the world, my faithful muse gave me a dope slap and directed me to an important research paper.  It’s written in super-cryptic science jargon, and ordinary readers (like me) may suffer some permanent brain damage, but it’s a fascinating horror story.

Christine Alewell and team put a spotlight on the latest news.  If global heating doesn’t blindside industrial civilization, phosphorus depletion will.  Big Mama Nature brilliantly guided the evolution of wild ecosystems that did a wonderful job of protecting precious topsoil and perpetually recycling essential nutrients.  Sadly, cleverness has pulled the rug out from under this delicate balancing act.  The tilling of agricultural soils eliminates the protective covering of wild vegetation, and exposes the delicate treasure below.

When P is not locked within solid rock, its water soluble.  When rain splatters directly on pulverized farm soil, gravity carries the P runoff elsewhere, like wetlands and streams.  Erosion causes about half of the P depletion in farm soil.  As P content decreases, so does the productivity of the field.  Harvests shrink.

Alewell noted, “The world’s soils are currently being depleted in P in spite of high chemical fertilizer input.”  In poor countries, where folks can’t afford potent fertilizer, the rate of P depletion is even higher.  In the long run, agriculture is not sustainable.  “Soil phosphorus (P) loss from agricultural systems will limit food and feed production in the future.”

To continue producing chemical fertilizer requires continued mining of nonrenewable geological deposits of P, an increasingly limited resource.  The P moves in a one-way flow from the mines, to the agricultural land, into freshwaters, and finally into oceans.

The “organic management” of P is also unsustainable.  A cornfield extracts P from the soil.  Then, the harvested grain is sent somewhere else, along with its P content.  Added manure and compost won’t replace all of the P exported.  Similarly, livestock grazing extracts the P from the greenery consumed.  Some of it is returned to the land via manure and urine, but some of it is sent away to the meat processor, never to return.

Potassium (K)

In plants, potassium is important for the synthesis of protein.  The potassium component of NPK fertilizer is provided by a variety of minerals rich in potash (K2O) that are found in the salt beds of ancient seas and lakes.  The K added to NPK fertilizer comes from nonrenewable mined sources.  David Montgomery noted that “potassium occurs in rocks almost everywhere in forms readily used as natural fertilizer.”  We don’t have to worry about near term potassium shortages.  Lots of other future crises are closer to the front of the line.

Toxic Sludge

Abby Rockefeller wrote a fascinating essay that thoroughly explored the long and exciting history of human pooping and peeing.  In modern cities, sewage treatment plants regularly generate sludge, which has to be removed and put somewhere.  Somewhere is often cropland. 

Besides the holy shit that happily splashes in your toilet, sludge also contains lots of weird stuff produced by industrial civilization.  For example, volatiles, organic solids, disease-causing pathogenic organisms, heavy metals, and toxic organic chemicals from industrial wastes, household chemicals, and pesticides.  Crops grown in fields treated with toxic sludge produce foods that may be less than wholesome.

BOTTOM LINE:  Bill McGuire reported that intensive industrial agriculture is depleting the quality of cropland soils.  In many parts of the world, including in the U.K., E.U., and the U.S., these soils are becoming “effectively sterile in the absence of regular fixes of artificial fertilizer.”  No free lunch.  No sustainable agriculture.  But eight billion get to pee and poop every day (for a while).  Hooray! 


Saturday, August 1, 2020

Wild Free and Happy Sample 44


[Note: This is the forty-fourth sample from the rough draft of my far from finished new book, Wild, Free, & Happy.  The Search field on the right side will find words in the full contents of all rants and reviews.  These samples are not freestanding pieces.  They will be easier to understand if you start with sample 01, and follow the sequence listed HERE — if you have some free time.  If you prefer audiobooks, Michael Dowd is in the process of reading and recording my book HERE.]

SACRED SOIL

Life Giving Sunbeams

All animals, including humans, run on sunbeam energy.  We can’t absorb it directly, via exposure to the sunlight, but plants can.  They use the sunbeam energy to create carbohydrates, the building blocks of life.  Animals that eat plants can then absorb those nutrients.  Animals that eat animals can acquire the sunbeams from their prey. 

If there were no plants, there could be no animals.  Grazing animals are able to survive because they can digest grasses and forbs.  Many other animals can’t, including carnivores and humans.  Humans are omnivores, meaning that we can digest nutrients produced by a wide variety of plants and animals.  To oversimplify, when more food is available, human communities can expand.  The availability of food is affected by variables including temperature, precipitation, soil fertility, and daylight hours.

In the good old days, the plants and animals in wild ecosystems coevolved over time, which helped them adapt to stable long-term survival in local conditions.  With the transition to plant and animal domestication, humans could produce greater quantities of food.  But the artificial ecosystems they created (cropland and pasture) had less natural diversity and stability.  By increasing food production, agriculture could free some people from manual labor, allowing them to pursue specialized knowledge and technological innovation.  More recently, with the transition to mechanized, high-tech, fossil powered, industrial agriculture, both harvests and impacts sharply increased, as did the population of humankind. 

Both food production and population have experienced catastrophic growth in the last century.  The next 50 years are going to be very different from the last 50 years.  A number of factors are now increasing the risks for food production as we know it, and for life as we know it.  We’re getting closer to peak global food production, peak population, and the end of economic growth.  On the following pages, I’m going to briefly discuss some of these food-related factors, while paying more attention to farming than herding.

Soil Creation

David Montgomery is fascinated by soil, and extremely disturbed by humankind’s intensifying war on it.  Dirt begins as mineral particles that become detached from solid rock.  This can happen because of temperature shifts, frost action, abrasion, water, bacteria, fungi, penetrating plant roots, and so on.  At first this dirt is lifeless, like sand.  If not disturbed, it builds up over the centuries.

At the ground surface, where sunbeam energy arrives, the dirt is exploding with life, especially in wetter and warmer climates.  This big magic layer is called topsoil.  A shovelful can contain more organisms than the population of humankind — worms, insects, burrowing animals, and microbes.  Under ideal conditions, it builds up over thousands of years, and provides a good home for green solar collectors called plants. 

Topsoil is nourished by biomass — dead vegetation, discarded leaves, rotting wood, carcasses, poop, and so on.  The composting team turns this organic matter into a treasure called humus.  Humus retains moisture, keeps the soil loose, improves soil fertility, and provides a home for the legions of wee organisms that are necessary for plant growth.

The roots of plants penetrate into the soil, where they retrieve water and nutrients.  Up above, the carpet of vegetation in the sunlight helps hold the soil in place, so it isn’t carried away by wind or water.  Topsoil is the foundation of the family of life.  It nourishes the beings that are alive, and composts the biomass they leave behind.  This complicated process of big magic has worked wonderfully for several billion years — without human managers, if you can imagine that.

Unfortunately, the powerful and relentless enemy of topsoil is human cleverness.  Some cultures became dissatisfied with simply adapting to conditions in their wild ecosystems.  They were irritated by the persistent itch of population pressure, an itch that can turn people into blithering idiots.  Spencer Wells lamented the transition to agriculture, when we began shifting from foraging to producing food.  “Instead of being along for the ride, we climbed into the driver’s seat.”  We had no idea of what we were doing, or where we were going.  Richard Manning agreed.  He said that in the good old days, “we didn't grow food; food grew.”

Soil Destruction

Walter Youngquist wrote that the average depth of topsoil, around the world, is less than one foot (30 cm).  He added that almost all modern folks consider oil to be a vital strategic resource, but few have a similar appreciation for soil.  We can live without oil, and some day we will, once again, return to good old-fashioned, slower and simpler, oil-free living.  But soil is far more important to humankind, and to the rest of the family of life — yesterday, today, and forever after.

He warned that, from a human timeframe, topsoil is a nonrenewable resource, because new topsoil is created over the passage of centuries, on a geological timeframe.  “Overall, one-third of the topsoil on U.S. cropland has been lost over the past 200 years.”  Humans are destroying it far faster than nature creates it.  Some say 10 times faster, others say 20 or 40.  He mentioned the work of Peter Salonius, a soil scientist who performed 44 years of research.  Salonius came to the conclusion that all extractive agriculture, from ancient times to the present, is unsustainable.

It’s common to see the wishful label “sustainable agriculture” used to describe methods and products claimed to have miraculous qualities.  The folks who use it depend on a blindfolded, gagged, handcuffed, and castrated definition of sustainability (or a lively imagination).  A genuinely sustainable way of life is one that can survive for many thousands of years without self-destructing, or diminishing the wild ecosystem.  Sustainable agriculture strategies imply a never-ending need for unimaginably dedicated, principled, and knowledgeable human management. 

Big Mama Nature’s wild ecosystems are brilliant living masterpieces.  They require no active management from tropical primates.  The healthy verb is “adapt,” like our wild ancestors did for most of the human saga.  The toxic verb is “control,” an approach with a time-proven record of smashing apart ecosystems, harder and faster with each passing year.  Human cleverness could never create a system so complex, which worked so well, over enormous spans of time.  Nature thrives in absolute freedom, and takes great pleasure in sabotaging the plans of ambitious control freaks, who seem fantastically incapable of learning from their repeated mistakes.

Wild is a holy word.  “Wilderness” means “disorder,” a place that is out of control — in other words, “free.”  The emergence of agriculture, herding, patriarchy, and civilization was a tragic shift into an unfree culture of intense control.  Wilderness is a place without paths or roads that lead to a destination, a place with no speed limits or law enforcement, a place where you are free to move as your spirit inspires you.  Robert Harrison asserted that bewilderment (be wilder) is about being fully alive.  He wrote, “When one is fully alive, the entire world is alive.”

The culture of control, on the other hand, is diabolically destructive.  Joel Bourne reported that every year, a million hectares (2.4 million acres) of world cropland are taken out of production because of erosion, desertification, or development.  Writing in 2000, J. R. McNeill wrote that the U.S. was currently losing 1.7 billion tons of topsoil per year to erosion.  In 2000, there were 281 million Americans.  So, the loss would have been six tons per person. 

Where is this heading?  Writing in 2012, John Crawford, a risk analysis expert, wrote that “A rough calculation of current rates of soil degradation suggests we have about 60 years of topsoil left.  Some 40% of soil used for agriculture around the world is classed as either degraded or seriously degraded — the latter means that 70% of the topsoil, the layer allowing plants to grow, is gone.”  [LOOK]

In some locations, visible evidence of this loss is obvious, in large clouds of dust, erosion gullies, or runoff that looks like chocolate milk.  In other places, the loss may not be readily visible during a lifetime.  When you gaze at a large field, decade after decade, you might not notice tons of gradual soil loss.  Youngquist mentioned a study finding that when one hectare of land lost six metric tons of soil, the surface of the soil dropped just one millimeter.  He thought that erosion was similar to cancer, a persistent intensifying destroyer.

Soils with less humus absorb less water, which increases runoff and soil loss.  Light soils like loess are more likely to disappear than dense heavy soils.  Sloped land is most prone to erosion.  Some regions of Europe typically receive gentle rains, while some locations in the U.S. often receive heavy cloudbursts that cause rapid runoff.  Of course, wild grasslands and forests excel at absorbing moisture, building humus, and retaining soil. 

When forest is cleared, or grassland is plowed, the soil is exposed to incoming sunlight.  As the soil warms up, microbial activity is stimulated, which accelerates the oxidation of the carbon-rich humus.  Precious carbon built up over the passage of years is dispersed into the atmosphere as carbon dioxide.  Soil fertility declines, and will not be promptly restored, if ever. 

All tilling, to varying degrees, degrades or destroys soil.  The healthy green blanket of natural vegetation that protects the precious topsoil is entirely stripped off the face of the land.  This leaves the defenseless, viciously pulverized, bare naked soil exposed to the merciless abuse of dangerous control freaks.  The soil dries out, hardens, and absorbs less precipitation, which accelerates runoff.  This increases the chances of sheet erosion, gullying, landslides, and flooding.  It can sometimes take centuries for nature to replace the unprotected topsoil lost in a stormy hour. 

Long ago, the Mediterranean basin became a hotbed of civilizations as agriculture spread westward out of Mesopotamia.  The Mediterranean climate provided heavy winter rains, making it a suitable place to grow wheat and barley.  Much of the basin was sloped land, which was extensively deforested over time, driven by growing demand for lumber and firewood. 

Flocks of sheep and goats roaming on the clear-cut hillsides overgrazed, encouraged erosion, and prevented forest recovery.  By and by, the rains leached out the nutrients, and washed much of the fertile soil off the hillsides.  In many locations, bare bedrock now basks in the warm sunshine, where ancient forests once thrived in ancient soils.

Vernon Gill Carter noted that, in the good old days, the Mediterranean used to be among the most prosperous and progressive regions in the world.  But when he wrote in 1955, most of the formerly successful civilizations had become backward.  Many had just a half or a third of their former populations.  Most of their citizens were reduced to a low standard of living, compared to affluent societies.

Montgomery noted that these ancient civilizations often enjoyed a few centuries of prosperity, as they nuked their ecosystems.  Sadly, the soils of the Mediterranean basin were largely destroyed by 2,000 years ago, and they remain wrecked today.  They are quite likely to remain wrecked for many, many thousands of years.  Much of the region that once fed millions is a desert today.

I never learned any of this in school.  Instead, this region was celebrated as the glorious birthplace of civilization, democracy, and science.  It had incredible architecture and dazzling artwork.  It was home to brilliant writers and philosophers (no mention of slaves).  Many of our public buildings today, with their ornate marble columns, pay homage to this era when we first got really good at living way too hard.

Of course, progress never sleeps.  J. R. McNeill wrote a fascinating (and sobering) book on the environmental history of the twentieth century, when cultures blind drunk on gushers of cheap oil spurred a population explosion that probably caused the most destruction to Earth since the Chicxulub asteroid wiped out the dinosaurs.  (Will the twenty-first century be even worse?)

For example, he noted that in the world, about 430 million hectares (seven times the size of Texas) has been irreversibly destroyed by accelerated erosion.  “Between 1945 and 1975, farmland area equivalent to Nebraska or the United Kingdom was paved over.”  By 1978, erosion had caused the abandonment of 31 percent of all arable land in China.  His book is 360 pages of relentless full dose reality that is guaranteed to bring bliss ninnies and hope fiends down from their fluffy clouds in dreamland.  It will inspire adults who are still capable to critical thinking to reexamine our culture’s myths of wondrous progress and technological brilliance.

Organic Fertilizer

Our lives are dependent on plant life.  Plant life is dependent on sunbeams, air, water, and soil nutrients.  In healthy wild ecosystems, these nutrients are continuously recycled, century after century.  Plants acquire nutrients from the soil, which are passed on to the deer, maybe passed on to the mountain lion, and finally returned to the soil again — a happy living merry go round that never stops. 

It’s a different story with agriculture.  The crops absorb the soil nutrients, their edible parts are harvested, and hauled away.  The nutrients in the exported food are never returned to the soil.  Harvest by harvest, soil fertility is depleted, and the nutrient content in the harvested food declines.  Attentive farmers in ancient Greece and Rome were pained to observe that with each passing year, crop growth was less robust, and the harvests were smaller.  This was not a path with a future.

For several thousand years, this hemorrhage of nutrients was slowed a bit by holding livestock in confined pastures, collecting their manure, and spreading it on the tilled fields.  Critical thinkers will instantly recognize that moving the nutrient-rich poop from the pasture to the field depletes the nutrients in the pasture’s soil — a downward spiral.  No free lunch.  Farmers in many regions tried many different ways of keeping soil fertility on life support, by applying sewage, manure, ashes, lime, bone meal, seaweed, compost, peat moss, and other stuff.  In China, human wastes have been used as fertilizers for 5,000 years.

There are three absolutely must-have nutrients for all plant and animal life (including us), for which there are no substitutes — nitrogen (N), phosphorus (P), and potassium (K).  Modern synthetic fertilizers include portions of each in their NPK products.  Humans acquire these three nutrients by eating animal foods and/or plants. 

Phosphorus and potassium are elements in mineral compounds that plant roots extract from the topsoil they grow in.  Nitrogen is 78 percent of the air we breathe, but it is not in a form that living things can use.  Atmospheric nitrogen consists of pairs of nitrogen atoms (N2).  Luckily, in the soil are nitrogen-fixing bacteria that convert atmospheric nitrogen into ammonia (NH3), which can be used by living things.  These bacteria grow on the roots of leguminous plants, which include peas, beans, clover, and vetch. 

While livestock acquire nitrogen from the grass they eat, they retain a third of it.  So, their manure did not replace all of the nitrogen extracted from the soil by the grass.  To maintain the nitrogen content in the soil, farmers had to invest time and labor to regularly plant cover crops of legumes.  Please take a moment to appreciate how wild ecosystems automatically and elegantly recycle nitrogen, while the process in control freak cultures requires an investment of time and labor.

For the corn-growing civilizations of Mesoamerica, livestock was not an option, so they carefully gathered the precious nutrients excreted by humans, and returned them to the cropland from whence they originated.  This must have been an endlessly fun-filled process in the city of Tenochtitlán (now Mexico City), home to 200,000 folks who had no wheeled carts or (nonhuman) beasts of burden. 

In 1909, Franklin Hiram King visited Kyoto, Japan.  One morning, he observed several processions of carts, each bearing six 10-gallon (38 l) receptacles of city wastes out to farms.  In the five hour period he watched, these caravans moved at least 90 tons of waste — and this was just on one road.  Other roads had similar traffic — day after day.  Humans did not evolve for city living.

The waters off the coast of Peru are home to lots of phytoplankton (wee plants), which are consumed by lots of anchovies, which are consumed by lots birds, who excrete a magnificent fertilizer called guano.  It is exceptionally rich in nitrogen, containing from 8 to 21 percent by mass.  Farmers used it during the Incan Empire to fertilize their fields.  Over the course of thousands of years, seabirds deposited guano on offshore desert islands.  Guano deposits in wetter climates are far less potent, because rain leaches out the precious nutrients.  Some Peruvian deposits were over 200 feet (61 m) high. 

By the 1840s, agricultural productivity in North America and Europe was wheezing, due to declining soil fertility.  Traditional farming methods were setting limits on the number of people who could be fed.  Guano was a potent nitrogen-rich medicine, and a guano gold rush commenced, which led to the War of the Pacific (1879-1884).  Farmers who used guano no longer had to regularly recharge their soil by planting cover crops of nitrogen-fixing legumes.  This enabled them to produce more food.  Guano production peaked around 1870, as attention was shifting to the saltpeter (sodium nitrate) deposits in the deserts of Chile.

Inorganic Fertilizer

While fertilizers like guano and saltpeter provided nitrogen, phosphorus was more challenging.  Applying ground up bones was not especially effective.  The need for a potent source of phosphate inspired the development of a synthetic fertilizer — superphosphate.  Beginning in 1848, crushed phosphate-bearing minerals were treated with sulfuric acid, and a star was born.  Of the three most essential nutrients (NPK), phosphorus is the most worrisome.  Some say that the production of phosphate minerals peaked in 1989.  It can be recycled from sources like compost, urine, bones, and sewage, but not on an industrial scale.  Eventually, shortages can be expected to retard the human juggernaut.

The potassium component of NPK is provided by a variety of minerals rich in potash (K2O) that are found in the salt beds of ancient seas and lakes.  These minerals are fairly abundant, so far, but not forever.

J. R. McNeill noted that by 1900, German farmers were highly dependent on imported guano.  Without it, they would not be able to successfully feed Germany.  In 1909, chemist Fritz Haber discovered a process that could extract nitrogen from the air (N2), mix it with methane (CH4), and embed it in ammonia (NH3), via an energy-guzzling process of high heat and pressure.  Then, Karl Bosch figured out how to perform this process on an industrial scale. 

In 1911, Germans began the commercial production of synthetic ammonia, which contained nitrogen in the plant-friendly form, bypassing the ancient dependence on soil bacteria, and reducing agriculture’s addiction to livestock manure.  The Haber-Bosch process also provided nitrates used to make high explosives, as the world was moving toward the First World War.  Today, about 80 percent of synthetic ammonia is made using a natural gas feedstock — a finite nonrenewable resource.

Writing in 2001, when the population was a mere six billion humans, nitrogen expert Vaclav Smil estimated that 40 percent of the people alive in 2000 existed only because of the intensive use of synthetic ammonia fertilizer.  It had (temporarily) pushed back the limits on population size.  The population explosion was also accelerated by the Green Revolution, discussed later.

In the second half of the twentieth century, the production of various synthetic NPK fertilizers skyrocketed: 4 million tons in 1940, 40 million tons in 1965, and 150 million tons in 1990.  Far more food was produced, and the human population soared.  Today, the benefits of these fertilizers are maxing out — applying more of it to a field no longer increases the size of the harvest.

Richard Manning noted that when farmers apply synthetic fertilizer on a field, less than half of it reaches its intended target, the crop plants.  Some of it dissolves and moves into groundwater, and lots of it runs off into waterways.  Much of the U.S. Corn Belt drains into the Mississippi River, which is an ecological catastrophe.  Nitrogen stimulates algae blooms that deplete the oxygen content of the water (anoxia), which can cause everything to die (eutrophication).  The river flows into the Gulf of Mexico, where it has created a dead zone the size of New Jersey.  About half of U.S. lakes have low oxygen content, and the number of dead zones in the world continues growing (over 400 in 2008).

And so, dear reader, this is a brief peek at how agriculture has impacted the planet, from the perspective of soils.  The full story is much longer, more complex, and far worse.  Human cleverness is like a wildfire in a bone dry forest on a very windy day — nothing can stop it, it just keeps destroying.  This provides a profound lesson on the incredible elegance of the healthy wild ecosystems that Big Mama Nature nurtured for eons, prior to domestication.  Natural time-proven wild sustainability is essentially perfect, a masterpiece.  Honor it with respect and reverence.