The Earth Hearing

by Daniel Plonix

  “Is this as unhinged as it sounds?”

  “I believe so, Your Grace,” replied Hagar. “Instead of being in the grassland, cycling nutrients and providing vital services to the ecosystem, a big portion of the world’s livestock is crowded in giant enclosures, while feed is grown, harvested, processed, and delivered to them.

  “There are many millions of square miles of grassland on Earth that cry out to be rejuvenated and know once again the hooves and fertilizing manure of massive, ever-moving herds of large herbivores.

  “The vast majority of the world’s livestock by weight consists of cows and buffaloes, over one billion and a half heads in all. In one swoop, its portion that is grain-fed can turn from an environmental liability to an asset, and at the same time help shed a full third of the millions of square miles of cropland dedicated to the cultivation of livestock feed. The cows and buffaloes would henceforth do the work. They would move and feed themselves, revitalizing the land in the process. Hogs and poultry can join the cattle, the grass in their diet would be supplemented by the enormous amount of food leftovers and discards in the wake of human consumption.”

  Hagar swiveled her stool to face the Earth people. “This is but one aspect of the environmental freak show you have wrought,” she told them. “If nothing else, had you boys routed all the manure of livestock back to the cropland, it would have provided it with an abundance of nutrients.”

  “What happens to the manure?” inquired one of the commissioners.

  “They typically dispose of it not far from the concentrated feedlots, Your Grace. So you have a few areas overloaded with nutrients and a great many areas that starve.” She lightly smacked her forehead, irrit­ation mixed with amusement. “The manure needs to be returned, as compost or otherwise, to the fields that generated the livestock feed. By the same token, everyone should do their civic duty: pee, shit, and return the nutrients into the big happy circle of life.

  “Each year, over 250 million tons of compost can be produced from human manure mixed with larger amounts of crop residues, returning to the soil 1 million tons of phosphorous. Most of the action is with the urine, though.” Hagar could perform the calculations with the speed of a computer. She gestured at the group of people from Earth. “Shower the fields with your pee and return to the soil each year something like 26 million tons of nitrogen, over 3 million tons of phosphorus, and about 10 million tons of potassium that each year you indirectly draw out from the fields for your consumption.”

  “How do you fancy we pee on the fields, exactly?” demanded one of the Earth people.

  “Oh, please,” Hagar said. “Use urine­-diverting toilets and funnel the liquid to a central processing facility. Employ magnesium oxide or bittern to precipitate the pee into an odorless powder. Or better yet, lime the urine using calcium hydroxide. Either way, you end up with a slow­-releasing phosphorus fertilizer. The leftovers, nitrogen and potassium, can be drip­-irrigated.”

  The striking blonde woman suggested human excreta and urine may yield a combined total of four million tons of phosphorus annually. The Terraneans were unsure what to make of this number, but one of them seemed decidedly unimpressed. “You realize the amount we spread on the croplands each year is over ten times that,” he said.

  Hagar eyed him. “Given the limited phosphate reserves, that’s nothing to write home to your parents about. At any rate, dumping so much of it on the field is a bit like flooding your apartment to wash your feet.” She considered it. “You are forced to apply large quantities to comp­ensate for the fact the mineral binds to various elements in the soil. And without the underground life-forms that can extract it, it is largely unavailable to most plants.” Hagar gave them a scornful smile.

  “Take white lupin,” she went on. “Its roots leak out copious amounts of acids that aid it in extracting phosphorus both from organic and inorganic sources in the earth. With an extensive root system, it discharges enough bioavailable phosphorus into the immediate soil environment to also support the growth of a companion crop. Buckwheat, phacelia, and most legumes harvest phosphorous effectively, too. And later their decomposition releases the mineral, making much of it bioavailable to the broader plant community.

  “Yet, you usually either not plant these species in the first place or bale and haul away their residue, thus removing a potential source of bioavailable phosphorous.”

  “Do I understand correctly?” asked one of the commissioners. “The Earth people mine phosphate?”

  She swiveled back to face him. “Yes, Your Grace. Mine, process, and transport it to fields worldwide. Most countries are forced to import it, having no phosphate mines of their own. Which may leave them in an untenable situation in the future. But as far as I am concerned, this point is moot.” She returned her attention to the seated people of Earth. “You don’t need the synthetic phosphate fertilizers. Under sound agricultural practices, adequate levels of phosphorous are cycling through the system. I refer to the combined volume of the mineral that is in the soil and in the crop residues, whether left in the field or returned later via cattle manure and human waste.

  “Same imbecility with the synthetic nitrogen fertilizer—only more so.

  “They drill for natural gas and subsequently combine it with the nitr­ogen in the air. The resultant ammonia is utilized as a feedstock for various nitrogen-based fertilizers, which are applied to vast areas of cropland.” She briefly glanced at the Terraneans. “They dump on the land each year over one hundred million tons of industrially manufactured nitrogen.

  “Let me spell out some of the broader outcomes,” Hagar said coolly.

  “Much of the phosphorus and nitrogen excesses leach into streams and water tables. Bodies of water are choking on the nutrients and algae are feasting on it, often producing algal blooms. Algae die, and in turn, bacteria feast on it, multiplying exponentially and draw on much of the oxygen in the water. This is how Earth has come to have hundreds of oxygen­-starved coastal zones where fish cannot survive. Dead zones.

  “The story of synthetic nitrogen fertilizer has a few more chapters distinct to it. Some of it is outgassed, in part as the potent greenhouse gas nitrous oxide. Some leaches into the water as nitrate, contaminating groundwater—which when used for drinking may block the oxygen-carrying capacity of hemoglobin or cause cancer.” She frowned darkly. “I should add that all this high-volume nitrogen production is much ado about nothing. After all, plants are swimming, as it were, in an ocean of air largely comprised of nitrogen.”

  “Yeah, well. There is a catch to that one.” It was the same Earth person from before.

  “No,” said Hagar. “But there is a wrinkle. Granted, being in a tightly bound form, nitrogen in the air is not available to the plants. Certain bacteria, though, can and do sever the bond, combine the nitrogen with hydrogen, and make it bioavailable. You could simply seed the kind of plant species that host these bacteria in their roots. After the host plants decompose, the nitrogen they’d utilized is bioavailable to the wider plant community.”

  The deputy director of the Nature Survey Group nodded. “Indirectly, a field can get its nitrogen needs from plant species such as red clover undersown with the main crop or through the cultivation of hairy vetch as a winter crop. In arid areas, drought-resistant crops such as pigeon peas can be used to provide nitrogen in a bioavailable form.”

  Hagar said, “Nothing in their conventional agricultural practices is sensible, sustainable, or resource efficient.” She jumped off the stool and many pairs of eyes followed her movements as she paced about the floor. “In fact, it is nothing short of astounding how disassociated the Terraneans are from the fundamental ways the planetary ecosystems operate.”

  “Why do you till the land?” queried one of the commissioners.

  “I suppose for the same reason we’ve done it for centuries if not millennia, sir,” one man in the front row said. “It works crop residu
es and animal manure into the earth. It pushes weeds under, allowing the crop to grow without competition. It also aerates the soil, spurring decay which in turn releases nutrients that promote plant growth.”

  Hagar sauntered over to the large man and playfully pinched his cheek. Before he could decide how to take it, she plopped down on his lap.

  “If you put your ear against a freshly-tilled soil,” she told him, “you could almost hear a whoosh sound as a portion of the carbon dioxide in the topsoil goes bye-bye into the atmosphere.”

  She walked back and mounted her stool. “Plant residues are not the only thing tillage works in. It also works in oxygen, fueling microbial growth. In the days and weeks to follow, it is an open season on the exposed soil organic carbon by an elevated number of microbes. This is how you end up having soils with less than 2 percent organic matter. At least that’s one of the reasons.” Hagar shook her head and sighed. “Its rider’s name was Tillage. And Hell followed it.” She viewed the Earth people. “You do realize tillage also destroys the channels dug by earthworms—channels that facilitate root growth—and it tears up a keystone species: arbuscular mycorrhizal fungi.”

  Many of the people looked at her blankly. Hagar looked back at them.

  “Let’s take it from the top, so you fellas understand the joy your agriculture brings to the planet,” she eventually said. “I’ll highlight a few energy flows in this hyper-complex ecosystem.” She glanced apologetically at the commissioners, then turned to face the Terraneans. “For the sake of time, I am going to make it quick and dirty.

  “With the aid of sunlight, plants synthesize water from the soil and carbon dioxide from the air to generate carbohydrates. They use part of the carbs for their own sustenance. The rest they exude via their roots into the soil, feeding the microbes and the fungi. At the end, this cascades outward and feeds the entire subterranean realm: earthworms, insects, slugs, nematodes, algae, protozoa, you name it.

  “In turn, bacteria and beneficial fungi provide plants with nutrients they extract and mine from rock surfaces and soil around them—copper, phosphorous, zinc, and a lot more.

  “Different plants at different stages secrete into the soil different chemical compounds that attract different bacteria. This shapes to no small degree the makeup and characteristics of the microbial communities that coat and otherwise congregate around the roots of plants. Through complex exchanges and communication signals, the microbes that sheath the roots are a part of its immune system, keeping the plant at balance with the broader life community around it.

  “Then there are the fungi. One species merits honorable mention.

  “Utterly depended on the secretions of carbohydrate compounds from the plants, arbuscular mycorrhizal fungi inhabit plant roots and become in effect their extension. The plant and the fungus have a mutualistic relationship. Beyond the nutrients these fungi provide, there is the matter of water supply. These fungi augment water uptake of plants by an order of magnitude and more. Two reasons for it. First, their hyper-thin filaments extract water from the smallest of pore spaces. Second, the extensive network of filaments markedly expands the soil area tapped. As a result, plants actively associated with the fungi are more likely to stay hydrated during periods of water scarcity. In addition, this mutualistic relationship brings plants a measure of salt tolerance and protection from pathogens, including nematodes.”

  She could see those things got their attention. A way to get plants to thrive in soil with higher salt content or drier conditions was important stuff. Really important stuff.

  “A lot more is going on underground than fungus-plant symbiosis. In truth, the complexity of the energy flows of this terrain and the diversity of its organisms is beyond the human ability to picture.” She paused and took a sip of water. “What you have here is a vastly complex resource network. A true interdependent soil community. Its infrastructure is made of mycorrhizal fungi strands, which link up most of the plants and also functions as a highway system on which microbes travel.

  “Furthermore, these fungal filaments secrete a sticky, waxy substance that forms water-stable soil aggregates. This facilitates tiny cavities that can store water and do provide habitats for microorganisms. These voids found between aggregates also function as passageways that allow the nitrogen from the atmosphere to reach microbes. In turn, the microbes sever the molecular bond of the nitrogen and make it bioavailable.

  “Enter exhibit A: tillage,” Hagar said. “You drag your disk rippers and disk harrows and disk chisels across the land—slicing, dicing, and churning. It is akin to running a termite mound through a giant tumbler—tunnels, conduits, termites, and all.

  “Subsequently, the fungal network is in disrepair, the life-harboring tiny cavities are gone, the volume of nutrient exchanges nosedives. The soil structure caves in unto itself and eventually compacts, both due to the outright destruction and due to the ripping up of the fungal network that makes the internal soil structures possible. Silt and clay particles fill the cavities in between and porosity plummets. We are talking about a general system collapse.

  “With repeated tilling, the soil is now compacted, and the water delivered by the occasional rain infiltrates but a little; the rest may end up as surface runoff. So now you clowns need to bring into the drier environments outside water to grow crops. Put another way, ten or fifteen inches of rainfall each year no longer suffice.” She paused. “Tillage is one of the agricultural practices that makes it impossible to raise crops in a semi-arid environment by relying exclusively on rainfall.” Hagar let this sink in.

  “This is where irrigation comes in: a fix for the problem of their creation. And it’s a good thing aquifers hold infinite amounts of water.” She leaned in and added in a stage whisper, “Because I sure would have hated to be that farmer in the future whose well ran dry.” She leaned back and resumed talking in her normal voice. “When irrigation water utilizes rivers and lakes, salt is delivered onto the land. In more arid climates, the evaporation of irrigation water from the upper layers of soil can leave behind a layer of salt in the root zone. This restricts plant growth if not outright prohibits it. Many tens of thousands of square miles of land now have a high salt content owing to irrigation, notably in India, China, Iraq, Pakistan, and Iran.

  “A related problem is waterlogging, where an impervious layer of subsoil makes it impossible for the water to work its way downward. The subsequent water buildup reduces oxygen levels in the soil, slowing growth and lowering yields.

  “Their agricultural practices are gifts that keep on giving.” Hagar smiled without humor, directing her words to the commissioners. “For however many months of the year, some producers remove all plants from the field, these very life-forms that would have synthesized and injected carbohydrates into the ground. Put another way, for however many months of the year, the soil biology receives no fuel. And it’s worse yet.

  “What do you think happens when the ground is compacted, bare, and devoid of the fungal strands that hold soil aggregates together?” she asked rhetorically. “The rainwater not only runs off but also removes some of the top layer—along with any possible bioavailable nutrients.” She considered the matter. “And when it is not the rains, it is the high winds that carry away the topsoil.” She was staring coldly at the Earth people. “Worldwide, tens of billions of tons of soil are eroded each year.

  “With the organic matter washing off, fine particles may settle in and cap the soil, exacerbating the problem of water infiltration. Moreover, in drier, hotter environments, the little rainfall that does infiltrate a compacted exposed soil tends to evaporate shortly afterward. Soil erosion, compaction, low moisture retention—in short, desertification.”

  The chair signaled her to halt, and the members conversed in low voices, conferring. At long last, he looked up. “Please continue.”

  “Yes, Your Grace,” Hagar said.

  “Different plant speci
es release differing nutrients into the soil. This gives rise to a wide diversity of microbes. In turn, this gives rise to that much more robust soil community, with far more biomass in the aggregate. It gets better. Different plant species growing in the same field produce roots of varying depths and varied spread patterns. In tandem with the fungal network, this provides more moisture from the various zones in the soil. In a long dry season, this can spell the difference between a wilting mono-crop or a flourishing field. Alas, many of the Earth people usually cultivate only one crop species in a given season.

  “To top it off, a single type of crop, with a fairly uniform height and leaf shape, translates to markedly lower capacity to capture solar energy and convert it to the carbon compounds that feed the subterranean biome. This makes the field that much more impoverished.

  “As a mono-crop offers a limited assortment of nutrients and habitat, it also has far fewer insect species that make those fields their home. With no checks and balances provided by diversity, a few species become dominant to the point of being pests. This of course means there is another problem in need of a fix. Therefore, the Terraneans spray insecticides. It gets better. Their new generation of insecticides are RNAi-based, which aim to flip off a critical sequence of genes in a pest. As usual, their ambition is further afield than their comprehension, and their simplistic linear approach in dealing with complex systems results in binding off-target sites of unintended subjects.

  “Courtesy of these destructive practices, the farm operators notice the plants don’t look so hot or grow so well.”

  Titters and gentle laughter filled the chamber.

  “To make up for it, they turbocharge the soil with macronutrients in the form of synthetic fertilizers.