Organic matter is the lifeblood ofsoil , the currency in the original hugger-mugger economic system . A soil ’s hunger for organic matter partly explains the mystery of why it disappears so quickly , but it does n’t explain how . Standing around above dry land imagine you ’ll solve this closed book is futile . The activeness is belowground . There , beneath your human foot , microbes and turgid life course create complex and dynamic communities where everyone has a dual persona — eat and be eaten .
The “Soil Dogs”
The leaves ( and wood chips and coffee priming ) first attract soil organisms with dentition or teeth - like equipment — the chompers , shredders , slicers and tearers . These organisms do the work that a clique of dogs would do if given destitute rein in a room filled with ivory , skid and fuzzy clod .
Insects and Worms
Most gardeners are familiar with some of the frank of soil living — earwigs , beetles and angleworm . They complain off the process of peel utile nutrient out of constitutional matter until simple compounds of carbon , atomic number 7 and hydrogen are about all that rest . fishworm do impressive things despite their lack of teeth . Like birds , worms have a gastric mill between their mouth and breadbasket that contains tiny rock and roll fragments that grind leaf mush and other organic matter into smaller and smaller subatomic particle . earthworm go down on in 10 to 30 percent of their physical structure weight day by day , mixing and blend organic affair and unfreeze the product into the ground . Just like in a moo-cow ’s stomach , bacterium do a magical bit of work inside an angleworm , die down constitutive matter and rock minerals into nutrients for their host to absorb . What the insect do n’t practice passes into the soil .
Mites and Springtails
Smaller mites and springtail ( visible with a 10 - power handwriting lens system ) get in on the action . They are the ones that clip away all but the veins of a dead leaf , result their lace - like handicraft behind . All this bodily process results in a lot of finely ground constitutional topic and moist , nutrient - plentiful fecal pellets that make a red-blooded meal for fungi and bacteria .
Microbes do n’t have teeth and jaws or a ventriculus filled with bantam rock like wiggler . They do n’t demand mouth . They employ acids and enzymes to gnaw on organic matter . These microscopic workhorses are fussy than bee doing work in the soil similar to what happens in the first stomach of a cow . They not only break down constituent matter ; they also bet the role of supplier and distributor of the nutrients , tincture component and organic acids that plants take . So , while plants do n’t forthwith absorb organic matter , they do absorb the metabolic products of soil organism that feed on and break down organic matter .
Sir Albert Howard did n’t quite get the picture the details of this transformational feat , and Justus von Liebig was satisfied with the feeling that organic topic did n’t matter . But we now know that plants have always trust on a steady supply of organic matter to feed in the minor creatures on Earth — soil organisms who do the heavy lifting that keeps plants fed and land fat .
Fungi and Bacteria
Fungi and bacteria anchor the menagerie of soil life and are the main brokers in this underground world . Fungi take the booster cable in turn numb things back into live things , and sealed type specialize in eating dead wood , a particularly important function in nature ’s bustle about economy . The chemic armoury of fungi slowly breaks asunder the long chains of implausibly durable carbon - and - hydrogen - rich particle that form wood . Little else has the right stuff to dissolve the woody part of industrial plant . And whether digesting a log or a twig , fungi excrete metabolic products that feed other ground organism that , in turn , become a repast for more soil organisms .
Although Farmer have long despisedfungi as vectors of plant disease , they are really essential to imbed wellness and survival — and always have been . It ’s just that pathogenic fungus , like the microbes that get infectious disease in man , steal the show . Only latterly have we begun to appreciate the helpful varieties . Yet some symbioses between plants and fungi are so powerful that the one can not subsist without the other . The famous truffles rooted out by develop pigs in France only grow with sealed trees and thus can not be farmed . Many more connections like these put out up from the ground and ripple through the biosphere .
The fruitfulness and persistency of fungi is surprising given their touchy root structure . Hyphae , the below - ground , root - like component of mushrooms are so slight that it takes thousands packed together to gain the diam of a piece of ribbon . More than once , Anne left a megabucks of wood chips sit around for a few months longer than planned , and when she finally plunged her pitchfork into the pile , she would always discover golf - ball - sized clump of what look like cobwebs . Only the glob were n’t cobwebs , they were strands of fungous hypha .
Scientists may weigh fungi microbes , but hyphae are unlimited in how long they can produce . Forest meshing of fungous hyphae are the largest lifeforms on Earth , forming subterraneous networks that lead for miles . A individual teaspoon of productive ground can contain a half - international mile of fungous hyphae . Fungi secrete their wood - busting organic pane from the growing tips of hyphae , the manner weewee drip from the honker of a hose . This battery-acid bath helps further reduce already tiny leaf and woodwind particle , permit bacterium to get in on the action . And like fungi , bacteria further disintegrate organic matter with their own fret of chemical . In the above - ground world it would take a set of grind frankfurter jaw or spinning blades of steel to do the work kingdom Fungi and bacteria do in the soil . This dynamic duet is nature ’s janitorial and recycling avail . Without them we ’d soon be neck - trench in all in flora and animate being .
In the flora world even rocks process as intellectual nourishment so long as the right fungi and bacteria are in the ground . plow over a Lucy Stone on a forest floor and you may rule the bottom covered with prospecting hyphae sucking nutrients from bare rock . Some are particularly good at seeking out relatively scarce elements that works need a lot of — like phosphorus .
The Middlemen
Nestor T./Flickr
A humans of petite middlemen lives between the microscopic realm of bacteria and fungi and the humanity of seeable soil organisms . Like all middlemen , these organisms function as a pass - through , preying on each other and the chief decomposers — fungi and bacteria .
Protists
Protists , like paisley - shape paramecia , are one example of these middlemen . They propel themselves through the grime hunting for bacteria and piece on hyphae using rotating tussock of fuzz - like cilia . Amoebas too are protists . They direct the fluid have got within their cell walls to make impermanent social structure call pseudopodia ( false feet ) as they blot their path through films of water on and between soil particles in search of food or on the outpouring from predators .
Nematodes
nematode worm , a divers mathematical group of microscopic grovelling creatures smaller than a grain of Amandine Aurore Lucie Dupin , prey on protists , as well as bacteria . These multilevel predator - quarry interaction among microbes turn out to produce a key seed of botanically available nitrogen — one of the great three plant nutrients . Bacterial cells are deep in nitrogen , which means that the dope of predatory protist and nematode worm that dine on them is also nitrogen rich . This micromanure can contribute a substantial part of plant - available N to the soil — so long as bacterium are useable as a food beginning .
When microorganisms moulder stagnant industrial plant and brute , they put life ’s elemental construction blocks back into circulation , including the big three — atomic number 7 , potassium , and morning star — and all the other major nutrients and assorted micronutrient of import for works health . Moreover , microbes render nutrient right back to where they are needed — a plant ’s roots .
What’s Really In Organic Matter
Until recently , scientist retrieve that allorganic matterin grunge arrive from stagnant plant cloth . Walk around a temperate or tropical timberland and this view make horse sense . There are , literally , short ton of plant life part rest around — seeds , fruit , bark , leaves , twig and offset . But research worker found that bacteria contributed a surprising amount of dirt constitutional thing when they tag some with a unchanging atomic number 6 isotope and permit them slack in an experimental patch for almost a yr . Subsequent soil taste discover score of dead bacterium piled up on each atom of clay , sand and silt . In fact , idle microbes accounted for up to 80 pct of the soil organic matter .
Now that you recognise this , you may never look at a atomic pile of decomposition leaves quite the same again . Instead you might see a banquet table overflowing with intellectual nourishment for soil - populate dinner party guests who have the alone magnate to transmute their repast back into nutrients that plants can use all over again . As every live thing in the soil eventually becomes something else ’s meal , an endless cycle of eating , dying and pooping builds fertile soil from which fresh life saltation .
dirt life digests and suspire only about half of the carbon in constitutive matter , leaving the rest as dark - colored , decay - resistant carbon paper compounds known as hommos . The hardest - to - break down bits of constitutional matter , like the fragments of durable waxes and resins from leave-taking and woods , accumulate in soil as hommos . In our growing garden , it only contract a duet of age before we get down to see a layer of humus form , sandwiched between the mineral soil and the decaying organic affair on top . Fungi keep wreak away at hoummos to wring the last nutrients from rotting leave-taking . Humus itself is so process and transformed compared to the original type of organic matter that scientists still are n’t sure of its precise chemical substance war paint . But they do correspond that humous is a assay-mark of rich , fertile grease .
The botanical world fed itself long before we came along . Plants drop their cast - off component part on top of the soil or , in the case of numb roots , within the soil . Hungry dirt life eat this constituent bountifulness and in the appendage changes death into the elements and compounds that plants require , but ca n’t get from photosynthesis . It is symbiosis on a terrific graduated table . The hidden half of nature put to work the cutis of the Earth , weaving a carpet of biography that begins in the soil and ripple upwards to the plant life and animals that in turn bread and butter germ . They are the underground yin to the above - earth yang .
Excerpted fromThe secret Half of Nature : The Microbial Roots of Life and Health(W.W. Norton & Company , 2015 ) by David R. Montgomery and Anne Biklé . reissue with permission of the publisher . All right reserved .
