My Pile: Inner Workings (Part II)

The first Sunday of the new year. I let the dog out and follow him into the backyard. Each step makes a crunchy imprint across the frozen grass.

I take stock of my pile with a morning pee of my own over the wire mesh that girdles the backside. A tendril of steam rises through the damp stalks of seagrass cross-hatched across the top. A tea kettle on slow boil, my pile.

On the outside, my pile begins the new year complete, composed. A heap in full. It almost seems a shame to meddle with it.

But mess with it I will, for I have a holiday’s worth of gleanings from my kitchen and from the neighbors to contribute. I have more fresh supplies in store for my pile, from the yard and beyond. A bucket of seaweed, churned to mulch by the gathering high tides of winter, awaits, as does a white plastic bag of coffee grounds procured from behind the counter of the local java shop.

Plus, it’s a mild winter day with a mix of rain and sleet on the way. I could use some exercise and an outdoor diversion, a break between the football games on TV. My pile is my own private hot-stove league.

I do indoor chores while the sun slowly warms. I scoop the cold ash and charcoal bits from the fireplace into a brown shopping bag and set it aside.

I’m also long overdue to clean the half-filled 20-gallon glass aquarium in the den that’s home to Bubbles, the pet red-eared slider turtle. Soon the turtle is paddling about in his tank of fresh clean water, and I have a bucket full of murky green turtle effluent to add to my pile. Better that end purpose than flushing the slop down the kitchen sink.  Laced with nitrogen, urea and who knows what other nutrients that make up a Chinatown turtle’s night soil will be like adding jet fuel to my pile.

I assemble the rest of my stocks and implements alongside the left log wall, then scrape the frazzled toupee of seagrass hay to the side with a heavy gravel rake. Next I plunge the wide-tined hay pitch fork into the spongy wet leaves. I drag forkfuls back toward me to create a trench, releasing a faint whiff of the beach at low tide.

Excavating a space in my pile for an insertion of fresh green material.

I dig deeper into the time warp that is my pile, down through the stratified layers of past heapings, releasing whaffs of steam along the way. Two feet down, the tines of my pitchfork jab into a mat of flattened leaves like a fork sticking a phone book.

I stick my hand into the hole. The wall of leaves is cool to the touch. It seems my pile is combustible only in spots. The cold of winter is winning out over the hot flush of organic fusion.

But to each his own, say the smart folks at the University of Illinois Extension, on their Science of Composting website. My pile’s inner workings are sorting themselves out in their own time and way:

There are different types of aerobic bacteria that work in composting piles. Their populations will vary according to the pile temperature. Psychrophilic bacteria work in the lowest temperature range. They are most active at 55° F and will work in the pile if the initial pile temperature is less than 70º F. They give off a small amount of heat in comparison to other types of bacteria. The heat they produce is enough however, to help build the pile temperature to the point where another set of bacteria, mesophilic bacteria, start to take over.

Mesophilic bacteria rapidly decompose organic matter, producing acids, carbon dioxide and heat. Their working temperature range is generally between 70º to 100º F. When the pile temperature rises above 100º F, the mesophilic bacteria begin to die off or move to the outer part of the heap. They are replaced by heat-loving thermophilic bacteria.

Thermophilic bacteria thrive at temperatures ranging from 113º to 160º F. Thermophilic bacteria continue the decomposition process, raising the pile temperature 130º to 160º F, where it usually stabilizes. Unless a pile is constantly fed new materials and turned at strategic times, the high range temperatures typically last no more than three to five days. Thermophilic bacteria use up too much of the degradable materials to sustain their population for any length of time. As the thermophilic bacteria decline and the temperature of the pile gradually cools off, the mesophilic bacteria again become dominant. The mesophilic bacteria consume remaining organic material with the help of other organisms.

Into the maw of my pile goes the neighbors' bucket of kitchen scraps.

Into the maw of my pile goes the neighbors’ bucket of kitchen scraps.

Over the next two months, I’ll gouge out similar holes in a half a dozen places, hoping to spike my pile with enough hot spots to keep the biological processes churning through the cold months. Some hot, some cold.

What my pile does through the winter mystifies me, the obvious efforts of all these aerobic bacteria notwithstanding. Keith Reid, in “Improving Your Soil” supplies the most helpful explanation I’ve come across. As he writes:

“The usual textbook method of classifying the critters in the soil by species is not useful to most readers. It is more relevant to understand what these organisms do, so here, we have categorized the huge diversity of life in the soil by their functions.” Here’s the skinny from his book:

The Shredders
When fresh organic material is added to the soil, the shredders begin breaking it down into smaller pieces. As the shredders chew, they expose surface area that smallerorganisms can then access and also start to break down the tougher materials. The best-known shredders are earthworms. As they burrow through the soil, they eat organic materials that are broken down in their gut, mixed with mucus and excreted. The finely ground material left behind creates a rich buffet for smaller creatures.

The Decomposers
In addition to the shredders, fungi play a key role in breaking down big pieces of organic debris. Unlike shredders, however, fungi work from the inside out. Fungal hyphae can grow into decaying leaves, stems and even wood, excreting enzymes that destroy the bonds between cell walls, then digesting and converting lignin and cellulose into simple sugars the fungi can use.

The Digesters
Once the organic matter has been broken down into smaller pieces, bacteria and actinomycetes go to work. Through their sheer numbers, these organisms are able to access most of the easily digested materials in the soil and incorporate them into their bodies, with the sole purpose of making more bacteria. In the process, they release nitrogen, phosphorus, sulfur and other nutrients that have been bound up in the organic matter.

The Grazers
Bacterial and fungal growth attracts a whole population of tiny animals that feed on them in much the same way that cattle or sheep graze a pasture. These include protozoa, such as the amoeba and paramecium. Large numbers of mites and nematodes also fill this role. Not all of the nutrients consumed by the grazers are used for their own growth, and the waste they release hastens the cycling of nutrients into a form that plants can use.

The Hunters
Just as in aboveground ecosystems, there are specialized predators in the soil. This group includes many species of nematodes, mites and small insects. Aside from keeping the population of grazing animals in check, these predators continue the cycling of nutrients through the soil ecosystem.

The Fixers
One group of microbes plays a crucial role in the soil environment by taking nitrogen out of the air and “fixing” it in a form plants can use. Most nitrogen fixation is carried out by bacteria that live symbiotically with legumes, but a few species of bacteria and blue-green algae fix nitrogen without being associated with higher plants.”

Sums up Reid: “The reality is that an active soil life unlocks nutrients in the soil, making them more available to plants, but it does so only if those nutrients are present in the first place.”

Which is where I come into play.

I dump the bucket of kitchen slop into the bottom of the hole, twisting it into the bottom of the hole to fluff things up. In goes the neighbors’ bucket and bag of coffee grounds, like soup into a hollowed-out loaf of bread. Stir again. The fresh additions disappear into the matrix of brown leaves.

I spread dollops of seaweed across the excavated hole, then cover it with a loose collection of leaves gathered from my neighbor’s yard –my way of a thank-you for them hosting me for Christmas dinner. I drain the turtle stew into the mix; who knows what bacteria will sup up that nourishment.

I finish by drawing the blanket of rotting seagrass stems back across the top with the rake, and sprinkle with a dusting of wood ash and charcoal bits from the fireplace. Once again, my pile is whole, its inner workings cloaked.


My Pile: Topping Off

Here in southern Connecticut in early December, leaf season has peaked and passed. The yards around town have, mostly, been swept clean of fallen leaves, giving way to the bleaker, bare-bones look of early winter.

Each morning the yellowing blades of grass in my lawn are etched with hoar frost and crinkle underneath my footsteps as I venture out with the dog to walk the property.

My pile, a week ago crowned higher than my head with the last big crush of swept-up leaves and gathered seaweed, continues to settle in upon itself, exhaling nightly as it assumes a more graceful angle of repose. The crystalline morning dew sweeps up the front flank from the cold ground to melt away as wisps of steam vapor waft into the ether from the soggy, saggy top.

My pile is never done. It is, by definition, a work in progress, and I am never done with it. Today, as soon as the morning warms, I will top off my pile with the remaining leftovers from the holiday just past. My pile is more than a match for all that we create and consume.

I read in “Improving Your Soil – a Practical Guide to Soil Management for the Serious Home Gardener” by Keith Reid (Firefly Books, 2014) that “For every 100 pounds of fresh organic material added, a mere 1 to 2 pounds end up as humus.”

I’m fascinated by the disappearing act that is my pile, and Reid has the scientist chops to explain what’s going on underneath the surface:

Every time you mix pea vines or carrot tops into the soil, you unleash a cascade of biological activity. Insects, mites, snails and earthworms begin tearing the plant material into pieces as they eat their fill, creating residues that smaller organisms can access more easily. Fungal hyphae begin growing through the leaves and stems, excreting enzymes that digest the tough cell walls. Bacteria and other microorganisms colonize the exposed surfaces, absorbing the nutrients that have been released for the plants’ growth and activity. All these organisms convert carbohydrates into more organisms, while some is respired as carbon dioxide and returned to the air.

This growing population of fungi, bacteria and other organisms attracts the nematodes and protozoa that graze on this bounty to support their growth. They, in turn, are eaten by other organisms. As these creatures excrete waste products or die, they are cycled through more bacteria and fungi. At each cycle, some of the easily digested organic material is respired and lost, while the most resistant materials gradually accumulate. Eventually, only the toughest material remains – the black substance we know as humus—but it represents just a tiny proportion of what was originally added to the soil.”

To be fair, Reid is ambivalent about the value of composting versus adding raw organic material straight into the soil:

“I am a bit of a skeptic about compost and the suggestion that it is a magical solution to all our garden problems.

“There are lots of advantages to composting. The materials produced through the composting process are much easier to handle and mix with soil … nutrients are stabilized in forms that are slowly released in the soil.

“Composting is essentially accelerated rotting, [and] logic dictates that since it is the fungal hyphae and bacterial slimes produced during decomposition that help create a stable soil structure, there is a greater benefit to having decomposition occur in the soil. With composting, most of the biological activity happens outside the soil environment. But if the choice is between composting your old pea vines and returning them to the soil or leaving them on the curb for the garbage truck, I vote for composting!”

Composting has my vote, and although I “grasscycle” much of my grass clippings and mulch many a fallen leaf back into the ground as I mow, I grow weary of having to sweep and vacuum up all the flecks of such litter I track into my kitchen and onto my carpets. Besides, my life and garden would be much poorer without the ongoing backyard science experience that is my pile.

So I will keep stuffing the ballot box that is my pile with the raw organic material that it likes best and that I have on hand. I have two more buckets full of pungent seaweed gleaned from the nearby seashore; another plump plastic bag of shredded office paper, and a small bucket of scraps from my kitchen.

Topping off my pile Dec 2015.jpg

The bottomless (or topless) pit of my pile, ready to receive more leftovers from the kitchen, office and nearby sea.

I skirt the old wood stockade fence along the backside of my property to check on the bigger metal ash can my neighbors keep outside the back door to their kitchen and find the lady of the house stuffing it full with the last of the Thanksgiving leftovers. She has a spare plastic bag packed with the soggy sheaves of newspaper from their rabbit’s cage; she begins to apologize for her youngest daughter being so neglectful of late in cleaning the hutch, but I am happy to take the load off her hands.

I glance toward the back of their small, fence-in yard to notice a low ridgeline of leaves raked just far enough away from their picnic table to be out of the way. She’s diligent in keeping her front yard tidy, and through the fall has swept up her leaves into piles for me to drag over to my pile with a bed sheet, but has yet to tackle the backyard. She knows that on through the winter I will help finish the task, as my pile is like the bear in the storybook and always wants more.

My gleanings assembled, I take the wide-tined hay pitchfork and, turning it upside down, tease the top of my pile from the center to the edges, releasing billows of steam vapor from the dank mix of whole and chopped leaves. Into this newly formed caldera I scatter the bright white office paper, then chuck the upturned plastic bucket full of kitchen scraps from next door. I gingerly tease the rabbit-hutch mess from its plastic bag, and use the tip of the pitchfork to separate the soggy, urine-soaked newsprint. The value of the bunny’s contributions to my pile far outweigh my squeamishness in handling the mess, but just the same, I cover it up with a thin layer of leaves raked up from the front of my pile.

The buckets of seaweed are next, and I stick the pitchfork into the mix to dredge up a tangle of sand- and shell-flecked rotting lettuce from the sea and sprinkle it across the leaves. I always like to stop to examine the flotsam. There must have been a mass molt among the crabs, for this batch is suffused with their carapaces.

I finish by taking up the four corners of the bedsheet full of damp maple leaves and, stepping up along the top of one of the log walls that frame my pile, drag the sack up and unfurl the groaning load across the top.

My pile, newly suffused with a fresh load of raw organic material, has returned to mounded form, and underneath its new cloak of old leaves, will continue the unseen magic of its transformation into something much less, and much more.

topping off

What looks like a big ol’ pile of dead brown leaves actually conceals a riot of “accelerated rot.”