Monday, February 20, 2012

Soil : Ashes to ashes, dust to dust.

 "Remember that you are dust, and to dust you shall return". With these words, Episcopalians will receive ash crosses on their foreheads this Wednesday, to mark the beginning of Lent, forty days of penitence and fasting.
     It is a particularly favorite worship service for me, in that it recognizes centrally the transitory nature of physical life, yet does so without condemnation or demeaning of that same physical existence. I mention it here as an introduction to talking about that dust from which we all spring, and to which we all return, the soil itself. Soil remains a fundamental aspect of sustainable living, yet it is poorly understood, overlooked, and too often treated "like dirt", a simile whose existence tells you about our cultural values.

     Healthy soil isn't dirt. Dirt is an inorganic mishmash of mineral particles. Soil is dirt suffused with organic materials, living things, water, and nutrients. If soil is a lake in the woods, fish leaping from the water and cranes tip-toeing through the lilypads, then dirt is a swimming pool filled with sterile tapwater. We've barely scratched the surface of the ecosystems present in healthy soil, but we've determined a few key points:
(1) Dirt provides nothing more than anchoring for plants; it has to be fed and fertilized constantly for plant growth to occur, as it has negligible "nutritional value". The difference between soil and dirt is the difference between eating vitamin-fortified oatmeal, and eating boiled cardboard.
(2) Dirt is, in effect, immuno-suppressed. Lacking normal soil life, dirt presents no resistance or competition to colonizing pathogens. Therefore, growing in dirt requires constant use of pesticides, fungicides, and insecticides.
(3) Dirt cannot hold water or dissolved nutrients well. Soil holds water and dissolved ions (potassium, nitrates, calcium, etc) exceedingly well, both in the living organisms themselves, and in chemical "traps" like humic acids. Dirt generally holds either no water at all (sandier soils) or forms a nearly-impermeable barrier (clays with no organic matter), neither of which help.

So clearly, we all know to farm on soil, not dirt? Except that isn't what we do. Our current food system depends on artificially-fertilized and propped-up dirt. We actually degrade the soil year after year by planting the same few high-value crops, pillaging the complex nutrient web then trying to "replace" it with massive doses of simple, single-chemical fertilizers. Again, from a human perspective, it's like eating all of the fresh, just-picked apples and pears out of your bowl, then "replacing" them for the next meal with a bowl full of powdered sugar and tap water (since, hey, they are roughly similar chemically speaking, right?) 

Historical perspective on soil destruction comes chillingly. Remember the dust bowl of the 30s, with parts of the great plains turning to dead, dusty, crop-killing emptiness? Less than a century previous, the first farmers in the great plains planted in top soil that was six feet deep. Millenia of migrating bison, pooping and grazing and turning up the soil, then migrating away for years before returning, had build an unfathomable store of soil wealth, which we tore through and washed out to sea in three generations. The magnificent cedar forests of Lebanon are mentioned in the Hebrew bible, in the Epic of Gilgamesh, and in ancient accounts of Lebanon as a country of deep green forests, verdant pastures, and rich life. Currently, much of Lebanon is dry scrubland, which happens when you cut down all of the trees. The loss of trees means little holds the soil together. The loss of soil means little can grow back to replenish the soil. And so forth.
     What can we do? Lots, actually, remembering that there are regions on Earth where humans have farmed for four thousand years, by maintaining soil health. This is a hugely complex subject, but some key points stand out:

1) Buy sustainably grown food. Get to know your food producers, and don't be afraid to ask questions about how they do what they do. Be an educated consumer - it's your planet, too, and this is stuff you are putting in your body.

2) COMPOST. Start a pile, or contribute to a friend's pile. Every time you remove matter from an area - you harvest fruit, haul away grass clippings, etc - all the stored energy and nutrients leaves the local system. Either the local system just gets weaker and weaker (the dust bowl) or you have to replenish that lost material (compost being the good, soil-building way; massive fertilizer use being the short-term, semi-effective way.) Once you start composting, you'll also be amazed at how much less total trash your household produces.

3) Make choices that build the soil, rather than mining it. Perennial (growing year after year, as opposed to annuals, which grow for one year and die) crops, trees, berry brambles - these send deep, soil-cultivating roots, and sequester more carbon every passing year, and help solidify and strengthen the local microclimate. Look into perennial vegetables like asparagus, taro, Good King Henry, sorrel, artichoke, Jerusalem artichoke, and perennial varieties of kale. If some of these are unfamiliar, don't feel bad - our food system shifted to almost exclusively annual crops in the last century, due in part to the mechanization of farming.

4) Bare soil is dirt in the making. Plant cover crops to hold and build the soil. Make your lawn much lower maintenance by switching to a clover lawn, or a mix of grasses and clovers. This also creates soil-building life, as clover is a nitrogen fixer.

5) Hugelkultur. Aren't you tired of me talking about this yet? If not, start reading here.

6) Biochar. More on this later.

7) Learn that many "annuals" are only annuals because we force them to be. An article on perennial garlic, featuring a man who understands how to stack functions like a master.

An excellent TED talk which covers many of these points.

Tuesday, February 14, 2012

Stacked Functions : the Bones of Permaculture

The soul of permaculture, its animating force and source of ethos and direction, is its intentional ethics of "earth care, people care, fair share" and its fundamental focus on decentralized, local sustainability. Truly, these beliefs elevate the whole exercise beyond 'just another way to plant tomatoes.'

However, I would say that the bones of permaculture - the structures by which it transmits the moral impetus of noble ideas, and transforms good intentions into magical results - the bones come to us in certain basic principles of action. One of the most powerful principles is stacking functions.

The principle of stacking functions dictates that, in a given system, each element should perform multiple duties. Understand from the beginning that this is profoundly different than "multitasking", that mostly-mythic story we tell ourselves to justify the insanity of trying to do eight separate tasks at one time, effectively doing none of them well or with attention. Multitasking is trying to do multiple tasks. Stacked functions is succeeding in being multiple things.

An easy mapping out of the concept comes from visualizing every element of a system in terms of the same basic characteristics - what does it need? what does it produce? what does it do? - and connecting those needs, products, and actions into other outputs, needs, and places in the system.

When I planted a dwarf pear tree in my front yard, I stacked many useful functions. First, the dwarf pear produces edible fruit, meeting my need for good food. Second, during the heat of the summer, its leafiness will give partial shade to the area around it, protecting it from overpunishment of late summer sun. So as it absorbs the energy it needs, it simultaneously creates a friendlier environment for less heat-tolerant plants below. Third, its root system will help hold the soil on the slope of the front yard, and will more effectively tap deep moisture than the shallow rooted plants around it, helping the soil stay moist and allowing better development of undisturbed soil structure. Fourth, its leaf-dropping habits will return useful biomass to me every year. Fifth, it serves as a relatively inexpensive teacher for me to learn more about cultivating fruit trees.

To multiply the utility of the dwarf pear, I put other plants in relationship with it. I planted some low-growing blueberry bushes around it. First, obviously, they produce delicious and healthy food, and a food that can be expensive to purchase. Second, they evolved to root shallowly in organic-rich soil on forest floors, so they are quite happy to live in the heavy mulch around the tree base (so the mulch is also stacking functions, doing double duty as a protective layer and as a rooting soil) and thrive in the sunny-but-not-vaporizingly-hot environment provided around the tree, as they like cooler soil. Third, both they and the pears make use of pollinating insects, so planting them close together increases the local density of honeybees and the like. Fourth, like the tree, as perennial plants, they will improve the soil in the long term by holding together a deeper, undisturbed soil structure. Fifth, as moisture-loving shrubs that don't like to drown in too much water, the tree helps keep them moist (tapping deeper water and bringing it to the surface via its roots and its transpiration) while at the same time providing a "sink" for excess water in the area. Finally, the blueberry bushes' shallow root spreads help suppress weed growth and grass from growing too near the tree base, which helps the pear tree, as certain grasses chemically retard tree growth.

To multiply the utility of both systems, let's put them in good relationship with me. I get exercise and satisfaction from planting and maintaining them, as well as super nutritious, homegrown, completely pesticide-free food - no food miles here, we're talking food-steps. Hugelkultur in both beds ensures greater health for plants, and a use for previously wasted scrap deadfall. I learn a great deal about the care and feeding of fruit crops, a skill I really want to develop. My landlord gets long-term value increases on his property, which encourages him to let me do more radical alterations to the yard. My neighborhood, a somewhat sketchy place at points, gets a small increase in beauty and stability. Wildlife get more places to nest and hide. Bees get food. A well-done system of interlocking, interdependent, multiply redunant (so the failure of any one element can't crash the works) stacked functioning systems not only builds a powerfully resilient permaculture system, but also creates momentum in a system - the better the design is, the less and less maintenance it requires to keep going.

So these examples  mostly show the physical side of function stacking, but it runs deeper, much deeper, than just clever aligning of inputs and outputs. It produces a change in perception, creating not only a vision that sees connections rather than isolated elements, but a tolerance for the inevitable chaos present in a system. I'm digging a hugelkultur bed, and keep turning up big pieces of fieldstone. Since I think in terms of stacked functions, however, this isn't a source of frustration and cursing the ground; it is a source of free stones, which I'll use to line beds, build garden paths, and so forth. Now I can be thankful that the garden is providing for another need, that I hadn't even thought of, so I don't spend time and money and gasoline going to buy premade generic paving stones at a store somewhere.

Good examples of stacked functions abound, and I'll be trying to tie in this principle as I discuss planting choices, bed designs, and so forth. Some additional links with good examples:

Stacking functions with plant guilds:

An example almost humorous, and almost divine, in its simple straightforwardness:

One of the most accessible-to-beginners-but-still-useful-to-experts examples, the Three Sisters:

Sunday, February 12, 2012

Nitrogen : What, Where, Why, and How.

All known life involves carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur, the ubiquitous CHNOPS of freshman biology. Any successful agriculture project must supply all of these, and any permaculture project must supply them indefinitely from local sources.

Luckily, as elements, none of the six materials "break down" in a system. The trick comes in making sure enough of it cycles through the system, in accessible form, without being lost or bound up irretrievably.

In this post, I'll talk chiefly about nitrogen, one of the largest issues for maintaining healthy gardens. Available nitrogen particularly concerns those of us trying to grow food crops, since capturing and transforming huge numbers of electromagnetic joules into food calories requires heavy feeding on the part of the plant.

Chemistry section, to ensure we're all on the same page - skip the blue text if you don't need it:

Nitrogen is a relatively inert, colorless, odorless gas in its default form. It's 78% of the atmosphere. It's also a critical component for every protein in existence, and remember that proteins aren't just muscle tissue and meat, they comprise the fundamental chemical architecture for all biochemical processes. No protein, no life. So, nitrogen's really important.

It's also bizarrely rare in the soil, given its incredible abundance in the atmosphere. However, gaseous nitrogen is in the form N≡N, that is, two nitrogen atoms triple-bonded to each other. This triple bond is extraordinarily stable, which is why gaseous nitrogen is really nonreactive. Therefore, it's also really energy expensive to crack open, in order to get access to the nitrogen for purposes like protein-making.

So energy expensive and complicated, in fact, that only a relatively small number of organisms can do it, using fancy things like iron-molybdenum complexes. There are a number of these microorganisms in the soil, some free, others symbiotically bound up to plant roots. They replenish available soil nitrogen, and in doing so help ensure the continued existence of all other life on earth.

The other source of available soil nitrogen is non-atmospheric. Things with available nitrogen, like animal poop and dead chipmunks and rotting plants, decay in the soil, and their nitrogen contents become available for other critters. If you are having dim memories of science class and "The Nitrogen Cycle" at this point, check out this awesome public domain graphic from the EPA:

This basic nitrogen cycle explains the introduction of sheep-pasturing to European farming - farmers figured out that land needed to be left fallow for several years after repeated plantings, or else pretty soon nothing worthwhile would grow on it (several years allowed soil bacteria and nitrogen-fixing plant symbiotes to replenish the nitrate supply.) On the other hand, just one season of letting sheep graze and poop in a field made it ready to go the following year - the sheep's guts liberate the nitrogen in the things they eat, and a lot of it ends up going out the other end. The sheep manure rejuvenates the field, making it suitable for heavy-feeding crops once more.

In the last century, we learned a number of excellent tricks to short-circuit this system. First, you can find a preexisting source of huge amounts of animal droppings, like coral atols in the geographical middle of nowhereusing the military to protect you if necessary, and then spend vast quantities of energy mining and shipping that stuff to your farm, where you dump it on your fields, Most of the urea and uric acid in it, the sources of nitrogen, get dissolved and washed away without doing much, but this kind of shotgun approach will certainly add nitrogen. Or, you can spend that energy in a slightly less insane fashion, and pull atmospheric nitrogen into usable forms (the Haber process), the doing of which currently consumes 1-2% of the entire world's yearly energy output. As an interesting historical tangent, Germany lacks access to any significant natural nitrogen sources (like guano deposits, or nitrate mines) for explosives, and without the Haber process, it would likely not have been able to wage World War I (the allies mind potassium nitrate, i.e. saltpeter, from Chile.)

So, although it's a neat set of tricks, they all depend on cheap readily available energy, which means they depend on fossil fuels. How can we build sustainable, non-petrochemical based, but still nitrogen-rich soil?
We just follow the standard permaculture protocol, "mimic nature with intention and forethought."

First, we ensure the presence of nitrogen-fixing plants, the ones whose roots house the symbiotic bacteria turning atmospheric nitrogen into plant-usable nitrates. This means legumes most of the time - beans, peas, alfalfa, soybeans, etc. Other nitrogen-fixers with multiple uses include clover, lupines, and rooibos. Nitrogen fixing plants which themselves provide food, fodder, beauty, and so forth, exemplify "stacked functions", a fundamental permaculture principle I discuss in another post, which boils down to "everything should exist in relationships such that, by being what it is, it performs multiple duties". If you have the luck to be in one place for the long term, a few awesome trees and shrubs are nitrogen fixers, among them black locust , the Persian silk tree (which we Southerners call a mimosa), and the Siberian seaberry.

Personally, I like to use clover for cover-cropping. Lawns should be a mix of grass and clover, which provides natural fertilizer and bee forage, and which was the case until Monsanto (having invented Roundup, which kills all broadleaf plants) poured millions into advertising to convince folks that a "real" lawn was nothing but a nutrient desert of narrowleaf grass. Many different kinds of clover can be used; they provide a pretty, nitrogen-enriching, bee-attracting crop, which can be intercropped with other plants.

Also, crop rotation - you do rotate crops, right? That's like the most basic and easy way to maintain soil health - crop rotations including legumes, and/or occasional "fallow" years of clover or alfalfa or whatnot, will replenish soil nicely, if you can afford to set aside space. Again, it need not be wasted; good choice of cover crops will mean your "unused" field provides plenty of beauty, bee attraction, and green manure. As I'm not big on plowing, I would stick to growing annual cover crops, and chopping them back before they seed, rather than just letting them run rampant then breaking up the soil network by plowing the whole works.

You can also include animals in your rotation, but I have no personal experience with that, so I will remain silent. I plan to rectify this lack of experience later, though. God knows I need more pygmy goats in my life.

Finally, you can replenish soil nitrogen using "waste" material. Remembering always that "waste" is a verb, not a noun - no material is inherently useless and extraneous, we just fail to use it - taking organic matter produced by your household, breaking it down, and returning it to the soil, is a basic method of maintaining soil fertility that humans have used for four thousand or more years.

First, of course, you compost. Kitchen scraps become dirt. I won't dilate on composting, as plenty of good web and book resources already exist to which I can't add much. I will put in a plug for trench composting, for its simplicity, utility, and easy combination with hugelkultur.

Second, take advantage of the constant stream (tee hee) of nitrogen-rich fertilizer you make. Yes, I am totally advocating peeing into jars, then dumping those jars onto your compost pile, or into plastic bags of leaf litter (to make easy homemade leaf mold over the winter, fall waste becoming spring mulch), or for direct application to plant beds once you've diluted it about 10:1. There is much more to be said on the subject, but I'll limit myself to quick bullet points. It's sterile, it doesn't smell once applied, it's gobsmackingly obvious and efficient, and after doing it for a few days, you really realize how, despite a third of the planet lacking reliable clean water access, we in the first world consider it normal to take energy-intensively purified water and piss in it, to the tune of 5+ gallons per day per person. This is why we cannot have nice things, humanity. It's an excellent function-stacking exercise - a waste, which you pay to dispose of, now becomes a free and abundant and infinitely sustainable source of useful fertilizer.

I find that an upcycled 1-gallon glass jar, the kind that apple juice often comes in, provides an easy to use urinal. I also admit to certain mechanical advantages of being male, in this respect. A bucket full of wood shavings or sawdust works even better, as it slows the breakdown of the urea in the urine into ammonia (urea itself is odorless; the metabolites from food and the breakdown of urea to ammonia in water give it the characteristic pee smell), as well as - stacked function! - providing a chance for the wood to "charge" with water and nitrogen, ensuring its speedy breakdown. If like me you have pets, or a spouse with sharp senses, a sealed glass jar prevents odor escape, and the glass won't absorb any smell. If you use wood chips, look for untreated wood, and make sure to thoroughly soak any kiln-dried (lumber) sawdust, before mixing it with soil, as otherwise it lacks the water for fungal and bacterial breakdown. Better still is peeing into a bucket of biochar, to "charge" it with ions and water, but biochar deserves its own post at a later date.

I'm also skipping over humanure, composted human waste, not because it isn't awesome (it totally is) but because I lack enough experience with it directly to add to the extant conversations on it. In the future, though, expect me to pontificate at length on the virtues of poop composting. In the mean time, make use of Milorganite, an idea so breathtakingly amazing that it's unsurprising that only one metropolitan area in the USA does it.

Saturday, February 11, 2012

Hillside Hugelkultur and Swaling, pt 3 : Bring in the rot, bring in the funk

You find "ideal" hugelkultur wood under piles of wet leaves on a forest floor, or partially submerged in slow-moving water, or under similarly damp, rot-producing conditions. One of the lovely things about a hugel-system, however, is its great flexibility and "fault tolerance." Pretty much any wood that isn't directly poisonous to detritovoric life will do fine, and the kinds of wood that are rot-resistant (cedar, fir, walnut, osage orange, black locust, teak, treated lumber) have much better uses than rotting. In fact, if you happen to have a bunch of walnut, osage, or teak lying around that you are thinking about using for hugelkultur, please stop, because every time you think about misusing precious wood like that, an angel gets put in a woodchipper.
Photo (c)
Even after chipping, angelic mulch
retains a visible glow, as seen here.
There are lots of excellent woods, though, many of which are common and easy to find literally lying around precisely because they aren't super durable, rot-resistant, or valuable. In fact, it's easier to just list the ones you should avoid. Unless you find them already decaying, I would avoid oak, cedar, cypress, or fir trees. However, it's a little more involved than that. Only the heartwood (core wood) of a tree gets the rot-resisting treatment; the outer layer of living sapwood resists rotting by virtue of being alive. So, the outer layer of any tree will generally rot pretty well, and younger, thinner branches / trunks / etc will be mostly sapwood, and therefore rot easily, so go ahead and dump them on the pile.

Since a moisture level over 20% or so must be present in wood for fungus to live, you need to use wood that's either fresh-fallen, or that stayed in moist conditions. To help the process along for some of the dryer pieces I had, I cut the top off of an old 55 gallon drum and built a large-scale compost-tea maker with the bubbler from an aquarium. Actually, at first I just put all the wood in the drum with water, but unsurprisingly that starts to stink after a bit due to anaerobic growth, which is the opposite of what I want anyway. So a cheap aquarium bubbler keeps the water oxygenated, and adding some compost to the vat creates a nice environment for getting the wood saturated and also colonized. None of this is essential, of course, but it seemed to help, and meant the wood would leach less moisture from the soil as it "charged" initially, reaching equilibrium with soil moisture (to avoid both dry dirt and dry wood, I'll also water everything a lot.)

So now I'm starting to stack the wood. It's all deadfall, especially easy to get since Hurricane Irene knocked down a lot of trees and branches. I also laid down dead leaves and other detritus. To build the mounds, I'll just continue to stack more branches, larger stuff on the bottom. I'll intermix it with dead leaves, the dirt I dug out initially, and aged manure. The aged manure comes from a farm rescue, where it is produced continuously as a side effect of taking care of lots of abandoned ponies, donkeys, and so forth. They pile it up on the edge of the farm, where it ages and breaks down into excellent rich soil amendment. It's not a necessary part of a hugelkultur mound, but given that it's not only free, but I'm helping dispose of what would otherwise be a "waste" product, and I can stop by the farm on the way home from a weekly out-of-town appointment anyway, it's hard to come by a more perfectly permacultural way to stack functions and multiply effects.
This is the first rough laying of the lower mound (the hillside will be two mounds, eventually.) You can see the large pieces of wood used to form the bulk of the lower level, as well as the sod I cut off the surface initially, which I flip grass-down and lay on top of the bigger trunks. As that material dies, it will create a pulse of available nutrients, particularly nitrogen compounds, to aid in decay of the big woody pieces. See my post on soil nitrogen for way more information on this topic than you probably wanted. The hose snaking through is a homemade drip-irrigation hose; it involves finding a discarded old garden hose, then drilling lots of tiny holes in it. For now, it's saturating the lower soil level before I add more stuff on top.

 Here's the first mound, construction complete. I've deliberately swaled the top edge of the mound, the create a path for excess runoff. It also provides a holding place for excess water, giving it time to absorb into the mound below it. Now, if you're particularly eagle-eyed and continuity-oriented, you'll notice that this mound doesn't run all the way to the end of the retaining wall. In fact, the area towards the retaining wall hasn't even been dug up. In reality, I did not do the extra digging to extend the mounding all the way until after this mound was complete, but that reflects not a careful and deliberate plan so much as an opinion on mound size which changed after I'd finished the first mound. Since this was my first hugelkultur work, I'd been conservative about dimensions, but as soon as I finished it, I realized it would quite nicely work if extended all the way to the far corner, rather than being unmanageable, and so that's how I would have done it to begin with were I to do the whole thing again.
It works! Water continues to behave in a manner consistent with my previous experience. At a low rate of flow, the mound simply swallows all water produced. Higher rates eventually saturate the immediate environment, fill the trench with water, and are absorbed over time. Higher still rates create exactly what I'd hoped, which is an small overflow stream moving away from the sidewalk and steps. Later on, this swale will empty into a depression at the corner of the retaining wall, a bowl-shaped area around a dwarf cherry tree, which will appreciate the water. I'll also be planting winter rye all over the swale, mounds, and so forth. Winter rye functions extraordinarily well for groundcover work. Scatter it in the late summer or fall, and it will solidly establish itself, resisting -30 F weather in the winter. In the spring, till it under or chop&drop it, before it sets grain heads, and it won't spread itself but will provide an excellent nutrient pulse after protecting your soil all winter long.

Here you can see the winter rye after a few days on the left, and after about a week on the right. The speed with which it germinated and grew I take as a good sign for the health of the new soil we're engineering. You can also clearly see the my seed scattering and raking did not produce uniform distributions, so I'll follow up with more seeds in the bald areas. You can also see in these pictures that the far edge has now also been dug up and hugel-ized, so the mound extends all the way to the far wall. These pictures also show, if you look carefully, how I laid pieces of scrap lumber along the bottom of the swale. This will provide solid footing, so that I can access all parts of the mound's crop cover, and it also helps to ensure that the swale doesn't became a miniature swamp if there are particularly torrential rains. The lumber will, eventually, break down, but as it's kiln-dried construction wood, it will remain relatively solid in this climate at least through next fall, by which time the mounds themselves will be solidly established enough that the earth will be much more resistant to erosion, becoming a mud puddle, and so forth.

Finally, this is the top mound, after its construction a week later. Same process, same results. Now, both mounds are seeded, swales are constructed, and on the top right of the photograph, you can see the new dwarf cherry that's below the curve of the hillside, at the corner of the retaining walls. All of the swales drain into its basin, where the hugelkultur mounds around it and its own thirsty roots deal with water overflows. At this point, it's just a matter of letting the mounds "cook" during the winter. The rye grass and the earth itself provide enough insulation that the deeper logs will stay above freezing for quite a while, allowing bacterial and fungal and other small life to begin turning logs into soil wealth. By the time spring rolls around, this area should be ripe and ready for planting. Also, having now observed for a while, I will be slicing the plastic wrapping off of the top of the retaining boards, because it is holding moisture against the wood. At the bottom I think it still serves a net benefit, keeping the wood from constant soil contact, but the top should be open to allow evaporation to keep the timbers dry.

Hillside Hugelkultur and Swaling, pt 2 : Hot diggity-dig

Once more onwards to adventure! Now the thinking parts have thought, and give way to the working parts working. To begin, I'll need to create deep enough trenches to lay in lots of rotwood and soil, without creating huge barrow-mounds in my front yard which I would then have to explain to my landlord.

I'll actually jump a little ahead, to give more insight into our "uphill battle" (do you get it? Hopefully you can keep reading despite your laughter.) On the left, you can see the depletion of this dirt, which isn't yet deserving of the sacred title of "soil". It's empty enough of organic richness that, turned over with a shovel and exposed, it dries to gritty powder in less than an hour, except where the clay concentration is high enough (there it dries to caked, baked mud.) We're looking to build a depth and wealth of soil such that turning a shovelful over will yield dark, damp, richness, smelling of humic acid and soil fungus. So, we'll need to create lots of pockets and niches that will capture and hold water, nutrients, and so forth, and we've got to feed the whole works with some rich organic base materials. Even if we wanted to waste ourselves carefully watering and babying marginal land like this, it will never be much without food and lodgings for the web of life that transmutes dirt to soil.
Step one, then, is easy : DIG. Thankfully, I like to dig, and the soil isn't very hard. The scrap of plywood you can see serves as a stable place for me to stand. I'll be digging down a total of about 18 inches, although it will shallower towards the stone wall at the bottom. That will still leave me with hugelkultur mounds which, due to gravity, may want to fall over into the roses lining the driveway, so I'll need some sort of low retaining wall. The remains of an old aboveground pool I found in the garage will furnish a bunch of regular, strong, enamel-coated hollow metal pipes which would be great anchors for a long low wall, which in turn will be made out of untreated fir 2x10x12 pieces of lumber. In retrospect, I could have made the entire wall out of nothing but free scrap 2x3s. It turned out fine, however, because I ended up using most of the fir I'd purchased for other projects, rather than building the much-larger-than-actually-needed retaining wall I initially envisioned, which would have been about 3' tall and a real pain in the neck to put together.

 The lumberyard in whose dumpsters I am privileged to root around provides a lot of heavy plastic wrapping, the kind used to secure things like appliances and piles of boards to their shipping pallets. The biggest issue facing the fir I'll be using as a retaining wall is the constant contact with the ground, since I'll in fact be partially burying it to prevent soil and water from flowing underneath it. In an attempt to slow the decomposition this would bring, I'm wrapping the fir board in some of the plastic. This of course also means any moisture that does get in will be held in, rather than being able to evaporate, but I'm guessing that will be a much more minor issue than the pooling water and wet soil it would otherwise contact. The driveway performs admirably as a staging and assembly area for this assembly.

The plastic-wrapped board gets snugged down into the extra-trenched socket I've dug for it, and the metal poles will be driven in behind it, pinning it between the deep-rooted poles and the heavy cement lip of the retaining wall. This also may help with slowing rot of the border, as it means that the water trying to pile up against the board will be able to flow under it and down the inside of the wall.

You can see the board in place, with one of the scavenged swimming pool support poles hammered into the ground behind it (the white pole with the black top.) This photo also gives a good sense of the lay of the yard, the steepness of the hillside, and the extent to which I'm digging into the top layer of organic matter. You also see the constraints I'm working with - the stone retaining wall, the cedar tree, the sprawling rose bush, and the cement steps. I'm seeing what kind of abundance I can coax out of the small patch they border.

This shows both the  poles and scrap timber I sledgehammered into the dirt to pinch the retaining board between posts and the wall's inside edge. You can see that my retaining wall is discontinuous; look near the hammer handle and you can see that the stone retaining wall has begun to shift with its century of New England weather, so my wall has to follow it. This is also why I didn't just run the posts in front of the wooden retaining wall and let the dirt push against the other side - I want to minimize further direct pressure on the stones of the wall, which are already bulging.

 An evening shot, with my flashless cameraphone. The weird ghostly-looking stuff at left is scrap cardboard (white patches on the cardboard reflect a great deal more incident light, and show up neon-glowy.) Nothing waxed, or still with tape on it; the torn pieces of cardboard provide a base layer of water sponging, a future mat of worm-penetrable, fungus-penetrable sogginess, and an easy meal for cellulose-chewing soil bacteria. Also, it's a nice way to upcycle boxes that are too beaten up for re-use. If you look closely, you can also see that I've laid down boards and backing poles all the way to the corner of the retaining wall. Tomorrow, we start with the rotting stuff.

Wednesday, February 8, 2012

Hillside Hugelkultur and Swaling, pt 1 : Concepts and planning

"Are you looking for firewood? Y'know that stuff won't burn right, it's all soggy and rotted!"
"That's okay, I'm deliberately collecting rotten stuff."

- The generalized form of a conversation I hold every time folks find me loading their waterlogged curbside junkwood, sacks of yard waste, and so forth into my vehicle.

     As a result of permaculture training this past summer, the concept of hugelkultur firmly lodged itself in my gardening outlook as a beautiful blend of most everything I like in terraforming - low impact, high yield, zero cost, immediately practical, and conducive to long-term positive change. Although the link I embedded gives a long and excellent overview of the topic, the shorter version is this: lay down a bunch of rotting wood, dump soil on top, plant things. The rotting wood, once "charged" with water, provides a slow and constant source of water, minerals, fungi, bacteria, microorganisms, soil insects, and so forth to the soil and roots around it, acting as a giant goody-sink that plants can draw on for years as it slowly decays. It also helps to effectively sequester the carbon bound up in the wood, as much of it gets turned into soilborne organisms and soil, rather than reverting to atmospheric carbon dioxide, its much quicker fate if it just breaks down on the surface, or gets burned.
     By some calculations, the amount of carbon sequestered in soils worldwide, as abiotic carbon, soil organisms, slow-rotting material, etc - weighs in at 2.7 trillion tons, whereas all of the living matter on Earth makes up only 575 billion tons, most of it locked up in trees. As it turns out, deforestation ends up being a greater problem due to soil erosion, and its consequential loss of soil-bound carbon, than due to direct loss of the trees. This makes hugelkultur completely awesome both to jumpstart rapid nutrient-fortifying, carbon-banking, sassypants-delicious soil farming, and also because the mounding system hugelkultur lends itself to allows for easy earthworks, as you can lay the mounds down in lines to divert, capture, and better utilize water flow in an area. This ties back into the manifold benefits of large-scale carbon banking in the soil, a major one of which is increased soil capacity for water storage (just think of how moist, alive with life, and earth-smelling a handful of rich black loam is when you scoop it off the floor of an old forest, and compare that picture with a handful of beach sand - the major difference comes down to total carbon present.)
     However, talk is cheap. So on to implementation!

Genesis point
This shows my starting point. This small hillside in the front yard faces northeast. It's growing nothing, as you see, but patchy grass; the soil has no depth, there is nothing to hold the water runoff, and it spends most of the day baking in the sun, except when it's shadowed by the cedar tree at the top which helps pull water and nutrients away from anything trying to grow. So, an excellent place for serious soil building, as well as a spot just aching for earthworks to better use the rain and snowmelt this spot currently just sheds. For reference, it's about 20 feet long, and six feet up the hill, at a slope of about 40 degrees.

Dead dead dead dirt.
So, we begin with the thinking and data collection. I already mapped out the basic landforms and local climate, and a shovel test keeps with expectations - the "soil" is a half-inch of dry crumbly stuff, on top of clayey stuff underneath. Unlike much of the yard, this doesn't show signs of having been loved and utilized at length in the past, it just looks like crappy, paper-thin yard dirt. My plan, therefore, is to build up hugelkultur mounds to start building organic depth in the soil (and building something deserving the name "soil"), while also shaping the mounds to act as runoff-blocking ridges. The ridges create small swales (low lying, moist areas) behind them, and the swale's water will be soaked up by the mounds, as their wood innards can absorb, and will need initially, large amounts of water to "charge". Careful shaping of the mounds also ensures proper runoff channels in case of torrential rains. So, goals here:
  1. Build soil
  2. Catch & utilize runoff
  3. Minimal financial investment
  4. Don't abuse landlord's amazing willingness to let me dig up the yard
Goal #4, in particular, dictates digging down more than piling up, so that the height of the mounds will be less obvious, less obtrusive, and less likely to get immediately bulldozed as soon as we move out. My next post will start, therefore, with the digging of graves trenches.