A box of tools – then and now

April 2, 2021

At some point over the winter I stumbled onto a mention of the Mastermyr chest on the web, and marveled at the similarity of thousand-year-old Viking tools to hand tools today:

Not long after, I was puttering in the workshop with Z, who was fascinated by and kept pulling tools out of my own wooden toolbox, so I decided to pull everything out, dump the sawdust and drywall screws, and take my own version:

It appears that the Mastermyr box owner was a locksmith, and I imagine folks in that trade as being clever, thoughtful, and handy. It’s fun to imagine a Viking craftsman time-traveling into the present and wondering at 21st century tools; most I imagine they’d figure out quickly, even if they weren’t a thing back then (bubble level, chalk line, hex wrenches). The stud finder and the digital multimeter might take some explaining. Just imagine the fascination of the Mastermyr craftsman on figuring out a staple gun – or a pneumatic framing nailer!

I’ve been enjoying a trove of practical history blog posts by a classical historian named Bret Devereaux (here’s a series about iron and ironworking). In some ways technology is surprisingly stable (e.g. pliers, hammers); in others it changes very quickly. It seems that one of the blacksmith’s most time-consuming tasks back in the day was making nails, and when I was growing up a big part of carpentry was driving large galvanized nails. Then along came pneumatics and high-quality structural screws, and recently my dad has been trying to figure out what to do with hundreds of pounds of leftover nails and spikes that it may never make sense to drive.

Richard Scarry innovation – more on hydraulics

April 1, 2021

The recent Richard Scarry post gives an example of disruptive innovation that can be enjoyed by a 2-year-old. But for a professional innovator it’s interesting to think about how it happened and why it happened then.

Christensen described how hydraulics burst on the scene in the middle of the last century and quickly displaced cable-driven equipment to dominate the market for excavation equipment. But hydraulics in some form had existed for thousands of years. Beyond the obvious dams, irrigation ditches, grist-mills, and the like, according to Wikipedia the Romans had piston pumps and used them for e.g. firefighting. Pascal figured out hydrostatics in the 1600s, and a fellow named Joseph Bramah invented the hydraulic press in the late 1700s (Bramah also invented the flush toilet). In the 1900s hydraulic power distribution briefly became a thing in the UK, before being eclipsed by electricity. The famous Tower Bridge in London built in the late 1800s was hydraulic-powered (literally – the working fluid was water), and apparently that system operated into the 1970s.

Mechanical power transmitted by cables and pulleys is also thousands of years old, dating back to at least ancient Egypt. Ships made extensive use of pulleys, blocks, and tackle, to the extent that the British navy’s need for blocks led to one of the earliest forms of mechanized manufacturing. On land, the human-powered treadwheel was used to build cathedrals and other works, and presaged the digging machines that Christensen wrote about.

I haven’t dug deeply into the history of manufactured hydraulics, but I suspect that the sudden breakout of hydraulic technology in excavation has more to do with the pumps than the pistons. It stands to reason that piston-cylinder setups that can seal properly and take significant pressure would arrive at around the time as piston-based engines, based on the necessary precision of boring machines and sophistication of oil seals and the like. But in order to make practical use of hydraulics for digging machinery, you have to be able to deliver significant energy to the hydraulic cylinders, and to do it in a mobile machine (as opposed to stationary works where you can tap pressure off a dam or something) you need compact, robust, high-pressure pumps. Most of these seem to be some form of gearpump, which in turn requires precision in machining the complex meshing surfaces, an art and science that surely advanced massively in the 20th century due to automotive transmissions, aircraft, and general engine-engineering. As we have learned the hard way in pedal cider experiments, high shaft speeds are important to getting decent efficiency in hydraulic pumps and motors, given that leakage flows are driven by pressure, so engines had to speed up to a certain point, and gears had to get precise enough to allow that to happen.

By comparison, larger, cruder open-gearing systems driving drums and cables seem more compatible with older, lower-speed engines, and generally requiring of a lot less precision – not to mention that when all this was getting started, lubricating oil was harvested by hand-hunting whales on the open ocean, so it would not be attractive to use it as the working fluid for large, crude, leaky piston systems.

Putting all this together, it doesn’t seem surprising that cable-driven machinery dominated in the age of steam and early internal-combustion engines, but within a few decades after high-speed engines came of age an entire industry would spring up around compact, high-pressure hydraulic drive systems. And in the time since Christensen wrote that chapter, hydraulics have continued their run to the point where many small tractors and other light construction machinery – where smoothness and durability are more important than pure energy transmission efficiency – have no direct drive mechanisms at all. I remember first being struck when looking ‘under the hood’ of Dave’s small bobcat excavator and realizing the whole thing was run by one big pump.

The cables-to-hydraulics story is an easily-visualized and personally interesting example of a larger set of phenomena in technology and innovation, where a certain technology platform dominates for a long time, despite the presence of minor competitors, and then some other technology platform goes on a tear and displaces both the previously-dominant platform and all other competitors to become the new incumbent. It’s pretty clear to me that the key to understanding this is positive feedback, or virtuous cycles of economies of scale, cost reduction, profit, and reinvestment in innovation. I hope to write a post or two about these virtuous cycles soon, specifically on the striking recent growth in silicon solar cells and lithium batteries.

on the Texas energy catastrophe

February 21, 2021

Like most people I’ve watched the Texas power grid collapse and the resulting cascade of failures with dismay, though perhaps with less shock than is typical. The modern way of life is utterly dependent on copious and freely-flowing energy (85% of it from fossil fuels), and ordinary people take that for granted to a degree that is maddening from the perspective of an energy engineer.

This morning the New York Times has an article about people in Texas who didn’t lose their power, but are facing 5-figure monthly electric bills because of the specifics of the rate plans they signed up for in the de-regulated market. Apparently among the over 200 competitive plans in the state, some have the schtick ‘wholesale plus $10/mo’; when wholesale rates railed out at $9/kWh, those plans duly passed the cost on to the homeowners. (The average home uses about 30kWh per day; surely big Texas homes in a cold snap use much more.)

Besides falsely blaming renewables for the state’s failures, the governor is now promising to protect Texans from that market functioning as intended – from the same article:

“We have a responsibility to protect Texans from spikes in their energy bills that are a result of the severe winter weather and power outages,” Mr. Abbott, who has been reeling after the state’s infrastructure failure, said in a statement after the meeting. He added that Democrats and Republicans would work together to make sure people “do not get stuck with skyrocketing energy bills.”

I believe it was Amory Lovins of the Rocky Mountain Institute who said something to the effect that “Markets are designed to be Efficient, not Sufficient,” and this is a great example of that. The provision of affordable, reliable, non-planet-destroying energy to over 300M Americans and nearly 8B humans is not primarily an economic project, it is primarily a technological project. Economic systems are technology, markets are an extremely powerful tool to lubricate the inner workings of that project, and financial tools could be an engine of transformation (e.g. a global carbon tax), but by themselves they don’t magically solve much of anything.

The power grid is practically the textbook example of a natural monopoly, at least for transmission and distribution, and the trouble in Texas obviously started with a lot of equipment (mostly around natural gas) shutting down in conditions it wasn’t designed to run in. The modern electric grid operates essentially ‘just in time’ without significant energy storage at any step or scale. Most homes don’t have backup systems and aren’t very well insulated; pipes burst below freezing and homes flood, and from there things go to hell pretty quickly.

The wildest thing about this story is that $9 per kWh is still a bargain in human energetic terms. As I wrote in Energy Enlightenment and the better angels of our exotherm, an average human at hard labor (say pedaling to power an apple cider mill) can only produce about 1kWh per day. A human diet of 2000 dietary calories per day is only 2.3kWh, and this puts a hard ceiling on what a person eating that much could deliver on an ongoing basis. The amount of energy that typical Americans take utterly for granted is a ginormous thundering torrent in absolute human terms. If more people realized this, they might refocus some of their pandemic home improvement efforts on superinsulation, backup systems, self-generation (i.e. rooftop PV), and modest onsite energy storage – likely some combination of firewood, propane, and lithium.

The problem of ‘lifestyle’

February 8, 2021

I hate the word ‘lifestyle’, at least in relation to anything that matters, because it trivializes that which should not be trivialized. Much like Consumers, it is a word that slips in easily to replace something harder and more important.

Collectively, humans have colossal power – including the ability to defeat (or not) viral contagion and transform, devastate, or renew landscapes.  In the fossil fuel era, we have materially altered the temperature of the entire surface of the planet in a few short decades, and are creating in a century an extinction event that will be visible over the sweep of billions of years. We also have choices, and so we have responsibility for our actions.  “They” did not do these things, WE are doing them – you and I do them every time we pump gas, eat a steak, or step onto an airplane. While each person’s individual contribution is miniscule, they add up exactly to our collective impact – there is nothing else.

Engaging meaningfully with global environmental challenges requires scientific literacy and the ability to see past appearances.  Carbon dioxide in the atmosphere, mercury in fish – these things are literally invisible, and undetectable without the tools of science.  And the chains of causation between my everyday actions and my infinitessimal contribution to them are invisible likewise. One must dig under the surface to understand them.  But Lifestyle is all about appearances.  It points attention at cultural signifiers, gloss, and status, not the sinewy reality of material and energy flows and actual impacts of behavior.

At some point in college I did a quantitative accounting of my carbon footprint, and on many fronts I did well – living in a cooperative community with nearly 30 other young people, eating a vegetarian diet, riding a bicycle as my daily commuter. But I was surprised to find that well over half of my impact came from frequent car trips to the White Mountains of New Hampshire to go hiking – despite driving a relatively efficient vehicle for the time. This took me aback, and got me thinking harder about actual impacts as opposed to easy perceptions of what constituted “environmentally-aware lifestyle activities”.

Often I have lamented here when the superficial gaze of the New York Times style page lands on rural life and finds improbably clean chickens clutched against pristine leather jackets. It’s not just that this is precious and inauthentic, it is actively leading us astray.  The combination of innumeracy and a focus on style over substance is the same instinct that causes people who travel by air to concern themselves with plastic soda straws.  A ‘rural lifestyle‘ that occupies prime farmland, consumes agricultural inputs, and releases agricultural methane without actually producing agricultural goods in a low-impact way is no more sustainable than flying across oceans to go hiking.

Much is written about the influence of money in our politics, and to be sure it is malign.  Apparently the 2020 election cost $14B, which seems like a huge sum, but in the context of over 300M people it is amazingly little – only about $40 each – the average American spends far more on energy every week.  Recent violent outbursts acknowledged, the abiding reality is mundane complacency, with smokestacks and tailpipes belching all the while.  In this context, how we use our dollars day in and day out is much more impactful than our voice or our vote. 

The pandemic has made it clear that there is a large class of people who are deeply, pathologically allergic to the idea that they are responsible for the effects their actions have on others.  But responsible they are, and responsible we are, the childish tantrums of adults notwithstanding.  Whether it’s invisible viruses spreading in close-packed rooms or ten-cylinder engines roaring freedom on a wide-open highway, we are bound together in the fabric of a reality much deeper than the gloss of fashion or the ring of tinny internet rhetoric. But “Lifestyle” says it’s all good – just a matter of freedom and fashion or personal taste.  Will it be “My lifestyle is to minimize air travel and grow vegetables”? Well then, good on you!  Or how about “My lifestyle is to jet-set around the world hunting endangered species”  Well then, good on you! If how we behave is just a matter of personal style and preference, these choices are equivalent.

These choices are not equivalent.  I believe we have a moral obligation to act as if our actions matter, and life should be about far more than style.  I want people to learn about the physical, quantitative effects of our choices, reflect on them, and change our lives so we have less negative impact on the planet, and more positive impact on our communities.  In doing this, and in keeping with the great coming together that is needed in the wake of the past few years, I hope we can pay less attention to “Lifestyle” and more to the actual gallons and miles and gigatons of reality.

The Innovator’s Dilemma: evidence from Richard Scarry

February 7, 2021

The Innovator’s Dilemma by Clayton Christensen is a classic of innovation literature. I was introduced to the basic ideas by Ely Sachs, inventor of one of the major types of 3D printing as well as two impressive kerfless silicon wafer manufacturing technologies, and I finally read it a year or two ago. A major theme is that established dominant market players are good at ‘sustaining innovation’ to incrementally improve their products in service to existing customers, but are lousy at ‘disruptive innovation’, applying new technologies to adjacent, emerging market segments. More typically a new technology is incubated by startups in adjacent markets until it matures to the point where it (and the startups pioneering it) rapidly crush and replace the older technology.

The meaty academic example he uses in the book is the hard drive industry, but chapter 3 gives much more tactile and approachable example, that of mechanical excavators. As the story goes, in the steam era an impressive industry grew up to produce cable-operated, forward-scooping excavation machines (‘steam shovels’) to serve the construction industry, and the leaders in this industry successfully navigated the transition from steam to gasoline to diesel-electric drives in the period from the mid-1800’s through 1950. Then, between the 1950s and 1970s they were suddenly crushed by the rapid emergence of new companies building hydraulic-actuated equipment. Hydraulics established itself in the niche of small, maneuverable tractor-based digging machines used by building contractors to do utility hookup work in the massive post-war building boom, and then quickly scaled up, switched to track-based drives, and grew to all but eliminate cable-driven shovels at the large end of the market. I remember as a kid seeing old rusting cable-driven shovels scattered around, and I remember in the early 1980’s that the cellar hole for my grandparents’ house was dug by a local guy with a yellow backhoe, and I remember tracked hydraulic excavators gradually becoming an everyday thing, but I never put it all together as an example of disruptive innovation.

One of the neat things about my mother being a kids’ book author is that she has an infinite collection of old picture books, and Z has been the beneficiary of that. One of his favorites is Richard Scarry’s Best Word Book Ever, originally published in 1963. There’s not much electronics in it (he wouldn’t recognize the television set even if we had one, and we haven’t bothered to teach him what the telephones are), and the cars look a bit funny with tailfins and the like, but otherwise it’s surprisingly mostly relevant. So in light of the excavation example in Christensen’s book, I was interested to see how different things are on the ‘Work Machines’ page, showing construction equipment:

The cable-driven ‘shovel’ is the most prominent piece of equipment in the lower left. There is only one machine that’s clearly hydraulic, the clunky-looking yellow ‘tractor shovel’ in the upper right. The apparently chain-driven mobile ‘bucket loader’ on the right is a piece of equipment I’m not familiar with at all, and it’s not clear how the ‘tractor scraper’ at upper right is actuated. The most interesting thing to me is the bulldozer in the upper left, whose blade appears to be raised by a cable-pulley arrangement rather than by hydraulics. I can dimly remember from when I was a kid that bulldozers often had cable winches on the back, but I never put the pieces together that originally the winch would have been used to raise the blade, and when I asked my dad confirmed that this was indeed the norm back in the day. Having done a moderate amount of earthwork using small equipment, I can imagine how the inability to apply down-pressure using the blade would be a major limitation in the usefulness of a bulldozer, so hydraulics must have been a revelation when they came along.

According to wikipedia, the Fresno scraper was invented in 1883, and it was a major innovation – for millenia the state of the art had been picks, shovels, wheelbarrows, and carts, but in the fevered pace of the industrial era the Fresno quickly evolved into the tractor scraper, dozer, and other modern equipment. When I was a kid my grandparents had a small yellow John Deere bulldozer; it was kind of a joke that it belonged to my grandmother, because my grandfather got it for (himself for) her birthday. They used it for clearing and firewood-harvesting around the land, and it was generally underpowered and marginal for our needs. The blade angle was manual, and by the time I was old enough to run it one of the steering brakes had stopped working, so it was like one of those old cheap RC cars where the way to go left was to go backwards and turn. But the blade raise/lower was at least hydraulic, and on contemplating this history I have a new appreciation for it. It’s remarkable how much even a mundane-seeming area of technology can improve in a fraction of a lifetime!

2020 experiments with staple crops

January 17, 2021

As the spring of 2020 took its pandemic-crimped shape and grocery stores emptied of various basic items, I resolved to expand our plantings as a sort of Victory Garden for the times. In the previous post I described reclaiming a box of sprouted red potatoes from the basement in the early spring, which produced some good-sized tubers before the Fourth of July, and we had a good harvest of our main potato crop as well. I also experimented this year with other staple-type crops; results are summarized below.

The spot I used had been a chunk of gently north-sloping land alongside the driveway. Years ago I put up a sign at the end of the drive saying ‘wood chips wanted’. Nothing happened for several weeks, and then suddenly about 100 cubic yards of chips showed up one afternoon, from a crew that was clearing somewhere nearby. We gradually pulled from the pile, a wheelbarrow or trailerload at a time, to mulch the garden and other plants around the place, to the point where the piles diminished and rotted and started to grow up in weeds and sod, So this spring I spread the remaining chips around, tilled the area with a 5′ PTO tiller, and fenced it in, enclosing perhaps a thousand square feet or a bit more. The underlying soil is perhaps a foot of very finely packed silt overlying a prodigious depth of remarkably coarse beachlike sand.

Dry Beans

We’ve always gone through a lot of black beans, and I remember when I was a kid we grew dry beans of various types (including large spotted ones I remember as ‘Jacob’s Catalog’ beans), and even had an 8×8′ square room to hang and dry them in a shed that was known as ‘the bean room’, so on the spur of a moment I figured to give it a shot. For seed I used the organic black beans we buy in bulk, first soaking a small handful (maybe half a cup?); then I planted a 25′ row of newly turned ground. I didn’t have bean inoculant and didn’t think to put on the clover inoculant that I had, so they were on their own for nitrogen fixation. They didn’t grow spectacularly by appearance, but did set pods and dry down partially in the row. As they started to die back I cut them off with pruning shears to avoid pulling out soil and rocks (as suggested by Carol Deppe), tied them in bunches, and hung them under a porch to dry further. Later in the fall I thrashed/threshed them in a metal trash can, winnowed with a box fan, and recovered pretty much exactly a quart of nice black beans, weighting out at 716 grams. If the row spacing were 2.5′, this corresponds to 123 grams per square meter or 511kg/1100lb per acre. Online I see the label on a bag of Goya dry black beans, stating the energy content of black beans as 150kCal per 44 gram serving, and at this rate my little row turned in a productivity rate sufficient to feed 2.3 adults per acre. In a national comparison, it appears that the biggest bean-producing area in the US is in northeastern North Dakota, and this source shows ~1500lb per acre dryland or ~3500lb/acre irrigated in North Dakota (using narrower row spacings and presumably plenty of soluble Haber-process nitrogen). So 1100 lb/acre from a spur-of-the-moment experiment yielding subjectively scrawny looking plants doesn’t seem like a bad result for a first try. One of these cold weekends I’ll make a nice pot of chili using them and some of the frozen corn we grew.


The main expansion of our staple crops this summer was in corn. After a successful experiment several years ago growing fedco’s Wapsie Valley field corn in a patch inside the orchard fence in Five Islands, I resolved to plant a sizeable patch in the newly enclosed garden area of about 750 square feet. I also tilled and reclaimed our old strawberry bed, amounting to about 600 square feet, which had gone over to grass and weeds, and we planted this in sweet corn. Both sites sloped gently but consistently to the north, so we arranged the rows diagonally cross-slope with a gentle curve to match the lay of the land, which turned out to be a good move. I planted the field corn after soaking the seeds and letting them germinate a bit, and used a 32″ row spacing. I don’t remember the timing, but it was a bit after the oak leaves were the size of squirrel’s ears. When the plants were 8″ or so I thinned them in the rows, though perhaps not enough. For side-dressed fertilizer, an experiment I alternated rows between our own screened compost and ‘pro-grow’ commercial organic fertilizer; I don’t remember the dosing but I did read the bag and do some math. For the compost I put maybe a drywall bucket on each row. As the plants grew I ran the BMX-bike wheelhoe cultivator down the rows and raked the loose soil up around the plants in rows, which turned out to be a good thing.

Here’s a photo of the field corn at about the point where it was emerging; the salvaged potatoes are in the foreground along with some extra broccoli in pots, and the single row of beans is between the potatoes and the corn. The sweet corn is in the lower bed hidden behind the near solar panels. The window sash tents have summer squash under them.

Kelsey planted a big crop of sweet corn in the lower bed, three different maturity types that I bought at the feed store in Windham. She used perhaps a bit wider row spacing and leaving the plants closer together within the rows, and it worked out fine. I believe I dosed the sweet corn with both compost and pro-gro, though not a particularly heavy dose of either. It was all knee-high well before the fourth of July, and as needed I irrigated both patches overhead using the oscillating lawn sprinkler arrangement I described in the previous post. Here is the sweet corn from the north, with the field corn between the solar panels and the back of the greenhouse; the tall stakes that accept the oscillating sprinkler setup are visible in this and the previous photo:

While overall the summer was dry, sometime just as the sweet corn was starting a tropical storm blew in, with several inches of heavy rain and a strong southeast wind. Here the differences between the field and sweet corn became apparent. While a handful of stalks of the Wapsie Valley corn were leaned over into the neighboring row, the stand was largely intact. On the other hand, large swaths of the sweet corn was lodged almost all the way down in a chaotic mat, though the plants gamely re-oriented their tops vertically and still produced a decent crop. There were a few small washed spots from the massive flow of rainwater, but nothing a shovelful of soil couldn’t patch – all in all the terraced rows did their job and preserved the soil. I thought I planted plenty deep enough, but the field corn put out weird alien-like root fingers just above the soil even though I hilled it up substantially with a leaf rake a couple times; it occurred to me that if I had planted in slight hoed depressions those strange root things might have taken hold and further stabilized the stalks.

Like strawberries, over the course of the harvest the sweet corn went from a revelation to a treat to a bounty to a chore; To Everything There Is a Season. We ate plenty right out of the pot, kept cooked ears in the fridge for a snack, and froze several gallons of cut kernels for winter. As each variety wore itself out I cut it down in place (using a sharp chef’s knife as a machete; though I lived in fear of hitting something hard an nicking it, in practice it worked well) and raked up the pieces for the compost pile. As summer went on the field corn started to brown up and the ears to dry; at some point Z and I started harvesting a row at a time into marked paper bags for the fertilizer experiment. I dried the ears on the attic floor, and cut and piled the stalks so I could replant the area in rye and red clover. Chopping them became a chore; I ended up laying them in the back of the truck with the thick ends backward and attacking the pile with a brush knife on a Stihl clearing saw. This turned out to be loud, heavy, nerve-racking work, as I was loathe to hit the bed or tailgate with the spinning brush blade so I had to repeatedly pull the mass of wet stalks backward out of the bed once I’d cut it off short. It would have been preferable to either chop and rake them in the field like the sweet corn or get a functional chipper/shredder (more petroleum, or maybe REbus?), but I got it done, and it did result in a large compost bin that steams on frosty mornings from the life within. Here we are gathering the knife-cut sweet corn, headed for the compost:

Regarding the fertilizer experiment, at one point when the stalks were around head-high there appeared to be a visible difference in height and color between the compost and commercially-fertilized rows, but this became less apparent later on. It was more apparent in the crop yield, where particularly in the middle of the bed the ears seemed smaller and wimpier in the compost rows. After leaving the ears to dry in the attic until early January, I reassembled Holly’s antique cast iron corn sheller to the pedal power stand and shelled out the corn, one row at a time so I would have some datapoints to compare the compost to the ProGro. One problem with the sheller is that kernels fly off at high speed in every direction; in contrast to the hastily-assembled setup we used at Cider several years ago, I put a bit more time into it. I used a thick flitch of applewood for the structure, and made a decent see-through enclosure using scrap 8mm twinwall polycarbonate left over from the greenhouse project. (The grain mill is in the foreground; the idea is that the plywood platform can be slid off the T-slot frame and reversed to mill flour, but in the end it’s kind of cluttered so I will probably make a separate plywood base for the grain mill)

The new setup allowed me to capture the grain from each row and clean out the sheller between rows. I then weighed using a kitchen scale and put all the data in a spreadsheet. The overall yield of the plot was 28.1kg for 729 square feet of garden area (plus 1kg of chicken-grade grain and 6kg of cobs). The yield of prime grain corresponds to 1680 kg per acre overall; however there was a marked difference in yield between the compost rows and the ProGro rows. The rows were not all the same length, so I normalized per foot of row, and calculated on an area basis (the row spacing was 32″). The compost rows yielded an average of 1250 kg/acre, while the ProGro rows yielded an average of 2120 kg/acre. According to a Bob’s Red Mill package, cornmeal yields 140 Calories per 38 grams; at this rate the corn plot grew food at a rate sufficient to feed 8.5 people per acre; the breakdown was 6.3 people per acre for the compost and 10.7 people per acre for ProGro. It appears that the national average corn yield (heavily fertilized) is around 180 bushels or ~4600kg/acre, able to feed 23 people per acre (if people ate corn rather than pork and whatnot).

The difference in yield between the compost and ProGro rows is clearly visible in the graph. (The rows run more or less east-west and the first row is to the south; the 10th short row got both compost and ProGro). There seems to be a general trend of lower yield in the middle of the bed for both fertilizer types; this could be related to the soil, which was not entirely uniform, or possibly greater sunlight at the edges, though the first row to the south had nearly the lowest yield. That row may have been competing with the dry beans and some sunflowers the kids planted to the south, or it may not have been sufficiently reached by the sprinkler, or who knows what. There were a couple rows in the middle where the yield on the compost rows was noticeably poor; many plants did not produce an ear and those that did were gimpy and weird. Given that this was unimproved soil that had been under a giant pile of woodchips for a decade, I am going to assume some deficiency in the soil that wasn’t compensated by the fertilizer. I shelled out the corn on a rainy day so the weights above are before winnowing; on the other hand I went at each ear pretty scrupulously with a spoon gouge (hi Brandon!) to eliminate any partially chewed or moldy kernels, so there’s probably another kilo or two I still need to sweep up off the shop floor and grind up coarsely for the neighbor’s chickens.

I thought perhaps I didn’t thin ruthlessly enough given the limited fertility; however there’s no sign of this in the data; if anything yield seems to be higher with more plants per foot in the row, though if you squint at the data you could imagine that row 10 was spaced too tightly.

I think I remember Gene Logsdon’s book saying that 100 bushels per acre was a reasonable goal for open-pollinated organic corn, and we’re at 66 average on the first try. Given that this was raw soil and we haven’t done so much as a single soil test or cover crop, I’m not going to feel too bad about the subcommercial yield here. Pretty much every part of the process of growing field corn is fun, particularly the shelling, which is amazingly easy and satisfying – I’m confident that with one person to pedal and one person to feed, the bike-powered sheller could process well over a ton of grain per day. I expect I’ll come back to growing field corn from time to time and keep puttering with the techniques.

Winter Rye

In another unplanned staple crop experiment, after having some grading and smoothing work done around the yard the previous summer, I planted rye and clover in the fall of 2019 to stabilize the soil for winter. There were two small plantings, one of southerly aspect but heavily shaded by trees, and the other more open but steeply sloping to the north. I had meant to mow down the rye in the spring, but as the events of 2020 unfolded with flour shortages in the groceries I decided to let it grow, and at least in some places it made a nice-looking stand, though thin and weedy in others. After it browned in midsummer I cut it down with my grandfather’s scythe, and gathered the cut stems in a large tarp which I wrapped and hung with light rope from the porch ceiling like a giant lumpy slug.

Over the course of the summer and fall I tinkered with a pedal-powered threshing contraption, consisting of a horizontal shaft oriented concentrically inside a 5-gallon bucket, with various choppers and flails on the shaft, vaguely inspired by this farmhack video. While we demonstrated the possibility of pedal threshing, in these socially-distant times I soon resorted to a fractional-horsepower 1800rpm induction motor borrowed from a wood lathe. The thresher did function ok, separating the grain with good yield, but it was slow, cloggy, and not entirely satisfactory overall. I was keen to have a continuous, flow-through process rather than batch mode, but with the horizontal shaft there was little (besides the pitch angle of the internal wooden beaters and the draft angle of the molded bucket) to progress the grain and chaff through and out. I think if I were to incline the whole flow arrangement at 30-45 degrees from the horizontal it would feed better, perhaps at some cost in grain yield. The fundamental issue seems to be that I am relying on a statistical process of chaotic whirling around as opposed to a systematic scrubbing or shredding action to reliably separate the grain from the heads. I’ve since done some online research into what the innards of an actual threshing unit look like, and the rotating part is surprisingly crude – variations on a theme in a rotating drum or cylinder with metal pegs or bolt heads sticking out. The subtlety seems to be in the ‘concave’, a slatted metal screen that envelops the cylinder and disposes the stems and heads against the cylinder while allowing the threshed grain to escape through the screen as it is threshed. The flow is sheetwise circumferential around the drum for a fraction of the circumference; there also seems to be subtlety in the airflow and various recirculation mechanisms to give partially threshed material a second pass through the threshing mechanism. For my purposes, it would seem that axial flow would be easier to tune in a hack-y development mode. Anyway, here are views of the inlet and outlet ends of the bucket mechanism I used:

As with the beans, I winnowed the rye using a window box fan and screened the remainder to get clean grain. All in all I extracted about 8 pounds of rye grain from what appears on google maps to have been around .05 acre, with perhaps another 2 pounds in a contractor bag of unthreshed grain that I saved for future experiments. This amounts to a pretty thin harvest on the order of 200lb/acre; in the plains it appears that 20-40 bushels per acre (1,100-2,200lb/acre) is typical for rye, though it appears to be considered something of a marginal crop there and may not get much attention. I won’t beat myself up too much over this unintentional crop on poor soil, but it would be interesting to see what can be done with reasonable effort. As noted above I planted the field corn patch to rye and clover after the harvest, and the area is now a cheerful low mat of green, so we may get a better experiment next year.

At some point Z got his hands on an ear of dry corn; he was really excited about it so I didn’t take it away from him; for anyone concerned about data integrity, the data points for row 10 should be a touch higher…

New Year’s Day 2021; composting diapers

January 10, 2021

On Friday the 1st the temperature briefly crept above freezing, and I took advantage to compost the diapers that have been accumulating since we shut off the irrigation system in the fall. Somehow it often seems convenient to do this process on holidays; I wrote about it last summer on July 4. In winter this involves stretching out about 200′ of hose from the utility sink in the blue room, and then quickly draining it afterwards before it gets too cold. Anyway, here’s the setup:

The wooden double compost bins were inspired by Holly’s much more elegant system in Somerville; I made these from untreated pine boards Dave had sawed in Five Islands. The near one has two 4′ boxes and is our general household and garden compost; the far one is a bit smaller and I use it for the brown diapers and only spread that compost under trees etc.

The process is pretty simple; I throw some dirt or aged compost in the brown trash can, start the hose running in the can, and dump in the liners a few at a time. Then I mix the contents with a pitchfork (we rip each liner lengthwise when we put them in the cat litter buckets, which allows the dessicant to flow out easily when mixed). I then bail the resulting slurry into the compost bin using a drywall bucket, stirring and mixing in layers with typical compost makings, including fallen leaves, garden cleanup rakings, and household scraps. The resulting pile cooks down quickly, fills with legions of vigorous pink worms, and becomes nice compost in just a few weeks of non-freezing weather.

Unfortunately the company that makes the liners (g-diaper brand) seems to have succumbed to the pandemic global logistics chaos, and is no longer distributing in the US. AC laid in a store early last year, and hopefully they last us until Z is out of the diaper stage, but there are other systems that appear similar. 18 months in I still strongly recommend this system for folks with big gardens who would otherwise buy in soil fertility.

On the use of land: A second look at Second Nature

December 31, 2020

At some point in college I came by a copy of Michael Pollan’s first book, Second Nature, about gardens and humans’ relationship to the natural world.  I may have stolen it from my parents’ coffee table, or found it lying around the cozy, fervent MIT cooperative where I lived.   Having been raised by former NOLS instructors on tofu, Thoreau, and Edward Abbey, and on the other hand undertaking at the time an intense education in technology, quantitation, and innovation (electronic paper, 3D printing, underwater drones, implanted medical devices…), the book stuck with me (‘planted a seed’, you might say), and played a part in leading me to these apple trees, this blog, and this post.

Briefly, ‘Second Nature’ presents contemporary environmental thinking about land as a sort of absolutist madonna/whore dichotomy between a few remaining preserved gems of ‘pure’ wilderness and the surrounding matrix of ordinary, ‘degraded’ territory, and Pollan pronounces this absolutist distinction barren – both literally and conceptually.  As an alternative he sets forth the garden as a more fruitful metaphor, both for feeding ourselves and for thinking about interactions between humans and the natural world.  Re-reading after over 20 (!) years, the book is thoughtful, engaging, and still has a good argument to make, one that resonates with my life.

Certainly Wilderness was a guiding star of my youth.  Though my parents were raised in or near cities on both coasts, they met high in the Rockies as mountaineering instructors, and mixed in among the ordinary homesteading tools there were strange artifacts about – wood-handled ice axes, oval carabiners, and hanks of rattle-stiff old goldline. Practically before we could walk, my sister and I had full-sized Kelty framepacks waiting for us, and I remember the pride of finally being (marginally) big enough to carry mine.  Many summers we road-tripped to Wyoming to hike high into the mountains, disappearing across the continental divide where sometimes we’d go a week without seeing another party.

And since my parents ‘settled down’ pretty far off the beaten path, my sister and I grew up two miles from the nearest other kids, as part of the broader back-to-the-land movement which was in conscious opposition to the industrial practices of modern life.  Growing up this way I came to see wilderness as Real, bracing and constant against the artificiality of television, plastic toys, and social cliques.  The mountains we trekked through offered arresting beauty in reward for skill and hard work.  The rock is enduring, the weather uncaring, the alpine trees strong and patient. Wilderness offers a tough but objective test – you either keep your gear dry or you don’t, you make it over the pass or you don’t, and the consequences flow directly from the nature of unvarnished reality. In wilderness it’s clear that the universe doesn’t care about you, but it’s fair and its rules are legible – in that way it’s far superior to junior high.

But, you can’t cultivate a rock.  You can’t eat a view.  As a species we are 7 billion people, ten thousand years down a one-way experiment in intensive food-making, culture-building, and technology-refining, and we’ve been pretty darned sophisticated at it for thousands of years.  For who we are, wilderness is an education, perhaps a vacation, but not a career – while it’s certainly a nice place to visit, we just can’t live there anymore.

Where we live is the industrial economy, and how we live there is mechanized agriculture and massive flows of energy.  The surface experience of modern life in the developed world often obscures this – our skills are transferrable, our communities virtual, our finances digital.  But this is, if not an illusion, an epiphenomenon of the stability, specialization, and efficiency of the underlying physical systems.  Until we upload our consciousness into silicon (as the Singularity squad devoutly wishes), we remain stubbornly physical creatures – to see this clearly look no further than last spring’s run on toilet paper.

The toilet paper thing is a sort of nervous joke, but I mean this in a broad and serious way. We don’t actually have a post-industrial society; we just got so efficient at manufacturing buildings and cars and appliances and electronics that as a society we have enough bandwidth for many of us to toodle around with apps and stuff. Nor in physical terms do we actually have a post-agricultural society – we just got so efficient at agriculture (efficient in economic terms, by using a ton of fossil energy) that we had enough extra wealth/calories to build an industrial society.  The foundation of the information age is hyper-efficient manufacturing, and the foundation of industry is hyper-efficient agriculture, and the foundation of all of it is cheap energy. And the fact that the environmental impact of our lives is largely hidden by offshore manufacturing and high-voltage transmission lines does not make it go away.

Grappling in a real and quantitative way with human environmental impact seems to be what Second Nature is missing. Published two years before Pollan’s book, Bill McKibben’s The End of Nature introduced the US mainstream to concrete and present reality of global warming.  But Pollan doesn’t engage materially with climate change, or really with other large-scale environmental problems. Perhaps this is because he leans so heavily on the crisp dichotomy between wild and impacted land, which was at the very moment of his writing being ruptured by the all-permeating reach of global greenhouse gas emissions.

Pollan was right that wilderness is not a solution for sustaining 7 billion people, and that necessarily the way forward is to thoughtfully cultivate our world (enough of it to live on).  But his book has precious little to say about actually producing sustenance. After a promising beginning among the truck farms of Long Island, the book takes long excursions into the social class implications of rose varieties, the moralistic overtones of compost, and the excesses of seed catalogues, and in the end seems to be more about aesthetics than substance, more about landscaping than actually producing food, fuel, or fiber.  His primary concern seems to be how a well-read suburbanite can display his good taste.

This disappoints me because I believe that the actual physical substance of how we live matters.  To be sure, what we feel and proclaim matter also – aesthetics, symbols, and statements move minds, but minds are also subject to myopia, hypocrisy and wishful thinking.  Rock-bottom physical reality matters at least as much, because all the while as we think and symbolize and post and upvote, inexorably we eat, we heat, we travel (or used to), we buy, and we build, and the effects are real, quantitative, physical. Our microprocessors require electricity, our fingers quit typing much below room temperature, and our lofty professional and aesthetic goals are stubbornly dependent on a pound dryweight of bread, butter, and beans, daily with scant interruption.  We remain tied, physically and therefore ethically, to the land.

Where then should we live, and how should we live there?  Where? There’s no point getting prescriptive about it; we are 7.6 billion now, we take up a lot of space already, and this Covid time is no season to encourage folks moving around.  We should live in our communities.  Urbanites have their own clear paths to low-impact living: density, bicycles, and a thoughtful diet go a long way. For those of us who live in the countryside, the risks and possibilities are broader.

I live in Maine.  Because our state has the lowest population density east of the Mississippi, many of us live on sizeable chunks of land.  While most people in the developed world externalize the environmental impact of their lives, still land and sunlight are the ultimate sources of our sustenance, and the impact does not go away just because we can’t see it.  So for those of us fortunate enough to own acreage, it’s worth thinking about how our land could sustainably produce some of the basic stuff of human life.

I have written much here of my frustration with the consumer model of citizenship. Not that I want to live as a survivalist, guarding a field of turnips with an assault rifle, but nor am I satisfied to be merely a specialized cog in the global industrial machine. Because my life impacts the planet, because land and nature are the ultimate source of our sustenance, and because I have land, I am interested in stewardship.  Because the path humanity is on is not sustainable, I am interested in experimenting and modeling other paths – ways to be productive, physically, of vital goods in a sustainable way and at a meaningful scale.

I say ‘experimenting’ because generally this sort of project won’t make a whole lot of conventional financial sense; it’s more like a hobby with a larger purpose. Why? Food is cheap, real estate is expensive, and the cash economy is lucrative. When a small buildable lot of an acre or so sells for $50-$100k,  basically nothing (except cannabis) can be done agriculturally to match the economics of development.  Still there is a sadness in old farms going to forest or to subdivisions. To be sure, when the railroads spread across the nation, it made economic sense to move production of grain and beans from rocky New England farms to Ohio, Illinois, and Kansas, but nothing came to replace the vitality that went out of the places then. But should the gods of the market dictate next that the staff of life should move on further, to be produced entirely in Brazil or Mongolia, will we then clothe Iowa in condos, and keenly await the grain ships as the Romans did?

In this modern first-world life, our food, shelter, warmth, transportation, and electricity all come from the global economy, which is 80% fossil-powered.  Our land lies fallow as we heat our homes with petroleum, eat supermarket food grown with Haber-process nitrogen, and build with lumber trucked in from Canada or beyond. Those of us with the freedom to choose should contemplate instead how we might do better by thoughtful use of our land. What practices can I take up, such that if if my neighbors and my bioregion followed suit, the result would be a stronger community, a more vital countryside, and a gentler impact on the broader world? What sustenance and beauty could we bring forth, and what might that do for our health, our communities, and our planet?  

One interesting consequence of the intersection of ubiquitous internet search and ubiquitous aerial imagery is that it isn’t hard to go looking and find places that would previously have remained literary abstractions.  So without much effort I was able to find the western Connecticut property that was the centerpiece of Pollan’s book.  And in 2021 only the barest hints of the hardscrabble dairy farm he describes are visible.  From the air and the street we have what appears to be a typical high-end exurban home in the woods, with more-tasteful-than-average landscaping.  The only hint of anything out of the ordinary is a few raised beds, heavily shaded by large trees. Like so many former New England growers, Pollan has picked up and moved west, and the forest has largely reclaimed his efforts. 

Reflections on a summer of serious gardening

November 15, 2020

Ever since landing in Arizona I’ve gardened where I could, but this summer the stars aligned, and I applied myself to it more seriously. While I’ve complained about the limitations of backyard gardening as a response to hard times, the underlying instinct is surely sound, and obviously I feel it myself. In redoubling my efforts, my goals were to:

Broadly speaking it was a great year. Below are some notes and thoughts on what I learned, organized by vegetable crop; I hope to do a post on my experimentation with staples soon.

As usual we grew quite a lot of potatoes. It’s not for any logical reason I can tell; new potatoes in summer are delicious, but we grow more than that – I think it’s for the joy and symbolism of it. The plants are so happy and vibrant-looking, and digging them up is like discovering Christmas presents. I started in late March or early April with a box of wizened, shrunken red potatoes that got away from us and started sprouting in the basement. As an experiment I dug a trough in some of the newly tilled ground, stuck in the sprouted potatoes, and tented over them with used window sashes. They got off to a slow start, as it was occasionally still snowing that eraly in the season, but even the ones that were outside the glass tent re-sprouted eventually after the first tips got blasted by frost. The bulk of our crop we planted back in the main garden using seed potatoes from the garden center or fedco. They don’t need much attention besides hilling and diligently picking the beetles (or an application or two of spinosad, which I use on occasion). The kids love digging them; Z got right into it and put them in the bucket while I turned the soil with a fork.

Strawberries I think we’re starting to get the hang of; we grow them because they are delicious, luxurious, and not actually too much work. I used to think of them as finicky but at least in our soil they go quite rampant, taking over the aisles and nearby beds and continuing to grow late into the fall when hard freezes have flattened lesser plants. This year in the early spring J&K transplanted some runners into new beds near the greenhouse, including a shovelful of soil with the plants (‘strawberry sod’?) and they took off and produced a decent crop. Toward the end of the season the berries get small, and it got to be a bit of a chore to pick and freeze them, which is good I think in that it reminds us that we don’t actually want everbearing strawberries, and For Every Thing There Is a Season. They need to be weeded diligently, but the biggest problem is waxwings pecking the ripe fruit. In the past we have used floating netting, but sometimes the birds get under it and thrash themselves to death, which is less than pleasant. This year I criscrossed flash tape above the beds instead, and it seemed to be mostly effective and less work.

Fresh greens are a big part of why we garden. This year that started early with lettuce, kale, and spinach from the greenhouse, and we (Kelsey mostly) did pretty well at succession plantings (out in the beds, not in the greenhouse) to keep us in salad fixings throughout the summer. For me the big discovery of the season was broccoli raab. I grabbed a packet at O’Donals or somewhere early in the year, and was amazed at how much faster it grew compared to other greens, how free it was from worms and bugs, and how it would hang in for a good while before flowering and going to seed. The rest of the crew here is less excited about the bitter greens flavor than I am, but I will continue to grow it for its vigor and sheer enthusiasm.

Continuing on the brassica theme, I had resolved to grow a lot of broccoli this year, since it’s nice fresh and we also use a lot of it (mostly bags of frozen from TJs) – I hoped to freeze a bunch for the winter. We started some in the greenhouse and transplanted out a dozen or so, and they did OK, with the majority producing a respectable medium-sized head followed by side shoots the rest of the summer. I think I planted them too close together, and they would have benefitted from more compost. I ended up freezing a couple gallon bags of florets, but ended up feeling that I could have done better. We had some extra healthy-looking seedlings in the greenhouse that I couldn’t bear to ditch, and we were already fully planted out, so I put them in large (5 gallon?) plastic pots we had lying around, mixing in compost at as much as 50%. These did OK but probably would have done far better had I planted one or two to a pot instead of 5 or so. The meta-lesson is not to be sentimental about seedlings – as it is written, Many are Called, but Few are Chosen.

I also planted some cauliflower that acted strange; it eventually grew heads but they were heavily interspersed with green leaves, such that it was kind of a dissection project to eat it. I should probably think ahead and order from Johnny’s or Fedco rather than trusting a garden center seed rack next year. We grew kale as usual, and it did well as usual; Kelsey also grew a big bed of collards of which they may have eaten a few meals, and Holly in Somerville grew a kohlrabi the size of a football. As the season winds down and colder weather sets in the brassicas grow on me; even after 17F there are still some broccoli florets hanging in there, and I wish I had some brussels sprouts. I’ve started my winter salad regime of shredded red cabbage, grated carrot, and kitchen-window alfalfa sprouts; maybe next year I’ll plant some cabbages. The biggest problem with brassicas is the little green worms; one theory to try for next year is to plant them all in a row to facilitate a more disciplined application of Bt.

One of the meta-lessons of garden planning and meal psychology is that early-season stuff like kale and chard quickly lose their appeal when the midsummer vegetables come in. A frank acceptance of this might have us harvest and freeze these crops en masse as the zucchinis etc. start to come in, and reuse the space for a succession crop.

The value of succession plantings become clear this time of year, with the sturdy holdouts offering cheer as everything else dies back. Carrots and spinach seem to be the most robust, surviving a hard freeze that withered most of the lettuce and chard. We did a pretty good job with successive plantings of both, and are harvesting them still. We tried likewise with beets as well but could have done better; we discovered along the way that goldfinches peck the leaves to the point of destruction.

Alongside the carrots and spinach the leeks are also green and hearty, and we’re pulling them as needed. They grow easily once started, and grocery-store leeks are $2.50 each, so despite their modest aspect, they definitely counts in the luxury category. Regardless of means, I would have a hard time putting $15 of anything in a humble pot of soup, so growing them in profusion feels like a particularly snug form of wealth. The only change for next year is we should have planted them deeper to make the white part longer, though Holly says we should just roast the green parts with salt and oil – I tried it and they were OK; I found myself keeping a container of them in the fridge and chopping them into e.g. fried rice to good effect. In other allium news, Kelsey grew the usual bed of garlic and started some onions from seed; they seemed to falter (perhaps from the drought) but eventually caught on. I also planted a bag of onion sets that did a bit better; we always use up however many onions we grow, so if we come up with good technique we could scale it up.

I enlarged the garden early in the season, and upgraded the fence as time went on this summer. The construction now consists of 5/4×6 PT decking set edgewise and buried 1-2″ below grade, with economy cattle panels from TSC set above it, screwed to 4×4 PT posts on 16′ spacing. This construction replaces an amalgam of slabwood, chicken wire, plastic netting, and untreated tree trunks we originally put in, which had rusted and rotted into the ground over the last 10 years. The fence is a bit extravagant, but we spend a lot of time up there and it’s a pleasure to use. I can run the BMX-bike wheelhoe right up against the boards on the inside. That wheelhoe has been a revelation; with it I was able to keep the entire ~1/6 acre from growing up in weeds with 10 minutes here and there. For finer work I used a regular straight hoe and a small Japanese hand-weeder that my mom gave me; Kelsey uses a small Korean hand plow.

The edgewise decking at the base of the fence similarly resists the string trimmer on the outside, and the cattle panel is good for trellising crops, allowing us to use the soil right up to the edge of the garden. In exposed places I’ve strung three strands of 17ga steel fence wire above the cattle panels to discourage deer, and I lived in fear that we would get coons in the corn and I’d need to add an electric element, but thankfully they never found us.

As the weather warmed and the crops started to come in I had less time to put the finishing touches on the fence, and as a result my crop of butternut squash was badly damaged by woodchucks; as is I got maybe half a bushel and we have a bunch still in the freezer from past years so we’ll manage fine for pies. We also grew the usual zucchini and summer squash, and as usual it produced well before getting nasty with mildew and beetles. The revelation this year in cucurbits came from a garden-center packet of light-green pattypan squash; I planted one hill of these and it took off like a rocket. It spread out into a jungle maybe 12′ in diameter that produced an absurd amount of squash, and unlike the single-threaded zucchinis it had a persistent branching habit that survived several attempts to cut it back out of the aisles. Also unlike zucchini it seemed unfazed by the bugs and mold, and produced continually until the weather got cold. With the warm dry weather we also managed to grow some quality cantaloupes and a few watermelons, trellised along the garden fence.

Other crops reliably did their thing – tomatoes, green beans, sugarsnap peas, etc. Southern Maine was dry this summer, and we irrigated a fair amount. We have a pretty good system now, using the sort of oscillating lawn sprinklers that have a bow-shaped metal tube with a series of jets pressed into it. The sprinkler is screwed to a short piece of decking, with a rectangular wooden tube about a foot long screwed to the underside of the decking. The tube slots down over a wooden post driven into the soil, setting it at about head-height, above the tomatoes and peas. The garden is long and narrow, so one sprinkler can manage the entire width of the garden, and six or seven posts allow us to move the sprinkler to successively water the entire area. Kelsey also does a fair amount of hand-watering, which keeps the weeds down in the aisles, and we have some drip tube here and there.

I think that about covers my ‘lessons learned’ from a summer of serious gardening – we’ll see what next season brings…

Independence Day 2020, composting diapers

July 4, 2020

We had a quiet but productive Fourth today, including the ceremonial digging of the first new potatoes, which we ate for dinner together with the first of the broccoli and some mini bok choy.  The corn is far past knee-high, the strawberries are winding down, and the zucchini are coming.

One of the things that has contributed to the good garden this year is a much greater quantity of compost, which we have on account of the diapers I’ve been composting since last summer.  We’ve been using the ‘g diaper’ brand, which consists of a cloth shell, a waterproof rubber liner, and a disposable/flushable/compostable insert with the magic dessicant in it.  Thanks to the Georgetown Mall I have some kitty litter buckets with close-fitting lids, and we keep separate ones for yellow vs. brown, ripping the paper skin to free the dessicant. ( We do use one disposable diaper per night, as the compostable ones definitely don’t seal as well or hold as much.  These are theoretically biodegradable, but I’m skeptical and haven’t tried it out.)

Once a couple buckets full accumulate, I put them in a ~20 gallon rubbermaid trash can, add a couple scoops of dirt or compost, and fill the can with water from a hose to completely hydrate the dessicant.  I stir the resulting mess with a manure fork, let it sit for a few minutes, then bail it into the compost bin, mixing with wood chips, weeds, grass, leaves, planer shavings, etc. – whatever we have around.

The yellow ones I compost directly into our regular compost bin, a dual 4’x4′ wooden box that I built inspired by Holly’s very trim setup in Somerville.  The brown ones have their own smaller dual wooden bin, where I will give it plenty of time and then spread under some trees or something.

Based on my experience I would highly recommend this approach to diapers.  The diapers themselves don’t actually add that much volume to the compost, but they do add nitrogen, and they inspire me to collect a lot more organic matter to put into the process.  The bins are full of worms and other wriggly life, the piles compost quickly, and the resulting compost is dark brown, smells fresh, and the plants seem to love it.  There is no sign of the paper or the dessicant particles in the finished compost.  Because the vegetable matter feedstock we use varies widely in size, I screen the finished compost through half-inch hardware cloth, which separates out the avocado pits, corn cobs, stubborn vegetable stalks, etc. to go back in the bin.  I then put the screened compost up in dogfood bags until it’s needed.