Archive for May, 2008

Why we should stop eating (industrial) meat

May 30, 2008

Followers of agriculture and energy issues have noticed these subjects getting a lot of press lately, what with the combined effects of climate change, biofuel production, developing world dietary shifts, and petroleum scarcity driving prices significantly higher. Especially country kids like me, the natural instinct is to plant a big garden and exhort others to do the same, and this is indeed what I have done, as reported previously in this very blog. Prominent crunchy types including Michael Pollan and Barbara Kingsolver have similarly advocated gardening as a solution to the food crisis, and people are increasingly paying attention – Fedco Seeds sent a flyer with my shipment this year remarking that they had never had such a good season.

But renewable energy engineering folks also have a habit of running back-of-the-envelope calculations to determine whether a particular solution has any hope of succeeding. I did some simple estimates some time ago that showed the difficulty of making a significant impact with dooryard gardens. For example, the classic garden vegetable is the tomato. How many people could I feed if I grew nothing but tomatoes? Iowa (which is a pretty good place to grow things) says that typical yields are around 14,000 lb per acre, though much higher yields are possible. Florida says that a 148g tomato provides 25 calories, or about 77 calories per pound. So an acre of tomatoes might produce about 1.08 million calories, which seems like a lot. But a person eating a 2000 calorie per day diet will eat 731,000 calories per year. That means an acre of tomatoes could only feed about 1.5 people. I’m not sure how familiar most readers are with the size of an acre, but it’s pretty big – about the size of a football field. A decent suburban lot is maybe a quarter of an acre. My front yard garden is around 1000 square feet, about a fortieth of an acre.


Pedal-Power irrigation pump

May 27, 2008

Right now we are watering the new-planted trees in the orchard by hand with buckets, but discovering that my grandparents old man-made “deer pond” is just a few inches below the top of the orchard got me thinking about how we might irrigate the orchard, if it ever came to that with climate change and all.  The modern way would be to buy a nice little Honda 1″4 stroke pump to push the water, but there’s no romance or challenge in that.   And if you do the math, it turns out that it doesn’t take much power to move a lot of water if the head (vertical lift) is modest and the system is efficient.   With SI units you can pretty much do it in your head:

P = Mdot * g * h / eta

P is shaft power, Mdot is the mass flow rate (kilos per second), g is gravitation (very nearly 10 kg*m/s^2),  h is the total head (meters) , and eta is mechanical-to-fluid efficiency.  So if you had a 3 meter lift and 50% efficiency, you would get over 1.5 liters per second from a 100W source.  That started me thinking about a pedal-power irrigation pump.  The idea would be to pedal for a few minutes and fill a cistern or reservoir on the ledgy hill above the orchard, whereupon a drip system of some kind would slowly feed that water out around the bases of the trees.  I started by thinking about a piston type pump, because the well pump we have seems remarkably powerful given that it is operated by one hand and looks to be about a hundred years old, with leather valves and whatnot.  It can fill a bucket in just a few seconds of vigorous pumping (~1 liter per second?), and the total head must be between 2 and 3 meters, so it must be capable of around 100W with reasonable efficiency.  With pedal power that amount of effort can be sustained for long periods, and higher rates are possible for a limited time.

In poking around a bit on the internet several groups have built pedal pumps, but nothing that strikes me as really compelling.  Low head pumping is often done with an axial flow pump (basically like a boat propeller in a circular housing), but that requires a setup with a slanted shaft to submerge the prop in the water; sounds like a bit of an annoyance for rigging up pedal power.  So I’ve come around again to the idea of a piston pump.  For efficiency the important things will be to keep the ports and ducts large (to avoid pressure drops) and make efficient check valves (to avoid backflow and pressure drops there).

The idea I’m currently excited about goes as follows.  First, the drive would borrow heavily from the cider mill.  I figure to design for about 1Hz operation; that way it goes at about pedaling speed and you can gear it up or down a bit by fiddling with the sprockets if you get the loading wrong.  Front forks of bike bolt to assembly; a loop of chain goes forward to the main shaft of the pump, which has a thread-on 5-8 speed freewheel clamped to a 5/8″ shaft as with the cider mill.  I’d put another, large sprocket on the main shaft and couple it to a much smaller sprocket on a jackshaft, which would carry another cast iron flywheel to smooth out the rotation and for style points.  A simple machined crank cantilevered off the opposite end of the mainshaft would have threaded holes for a shoulder bolt in several radial positions, to allow the stroke to be adjusted.  A crank arm with spherical rod end bushings would connect the crank to the piston rod, which would be supported in the pump assembly by brass bushings reamed to a close clearance to minimize leakage.  O-rings could be fit but I’m worried about the friction that would ensue.

The pump assembly itself would be double acting to minimize cyclical forces, and it would consist of a 3 or 4″ PVC cylinder (gotta figure how to ream out the inside to eliminate the minor cellulite-like texture that seems to result from the extrusion process).  Each end of the cylinder would have a double side entry reduction fitting (topologically like a T shirt, but with a big neck hole) for inlet and outlet ports, and the axial port would be reduced down to the point where the cylinder guide bushings could be directly attached.  The piston would be a disk of hard plastic, bolted to a shaft collar on the piston rod, with a groove turned in it to accept a teflon strip edgewise to form a piston ring.  I haven’t got the details of the check valves figured out but I think they involve conical reduction fittings and rubber “superballs” to form the one-way seal.

The whole thing would be mounted to a chassis of scrap PT timbers, and it would sit up in the woods where it would command a view of both of the orchard and the pond.  I can picture it in my mind’s eye; now if only I had the time to build it…

Cold spring, progress on NH garden

May 24, 2008

After being away for a few weeks it’s good to be home and get back to the NH vegetable garden.  I planted the cool season stuff before we left and much of it is just barely above ground – the weather has been cold and things are only now getting started.  The peas are six inches tall but the potatoes are only about an inch tall and the greens, beets, and carrots are not even that big.  Things look warmer going forward and the soil has had a chance to digest the two trailerloads of horse manure, so I put in most of the rest of the garden.  I planted bush beans and edamame soybeans, two varieties of corn, cucumbers, zukes, yellow and pattypan squash, pumpkins, butternut squash, more lettuce, greens, and broccoli, bok choi, basil, spinach, and parsnips.  Tomorrow I’ll retrieve the tomatoes from our friends who have been watching them and plunk them in as well.  Then all that will be left is the peppers and eggplants, which will wait until it gets really warm.

Despite the cold the land is greening up wonderfully; it’s that beautiful time of year when all the fresh leaves are impossibly vibrant and fresh looking – it always makes me wish I were some kind of ruminant, so I could eat it instead of just looking at it.  As it is I’ll just have to be satisfied with eating out of the garden, when it finally starts to produce.

Orchard weekend pics

May 23, 2008

Thanks to Brandon for linking some pictures in the previous post.  Here are some more photos from the orchard weekend and since:

first blossom in the orchard (we won’t let them fruit for a couple years yet)

And a peach blossom

A row of trees

more trees

Transporting the replacement outhouse for the upper cabin

And lowering it into position

More fencing; odds and ends make a long day

May 19, 2008

AC was on call at Maine Med last weekend, so I went down to Five Islands for some more ag-themed fun.  My grandfather (who is near 90) still keeps an impressive vegetable garden, but of late he has required help putting up the wire-mesh fence around it every spring.  Fresh from the experience with the orchard fence, we decided it would be more attractive and less work in the end to put up a permanent electric fence around his garden and apple trees.  His apple trees have suffered significant deer and moose damage over the years since their last dog passed on.  The model was the same as the orchard – 4×4 corner posts attached to trees, one free-standing 6×6 corner post with a diagonal earth anchor, 6×6 gate posts with a timber across the top, double swinging wooden gates, tensioned 14ga galvanized wire.  My aunt and ~uncle dug two of the holes, the bobcat dug the third (rocky ground) and we put the whole business together in a long Saturday.  This included trimming some branches from the corner trees and dropping a malformed 12″ oak that leaned over the apple trees and grape arbor.  We finished the gate and electrified the fence around dinner time.  The circumference was a bit less than the big orchard, around 0.1mi, so it probably encloses about a third of an acre.

Sunday was to be a relatively laid back day of puttering with no major undertakings.  I hitched up the cordwood hauler and moved about half a load that had been accumulating near the orchard, then Emily and I removed the stuff from the oak we took down from inside of the new garden fence, passing triumphantly through the new gate.  While I had the hauler hooked up we went back into the woods and collected a full load of maple and oak from the clearing along the stone wall where the maples will eventually go.  The wood had been sitting for more than a year in one case and needed to be collected before it softened up.  Unsplit  maple dries remarkably well in the open, oak less so, and birch not at all.  The nut on the pin holding the trailer to the tractor vibrated off during the return trip, necessitating a trip to the garage to get a hi-lift jack to reconnect it.  We added that wood to the pile, making the total haul for the day near to 2 cords.  The price of green fitted wood in Lebanon has increased from $140 last year to $190 this year, presumably because of increased demand with the high price of heating oil.  Meanwhile there’s a ridiculous excess in Five Islands with all the orchard preparation; but it’s hardly worth the gas and wear and tear to trailer it up there – if I had more time I’d fit and dry the wood in Five Islands, sell it, and buy green wood in NH, but other activities get priority, and so the cordwood accumulates.  If only my buff sister and her hulking husband would hurry up and move back to the farm they could do a good side business in firewood.

Trading the cord hauler for the wagon, I commenced to fill 5 gallon drywall buckets at the newly refurbished well pump, and hauled them to the orchard, watering the trees and leaving a set of full buckets for my mom to water with if the weather necessitates.  My dad and I set up a transit to shoot a grade between the pond and the orchard, finding to our annoyance that the highest trees are a mere 9′ above the pond, precluding siphon-based irrigation.  Gotta think on a bicycle-powered pump for orchard irrigation.

I then mixed up some white interior latex paint with drywall mud, and Emily painted trunks (to ward off borers) while Dave and I hung the door on the replacement outhouse for the upper cabin.  I noticed a handful of missing insulators on the orchard fence, so I got a 6′ stepladder and put them on, then I patrolled the fence line with a shovel, pulling grass, adding to the stone embankment under the north side of the fence, and filling in a few gaps, as well as editing the moats around the trees to hold more water.  By that time the day was well on, and I was thoroughly whupped.  With the exception of the loads of cordwood no one thing I did amounted to much, but taken as a whole it somehow turned into a hard but quite enjoyable day of work.

It’s an orchard!

May 18, 2008

Last weekend the orchard was planted, thanks to the concerted efforts of my family and generous help from Brandon, Sharon, Keith, Beth, Holly, Becky, and little Ultraviolet. The weather was sunny and cool, and the trees were just starting to show their first green. First up we cut and placed intermediate posts cut from used decking at 10′ intervals to support the wires between the corner posts and hold up the backup deer netting on the inside. We mounted insulators on the outside of these posts, and stapled the netting to the inside. Brandon and Sharon built a pair of swinging gates to complete the closure, and my dad used the little bobcat excavator to grub roots from the perimeter of the orchard and adjust the position of the drainage ditch on the north side. Holly and Alexis made a very smart looking small dry stone bridge over a piece of scrap 8″ culvert to pass the ditch under the fence in the northeast corner. I also reassembled the pump box in the wellhouse, incorporating a new leather that my grandfather bought at the hardware store.

On Sunday we started moving trees from the nursery bed. With a couple shovels we cut around the roots of the trees and levered them out of the ground. The sandy soil partially fell away from the root ball, and we put each one in a 5 gallon bucket for transport up to the orchard. Using my grandfather’s ancient Sears lawn tractor with a small wagon we took the trees to the orchard, along with a 5 gallon pail of water pumped from the well for each tree. My mom turned in the piles of compost and seaweed that we made over the tree spots in the fall, and we dug holes and carefully planted the trees, watering them in thoroughly. In addition to 16 apple trees we also planted 5 peach trees in between the apples; these will grow up and fruit as the apples are gaining size, and probably die off about the time the apples start crowding them – at least this is the the plan.

It’s great to have the orchard finally being an orchard, as Brandon noted, and to have a fantastic group of friends join us to help and celebrate its beginning. By my very rough math, when in full production a half acre of apple trees should be able to produce enough food to feed about half of a person – we’re beginning to do our part to ease the global food crisis. There are five more apple trees and two cherry trees still in the nursery ready to be transplanted when the western side of the orchard is ready, and about 20 maples still waiting to be transplanted along the stone wall down to the shore. Things are coming together nicely.

Also of note, the reinvigorated well pump works very nicely, filling a five gallon pail in just a few seconds of modest effort from the ~14′ deep well. The water is cool and sweet, just as I remember it when I was a kid. We also set the new outhouse over its hole up behind the upper cabin by the orchard. Perhaps the most memorable part of the weekend was when the excavator picked up the outhouse through the open front door and carried it up to place it gently over its hole. It still needs to be screwed down to the base and have its door hung, but it is functional in its current state – nice to have it there.

Thanks again to everyone who helped out – in a few years there should be plenty of cider and apples for all.

The best season…

May 5, 2008

Or maybe the second best, after fall.  We were down in Five Islands last weekend and things are greening up very nicely.  The daffodils are in full bloom, the forsythia is rioting, and the grass has that you-could-just-eat-it look of freshness that always makes me wish I were a ruminant this time of year.  Of course it rained most of the time we were there, so our activities were a bit constrained.  My dad just bought a forestry winch for the Kubota tractor, a cool Norwegian device that makes it easy to twitch logs out of the woods without damaging the surrounding trees.  It’s the next best thing to a team of horses, and it’s just the ticket for managing and improving the weedy second-growth woodlands on the island.  I cut the PTO driveline down to length and fitted the safety guards, and we attempted to repair a damaged adjustable class 1 toplink but it was beyond repair so we cut it down and welded it fixed at 16″, the right length for the winch.  We also changed the oil and filters on the little excavator, and did some other minor maintenance.  I ripped some more used lumber down to make intermediate posts for the electric fence, and planned for the gate that we will be building.  I also built a new pump box for the wellhouse.  The old one was made of pine boards and it had rotted away from the damp over the last couple of decades.  My mom and I built a new one out of scraps of AZEK, which is a soul-less plastic substitute for wood trim, but perfectly suited for this application as it will never rot.  The old hand pump that goes in the wellhouse was also tired out; the leather had completely rotted away from disuse, but my grandfather has replaced it many times before and hopefully he will get a chance to work it up again soon.

We also made a door for the new outhouse for the upper cabin.  I am quite proud of this outhouse as it has been constructed entirely of scrap, used, and reclaimed materials.  The entire undercarriage is made of treated lumber, and it’s diagonally planked with used 1″ boards which makes it almost as sturdy as if it were brick.  The flashing and shingles were scrap/extras, it has a genuine toilet seat (reclaimed from a construction project), and even a piece of scrap stainless steel sheet metal to line the chute.  To top it all off, it has a genuine plywood country-kitsch TP holder that came from the help-yourself building at the town transfer station.

Finally, we fixed the electric fence, which was damaged by some creature (presumably it hit the wires at a run when it wasn’t expecting them there).  The rye and vetch inside have not been browsed, but one of the wires was shorted to the ground and the battery was dead, so we fixed up the wire and recharged the battery on the solar charger.  There are two big rolls of 7′ deer netting on order, and they will be put up around the inside of the fence to further discourage incursions.  My mom heeled in the new trees in the nursery, and everything is ready for the big transplanting – fingers crossed for good weather!