The full name of the document is “Specialty Crops for Pacific Island Agroforestry: Farm and Forestry Production and Marketing Profile for Tea (Camellia sinensis)”. It’s online at agroforestry.net (or directly to the PDF).
I contributed a bit to the document, with some reviewing, an illustration of using ginger as a mulch, and some notes on economics. I’m quite happy with the result, which in 32 pages manages to describe a great deal of what someone needs to know to grow tea in Hawai’i, and process and market it. There’s also some eye-opening statistics about tea in the rest of the world, where the cost of production can be 50x less.
A lot of this information is hard to come by unless you have one of the tea textbooks (the spotty Hajra book from India, or the wildly expensive Willson book from the UK), so it’s great that much of the important knowledge is now online for free.
Meanwhile, our tea continues to grow with astonishingly well. I am baffled by the textbooks which say tea should be “pruned back once every 3–4 years to a height that is comfortable for plucking.” Our tea only takes a few months to go from flat hedges to a wild, tall, profusion of growth. If this keeps up, it will need serious pruning twice a year just to keep it harvestable. Perhaps more frequent and aggressive plucking would help keep it under control, but there there are many other things on the farm (and building the new house) which distract from harvesting. One thing is for sure: the conditions here are very, very good for tea. The soil (just compost, biochar, & mulching) and wet Hamakua weather seem to be perfect.
Those of you following the biochar-hawaii list know that i’ve stopped using my kiln, and am now focused on making biochar in a pit. This is both for reasons of scalability and wear; my 55-gal steel drum kiln/retort could only make ~23-gal of char, and the surrounding kiln blocks cracked from repeated heating.
Hence, a pit. Mine is lined with blocks for clean char and easy unloading. Continuously fed wood, pyrolysis occurs at the air-starved bottom of the pile, gradually the pit fills up, then i cover and let it cool for a day, before opening and scooping out the finished char:
That first small pit worked well, so i made it bigger and sure enough, it scales well:
Width
Length
Depth
Gallons
Cubic feet
# of blocks
Gallons of Char
24
32
16
53.2
7.11
33
16.5
32
48
16
106.4
14.22
48
34
32
48
24
159.6
21.33
60
68
32
48
24
On second burn:
82
That 82-gallon operation took 2.5 hours to do the burn, then 2.25 hours the next day to unload, crush, sort, sift, and load into buckets. That’s 82/4.75 = 17.25 gallons of char per hour of work. That’s not bad, given that i’m working with some cheap concrete blocks, a piece of old corrugated roofing, and a shovel. With more money and technology, like a continuous pyrolysis machine, you could certainly get vastly more char per hour of labor, but those machines start at $100,000. I’m feeling quite happy about my pit. The Biochar2010 album has all the pictures.
I gave a biochar talk to the Kona Coffee Grower’s Association on June 2. 10 minutes of that talk got uploaded to YouTube. I then addressed the Hawaii Tropical Fruit Growers on July 19, that time with a fancy presentation with charts and pictures. Next will probably be an evening talk in Waimea on August 8, and then a 1-day workshop on making and using biochar here at our farm, date TBA.
Most of what i’ve been up to on the farm recently relates to biochar, but to keep this from becoming an all-biochar blog, here’s a bit about the garden.
I grew a patch of sunflowers this summer, planted mid-April. I needed to use row covers, to protect the seeds and sprouts from birds, until the plants are a few inches tall. It took 3 months for them to mature. At first i noticed that a lot of bees, and even butterflies, were interested in the flowers:
Soon after, i noticed cardinals feasting on the mature seeds, balancing on the tops of the head and pecking the seeds out, and shelling them right on the spot. That indicated they were ready for harvest, so i gathered a few for the chickens, then soon after, Deb harvested them all, dried them in the greenhouse and saved the biggest one for seed.
I recently did a second and third burn in my biochar kiln, tweaking each time. The story is best told in pictures:
Upon detailed inspection, the April test burn actually gave good results. Four white buckets are completely charred material, two orange buckets incomplete, one mixed and one of material from the surrounding fire.
Completely charred wood from retort, and the incompletely charred – only a small amount, and generally from the bottom of the barrel, perhaps due to a lower temperature there.
Preparing for burn #2, using smaller wood and some changes to the kiln.
Added a layer of firebrick at the base. Ideally, it should enclose the whole chamber, but that would take a lot of actual masonry.
More air inlets, allowing air into all four corners.
The ‘chimney’ is formed by the blocks themselves.
Smaller wood scraps for burn #2.
Opening the kiln after burn #2.
As before, the material at the bottom of the barrel (top, when inverted like this) is less charred, but everything above (below) it is completely charred
Much of the sticks that look brownish on the outside are actually completely charred black on the inside
Burn #3
Got the fire real hot this time, you can clearly hear the “whoosh” of the pyrolysis gasses from the barrel joining the fire
Sifting/crushing/sorting the result. Some 1/2″-minus has direct uses. The rest will soak in nutrients to charge it, then goes through the chipper-shredder to make “charged fines” – biochar fertilizer.
It’s been a long time since we’ve blogged about tea. The field has been growing exceedingly well, particular in the wet wet weather which stayed wet until mid-April this year. Tea loves rain! Our February 22 harvest, a full-bodied oolong, was announced on facebook and did well. The May 1 harvest experienced difficult conditions, surprisingly hot and dry, which sun-cooked the leaves even before processing. More recently, we did a harvest on May 21 which was made into two kinds of green tea: classic Chinese green, and my attempt at a Japanese green. The Chinese turned out very good. For the Japanese, we don’t have one of those heated tables that traditional rolling is done on, so i improvised. The result is promising – it does taste like sencha – but probably not yet good enough to sell. You can try some if you come by the farm.
Recent intern Alisha, picking leaves for the May 21 harvest made into green tea.
After the major pruning of 5/25, all the older plants are now hedges
Some young tea plants, freshly planted up the hillside. Recent intern Comus helped with much of the planting.
View of the lower field which is nearly all grown in, and now pruned into hedges
Note the pruning makes a lot of stick-ends, each of which should sprout multiple leaves next time, all at the same height for abundant and easy harvesting
As a followup to my last biochar post, i was sent the following document from Karl Frogner of UBI. Karl asked me to make it available, so i’ve put it here: Biochar Ovens, until UBI has a place for it on their own site.
It describes experiments conducted in Mongolia on making biochar in a steel drum where the combustion occurs in a metal center tube. Innovative and fascinating! I want to try it here on my farm, but i’ll have to somehow locate some heavy large-diameter metal pipe, and be able to make holes in it.
My friends Josiah and Jay down in Puna are producing biochar using a classic pit method, which seems to work well. I may end up making char that way as well, but there is some criticism on the biochar list of open burns, saying that emissions aren’t fully combusted and carbon yield is low, recommending a kiln or even better, a retort (closed “cooking vessel”). So, i looked at plans online and found two approaches, the two-drum and the Twin Oaks, particularly as built by Kelpie in Oregon. The first approach is too small a batch and requires multiple drum sizes, the second requires expensive metalwork including pipes and welding. I came up with a hybrid of the two approaches which should be cheap, simple and high yield.
I did my first trial fire-up yesterday. The trial results are from this picture onwards.
Results were promising, but need tuning. I learned a lot from this trial run. Some indications:
The kiln fire needs to be strong and hot and heat up fast. My kiln burned moderately, for a long time, so it didn’t fully cook the retort.
More air inputs. I was hoping to limit openings to focus the heat inside. I put vents on the left and right and front, but the fire seemed to want more air.
A round barrel in a square box isn’t great geometry for a fire, which tends to burn separately in the four corner “zones”. I could try stacking the blocks in a more circular arrangement, like a hexagon/octagon. If i stay with this arrangement, i’ll need air vents specifically pointing into each corner.
Chimney. I figured a simple rectangular hole at the back should suffice, since it worked for Kelpie. But mine didn’t seem to draw well. Charcoal kilns for a thousand years have had proper chimneys. I’ll probably need one too.
Insulation. I used regular CMUs because they’re cheap and available. No doubt better insulation would result from using firebrick, thereby focusing more heat inside. I could also fill/bury the hollow tile walls, even if they’re dry-stacked.
The half-charred results of this trial aren’t useless; they could still be used for a less-smoky cook fire, or dropped through my shredder to make mulch with a more stable carbon content. However, the goal remains easy, cheap, reliable full pyrolysis. If it doesn’t pan out with this design, i could always switch to a pit, or hybrid brick-lined pit, or other ideas.
I read the Transition Handbook last year. It’s a growing movement, and it’s full of great ideas for making sustainable local communities. There are lots of issues to figure out, about how to interact with local government, and finding the people who have the time and talent for organizing. I’ve spent some months thinking about how my community could use the Transition model, and there’s one other major issue: Geography. Transition works with face-to-face meeting; that’s a fundamental pillar. Not just monthly face-to-face either, but frequent. That means a community that lives close to each other, within a small area.
The area i live in, Ahualoa, is around 3×2 miles, 6 square miles. That might be OK size-wise, but there are drawbacks:
1. A 1000-foot rise from one end to the other makes getting around more energy-intensive.
2. Few roads (no grid or spokes) and no paths, so to avoid trespassing you have to walk/drive a long way, to go a short way as an ‘io flies.
3. Many sparsely-inhabited 20-acre lots means low population density.
4. No central point or public space. 60 years ago, we had several small schools and, i believe, a store. These are long gone. There’s nowhere to meet or barter.
You can see the pattern of big lots with few roads:
Unless we can improve these issues, Ahualoa remains in danger of being a 100% car-dependent ‘bedroom community’ to other places – which is a very bad place to be when only the rich will drive cars.
Meet “Lil’ Buff,” a super-friendly hen amongst our motley crew of 9 remaining gregarious hens.
Lil Buff (Nov. 2007, almost 2 yrs old)
Buff Orpington hen plumage
Lil Buff in a broody mood
Deb and 3 Buff hens
Lil Buff in front of my Red Ti plants
The Buff Orpington is a dual-purpose breed and lays tinted brown eggs. She has golden plumage with lots of fluff around her legs and tail. Lil’ Buff’s calm, curious temperament makes her an ideal mascot during farm tours. She is smaller in size compared to my other Buff hens. Because of her small size, I can carry her around for quite some time. She tolerates lots of human handling. I have two remaining Buff hens left: Lil’ Buff and Big Buff Too. he’s got a distinctive high-pitched chirp unlike any of my hens. Listen to her as she checks out the woodshed in this short video. (The other soft clucking you hear is a Silver Laced Wyandotte, no longer in our flock).
To me, the Buff Orps have personality very similar to a Golden Retriever: friendly, cuddly and calm. When I cuddle Lil’ Buff during the late afternoons (usually after 4:30pm, when they’re done with working the pasture), she’ll pet/peck my arms as if to mean, “I pet you, I pet you.” Unlike most other hens who sit (roost) in my lap, she prefers to be cuddled standing up.
She has taught me a lot of things about being a chicken keeper: becoming a broody hen and snapping her out of the broodiness; becoming infected with bumble foot and treating her infection with natural products (tumeric powder, comfrey leaves, tea tree oil foot dip) to heal her infection; becoming crop bound and using manual massage to break up the stuck crop. Currently, she’s not broody or bumblefooted nor cropbound.
I can immediately tell her apart physically from the other hens because she is missing a tine on her comb. She does not tolerate other hens’ bullying during meal time; she’s as headstrong as three other Australorp hens twice her size.
Her favorite treats are organic sunflower seeds with shells, coconut meat and yacon.
On the morning of January 29, we got a visit from a batch of kids from Honokaa Elementary. I got to spend a few hours with them, showing them many parts of the farm, teaching them about the trees and plants, the fruits and the tea, the chickens and the compost. They asked great questions and seemed to eagerly soak up knowledge and have a great time. “Best field trip ever.“
They felt the warm compost pile and learned about the billions of little microbes working hard to turn it into nutritious soil..
They got to really interact with the environment, picking fruit and carrots, smelling the cinnamon leaves, touching bugs, petting a chicken..
Funniest moment: I asked if anyone knows why there are so many wild chickens on Kauai. One girl, Pakalana, raised her hand and said, “Because there’s only one KFC?” (The common answer is “because there’s no mongoose.”)