Tips on Composting from Will Bakx of Sonoma Compost

Sonoma Compost’s composting operation.

On Thursday at the National Heirloom Exposition, Will Bakx, soil scientist and operations manager of Sonoma Compost, gave a rapid fire lecture on the nitty gritty details of composting. Here’s some of his useful tips:

Temperature and Turning
Compost should stay above 131ºF for 15 days to kill pathogens. Bakx recommended getting a thermometer to check the temperature every day during the initial period and using Sonoma Compost’s handy Temperature/Turning Sheet (pdf) to keep track of the temperature of the pile. If the pile dips below 135ºF, turn it. If it doesn’t get up to temperature, add more nitrogen containing materials. If it gets above 163ºF, add more carbon containing materials. After the initial turnings just let it sit unless you have to turn to add moisture.

Bakx believes that you should turn as little as possible, just enough to achieve that first period of 15 days above 135º F. I really like the simplicity of this method and will definitely use the turning sheet the next time I build a pile. I really makes it clear when you should turn and how often.

Moisture
Lack of moisture, according to Bakx, is the number one mistake made by beginning composters. He suggested an ideal moisture range between 40-­‐60%. You can check the moisture level using the following technique:

Take handful of material. Squeeze firmly
Water escapes: >60%
Shiny ball: 55%–60%
Ball remains when tapped: 50–55%
Ball falls apart when tapped: 45–50%
No ball forms: 40–45%
Unless hand feels powdery dry: <40 p="p">

Bakx has drip irrigation set up on his large windrows, something I might try with my pile the next time.

Pile Size
The mimimum size for a compost pile is 3 x 3 x 3 feet or larger.

Things not to add

  • Ash–our soils tend to be alkaline in California and ash will raise pH. A small amount is ok.
  • Cardboard–Bakx is afraid of the glues and said that he is very conservative about what he ads to his compost.
  • Toilet paper–because of metals (I’ve been unable to verify this–if any of you know about this issue, please leave a comment.

Alleopathic plant material such as eucalyptus leaves and walnut leaves, on the other hand, are ok to add. Bakx cited studies where plants were successfully grown in leaf litter made entirely out of eucalyptus leaves. He suggested keeping such alleopathic material to less than 15% of the pile.

Web links
Sonoma Compost’s website: www.sonomacompost.com
Sonoma Compost’s Simple Guidelines to Composting (pdf)
Sonoma Compost’s Temperature/Turning Sheet (pdf)
An online carbon/nitrogen ratio calculator

Comopost, Compost, Compost

As if I didn’t need a reminder of how important compost is to a vegetable garden, note the tomato above. It’s on its way out, but it grew with no supplemental water in hard-packed clay soil contaminated with lead and zinc in a hot side yard. Why did it do well while the rest of my vegetable garden did not do as so good this summer?

Homemade compost.

I didn’t have enough compost for the rest of the veggie garden so I bought some at a nursery. The homebrew compost obviously had much more life in it. 

And life is the point. Soil is a living thing. Plants, particularly vegetables, need microbial life to thrive.

For more on the importance of microbial life read the USDA’s soil biology primer written by Dr. Elaine Ingham.

Does the scent of compost make bees angry?

I think I’ve stumbled upon a strange phenomenon: the smell released by turning compost pisses off bees. Yesterday was the third time this has happened to me. I took a sting just underneath my eye and another one to my right hand when I was turning a pile located about 15 feet away from a hive. Coincidentally, the same thing happened to a friend yesterday: he got stung while working with compost near a hive. Ordinarily our bees are reasonable about living in a small yard with humans–they are not even very aggressive when I open their hive. But apparently turning compost near them is a different matter.

I look like I’ve been in a fight. Lots of Benadryl today.

I have a theory. Bees are incredibly sensitive to odors and use them to communicate. Their alarm pheromones alert the hive to predators such as bears and people. Bee alarm pheromone consists of many different compounds. Interestingly, a lot of these compounds such as n-Butanol and Isoamyl acetate are byproducts of fermentation processes. I’m guessing that a number of these compounds are present in compost, and that when you turn a pile the act releases a cloud of compounds that mimic the bee’s alarm pheromones, causing them to attack.

It turns out that other lifeforms like to mimic honeybee alarm pheromone. Some species of orchids mimic bee alarm pheromone in order to attract pollination services. Small hive beetles, who raid beehives for their pollen, apparently bring with them a yeast that causes a fermentation process that mimics alarm pheromones. The small hive beetle’s fermented alarm pheromone, in turn, attracts more small hive beetles who quickly overwhelm the hive. These sorts of deceptive, symbiotic and parasitic loops in nature really amaze me. 

As a side note, I’ve only had compost pile related bee stings at this time of year, when honeybee numbers are at their peak and pollen and nectar sources are getting scarce (summer is hot and dry in Los Angeles and not much is blooming).

If you don’t have a hive, I doubt random, foraging worker bees would go after you if you are just turning compost in your yard. But if you’ve got a compost pile and are thinking about installing a hive–or vice versa–I’d seriously consider keeping the two as far apart as possible.

Am I alone in noticing this compost/bee alarm pheromone issue?

Composting at the NATO Protests in Chicago

Have you ever gone to a concert or a convention or some other large event and marveled at the staggering amounts of waste generated? I’ve been particularly wishing more of that waste was composted. And what do you know? Just as I was thinking about this, guest Root Simple blogger Nancy Klehm happened to send me a post on this very subject. If only every event had a compost tsar! Here’s Nancy:

I am obsessed with urban soil health, so when I got a phone call in mid May from Steven of the Seeds of Peace Collective, I realized a soil ship had floated in. Seeds of Peace is a collective of accomplished cooks and trained street medics, based in Missoula, who provide delicious home cooked food in support of non-violent social movements. They were in Chicago to set up a free community kitchen to serve thousands of NATO conference protestors. Steven said they needed my assistance with their food waste as they had already overwhelmed a small urban garden’s compost bin.

It was late, so I waited until morning and drove my pickup to their site – a parking lot between a community center and an auto parts store. The scene was impressive: a maroon biodiesel school bus with windows dressed in curtains screen printed with frying pans and butcher knives and the largest wok and cast iron pan I have ever seen. A purple tent stretched from the bus into the lot overhanging a to-code outdoor kitchen with multiple burner stoves, wash sinks, prepping area and boxes of produce, mostly organic. At least 12 people stood prepping food for the day. Gallons and gallons of salad and stir fry ingredients were being tossed and mixed in 30 gallon coolers with small wooden oars.

Every day for a week, I picked up the 100 or so gallons of food waste a day and provided them with extra large garbage cans to pour their waste into. Their kitchen was three miles from the rallying area. Once the food was prepared, they would pack a flat bed with it and a few tables and trundle off to the park to serve their healthy, delicious food free of charge.

One pick up was an entire garbage can of delicious looking chickpea and sweet potato curry that had fermented in the sun due to the police blocking their passage to the Park. It made me cry to compost that delicious looking curry. I had to use a couple of bales of straw and dumpstered cardboard from my carbon stockpile to take care of so much nitrogenous waste. Over the past month, the pile, well integrated and covered with a thick layer of straw reached thermophilic temperatures and now is in its mesophilic stage. Most of the food is just residual moisture now and the pile has dropped in volume by at least 20% due to composting and evaporation. So much future soil!

Thanks Steven, Sarah, Patrick and the rest of you of the Seeds of Peace Collective. May you meet with strong hearts and hands on the road.

Healing the yard with a huge compost pile

The new compost pile is covered with a tarp to keep moisture in. Eventually it will fill this whole space. In the background you can see our leftover adobe bricks.



So–our regular readers will know that we have high levels of lead in our back yard soil. We’re dealing with this by filling most of our yard with mulch and perennial natives to lock down the soil (lead laden dust is bad) and to diversify the local ecosystem.

Meanwhile, our vegetables must be grown in raised beds from now out. We used to have two main vegetable beds in the center of our back yard–they were our workhorses. Since the lead scare we’ve pulled up those beds. They were semi-sunken beds, the soil in them a mix of native soil, compost and imported soil.

When you have contaminated soil yet want to grow food, the easiest solution is to build extra deep raised beds and fill them with imported soil (soil which has, hopefully, been tested for lead!). Some people put plastic sheeting or rock barriers between the imported soil or native soil, which in effect makes the beds into giant containers.

We did something a little different–and a lot harder. We dug out a huge pit where our beds used to be. When I say “we,” I mean Erik dug a huge pit. (Somehow I weaseled out of this project.) This excavation had two purposes: 1) to remove the topsoil, where most of the lead (lead being an airborne pollutant) is located and 2) to harvest the clay beneath to use in our earth oven. Between the clay harvested for making the adobe bricks and cob, and the supplemental clay that we’ve put aside for future repairs and maintenance on the oven, the pit has grown to be about 12 feet wide and 2 feet deep.

This pit is going to be our new planting area, but obviously it needs to be filled in. Instead of buying imported soil, we’re going to grow soil by composting on a grand scale. We’re going to compost right in the pit and fill it up bit by bit. When it’s done, we’ll have a big round area where it will probably be safe enough to plant food crops. Might the plants suck some lead up from the deep clay layer? Maybe. We could test the deep clay. Might some lead leach in from the sides of the pit? Possibly. But this solution is good enough for us.

What drives us to this decision is our intuitive relationship with our yard. I know that sounds a little woo-woo, but I encourage you all to pay attention to what your gut tells you about your gardens. It won’t steer you wrong.

Our gut instincts told us to dig down rather than build up, and to make good use of excavated dirt in the oven. Now our instincts tell us to fill this giant hole with rich homemade compost rather than imported soil. It just seems more…holistic to grow out own soil. It will rise out of our meals, our labor, our intentions. It will belong to this place.

How long will this take? Probably about a year. Maybe more. We’re willing to wait for those future harvests because this feels right.

Disconnect to Reconnect: Ditching the “Flushie” for a Composting Toilet

Image from the Wikimedia Commons

We’re lucky to have another guest post by Nancy Klehm (see a nice interview with her on foraging here). Nancy visits us at the Root Simple compound at least once a year. What follows is an account of a plumbing misadventure she had on her last visit. 

To give you some context, ever since we’ve remodeled our bathroom and switched to a low-flow toilet we’ve had periodic backups. We think there is a low spot just within reach of our turlet snake. The toilet flushes OK most of the time, but at least once a week I’ve got to deploy that damn snake.

Here’s Nancy:

I don’t use a flushie often, I made the decision to ‘go dry’ years ago, adopting the bucket toilet + sawdust system as it pairs nicely with my composting obsession and food growing habit.

I stayed at Erik and Kelly’s back in February. Their low flush toilet and antique piping can’t seem to handle even the most modest bodily donation. Once a flushing attempt proves unsuccessful, and immediately following the ‘oh no…’ guilty grimace, a light-hearted blame game plays out and then according to homestead rules, Erik snakes the toilet. The closet augur is kept on the front porch (to greet visitors?). Erik augers for a few minutes, flushes successfully, marches the tool back outside to air out and we settle back into our routines relieved that our burdens are flowing into the larger mystery of pipes and their soupy contents to the municipal waste treatment plant miles away.

But with Erik and Kelly out of town on one of the weekends during my stay, the daily chores of feeding the kittens, letting out the single hen to roam the yard and snaking, if so needed, fell on me. And yes, the toilet clogged and no, I did not assume the blame. I am regular enough (2-3x/day) as are Erik and Kelly for the record [editor's note: the editors demur from either acknowledging or disavowing the hypothetical frequency of their natural propensities.] to avoid creating such monsters and yet, the flushie needs snaking every day soon after the post-caffeine effect.

Continue reading…

The Stages of Alchemy as a Metaphor for Composting

I’ve been struck, for a long time, at the connections between alchemy and composting. I thought it might be interesting to “thoughtstyle” on the alchemical process and what it has to teach us as a metaphor for composting. Though there’s not universal agreement on this, western alchemy is often divided into four stages identified by color:

Nigredo or blackening
“The ever deepening descent into the unconscious suddenly becomes illumination from above” as Carl Jung put it. In other words, you have to go down to go up. When you work with compost you’re literally working with poop, waste and trash.

Albedo or whitening
The nigredo stage is purified by the fire of thermophilic bacteria and transformed into the albedo or “whitening”. The dark night of the soul has concluded as the trash (poop!) in our compost pile are now a living, breathing collective entity.

Citrinitas, the yellowing
Connected with the symbolism of the sun it’s a reminder that all life, including the microbes, fungi and insect life of the compost pile are ultimately (somewhat tangentially in the case of fungi) connected to the solar power of the sun.

Rubedo, a reddening
At the final stage, the rubedo, a multiplication takes place – life pervades the compost pile in a highly concentrated form. Lead becomes gold and, in fact, everything the rubedo touches becomes gold. The same goes with our compost. Everything it comes in contact with is pervaded with microbial life.

At its heart, alchemy is a metaphor for spiritual change. When we compost, we’re participating with and accelerating one of nature’s miracles: the transformation of waste in to life. Compost, then, is the spiritual, life-giving transformation of the planet.

Compost pail failure

We have one of those standard, stainless steel compost pails–the kind you keep on your countertop to collect scraps. It’s a couple of years old. Last week, it began to leak from the bottom. This mystified me because a) it’s stainless steel and seemed a quality item and b) it had no seams on the bottom. For a while I wondered if there was a miracle at work–you know, sort of the composting version of a weeping Virgin Mary. But today I took it into strong light and found one teeny tiny hole and pits that look like they soon will be holes, too. I assume the pitting is a caused by the acidity of the compost juice?

Has anyone had something similar happen?

Our consultants agree it smells fascinating.

Cat Poop Compost Installment #2

Drum full o’ cat litter

WARNING: Human waste and cat waste contain dangerous bacteria.  I fully believe that composting is a safe and sane solution to a waste stream problem–that’s why I’m writing about it, after all– I also know that it can be handled badly. (The stories we hear!) So please, read up on the subject before starting. You should have a solid foundation in regular compost to begin with, because all the basics apply. Take a good composting class or find a compost mentor. Read the Humanure Handbook. For complete safety, all cat/human waste compost should be allowed to sit for two years, and it should not be applied to food crops (but it can go around fruit trees).

***

Last year at the end of July I posted about our experimental cat litter composting solution in The Cat Poop Portal post. It’s been a while since we reported in, and I’ve received some gentle pokes from readers, so this is an update.

Long story short, it’s going slowly. At the time of the last post we’d installed a 50 gallon drum in our side yard. That drum filled up fast. We have two indoor cats now (I think we only had one when this started) and they are slinky little poo machines. Also, we were using pine pellets which require a complete change-out more often than clumping litters, so we managed to fill the drum in about four months. That was faster than I expected, and a little disappointing, but there are two ways to ease this problem.

1) Changing litter, so we use less. Most clumping litters are either clay-based, which is not good for compost, or have sketchy chemicals in them. We’ve recently found World’s Best Cat Litter, which is a clumping litter made of corn. I called World’s Best to make sure there was nothing added to the corn, and they promised me that there’s nothing added to the standard formula–the magic is all in the way the corn is processed. So yes, we’re supporting Big Corn…but what are you going to do? The stuff works really well and is compostable. Now that we’re using it we’ll reduce our overall litter waste volume.  (Of note: our friend John, a madman with six cats, swears by Swheat Scoop, which is wheat based. I don’t find it works for me, but he blames my litter management skills. It’s an alternative.)

2) We’re offloading half-finished cat compost to My Big Fat Worm Bin. Regular readers (and Vermicomposting workshop participants) might remember that composting expert Nancy Klehm had us add a good amount of mature cat litter compost to the mix when we built up the bedding material for the worms. She said she wouldn’t want to foist raw cat litter on the worms, but when it was well broken down they could handle it.

The drum has been, shall we say, resting productively over the winter. Today I went and dug it up to see how it was doing. As with any pile, the stuff on top was less finished–it looked pretty much like a cat box. It isn’t stinky, though, as long as I make sure all the cat poo is buried.

Down lower the material was more broken down. It’s an interesting rusty orange color. But I didn’t get the sense of lots of activity going on. It was a cool pile, and it showed very little insect life. This is not necessarily a bad thing. The pile is decomposing, just on a long timeline. But at this rate of decomposition I suspected it would need at least another year of sitting to be fully broken down, and then it would need to rest even longer for safety. Compost made from carnivore and omnivore poop needs a two year cycle to allow the pathogens to die off.

Digging down all I see is decomposing red sawdust

Wanting to move it along faster, I did what I’d do for any compost pile that was a little pokey: I turned it, and added nitrogen and water.* Shoveling 50 gallons of kitty litter is exactly what I want to be doing on any given Saturday! As I shoveled, I decided that if I didn’t already have Mad Kitty Disease, I’d have it by the end of the day. As if to confirm this, Trout sat in the bedroom window over the poo-bin, wearing a peculiar, self-satisfied expression while he watched me slave away over his waste. (Phoebe didn’t join in, because she doesn’t admit to creating waste at all.)

Okay, he doesn’t look smug here because he’s wondering what I’m doing with the camera. Prior to this I assure you he he looked very smug.

But back to business. For those of you who are new to composting, turning a pile stirs everything up, increasing bacterial activity, making the materials hotter. This speeds decomposition. There’s much debate over whether to turn or not to turn and how often to turn, and I’m not going into any of that right now, except to say that humanure piles are not usually turned, and I’d hoped not to do so with this catmanure pile, either, but necessity drives.

Just like turning, adding a nitrogen source to the pile heats it up. All compost piles are a balance between carbon and nitrogen sources, aka “greens and browns.” Too much carbon and your pile is cool and slow. Too much nitrogen and its slimy and stinky. But if you get the balance right, you end up with lovely compost.

In kitty litter composting, the litter is the carbon and the urine and poo deliver the nitrogen. Starting out on this path, I had no idea how the natural carbon to nitrogen ratio in a cat box would play out. Now it seems to me that the ratio is carbon heavy. Cat litter materials, such as compressed sawdust, are really dense carbon sources and need tons of nitrogen to balance them.

So my preliminary finding on this point is that it might be help to add extra nitrogen when you add a new layer of litter. Extra nitrogen could come in the form of green yard trimmings, veg scraps, urine, fresh horse manure, etc. Today, though, I decided to add alfalfa meal because we had some wasting away in the garage. Alfalfa meal is ground up alfalfa. It’s used as a natural fertilizer and top dressing, and is high in nitrogen. Generally speaking, I think nitrogen should be free, but if you don’t have a lot of scraps/trimmings/spare urine around, you could do worse than to have some alfalfa meal on hand to perk up your compost pile if it’s gone carbon heavy.

Mixing in the alfalfa meal and water

When it was all done, I thought my pile looked a little more loved, and I think it’s going to heat up nicely. I was able to move ten gallons of the more mature compost over to the worm bin, but the barrel is still pretty close to full.

Adding the kitty compost to the worm bin

For the near future we’ll probably be able to send about half our litter to the barrel, and the other half will have to go to the landfill. Eventually we’ll get rid of this big mass of pine litter, and I hope that by using the clumping litter will keep the bin from filling up quite so fast, and will somehow reach cat:compost equilibrium.

*To be clear, I added water because the pile was dryish, not because water in itself is a magic activator to be used in all circumstances. If a pile is too wet, I’d blend in dry stuff while turning. The goal is for the materials in the pile to be about as wet as a wrung out sponge.

Other People’s Poo: Biosolids in the Garden

It’s people!

Why not use city compost in your garden? Ecological designer Darren Butler, at a class I was sitting in on, showed a soil report from a site that had used compost from the city of Los Angeles. LA’s compost contain biosolids, a euphemism for sewage. The soil test showed high levels of:

  • zinc 196 ppm
  • copper 76 ppm
  • sulfur 5,752 ppm

The problem isn’t human waste, it’s all the other stuff that ends up in the sewer. I see a future when we’ll be responsibly composting human waste (see Joseph Jenkin’s website for how to do that). But watch out for that free city compost.

Update: A blog reader, Helane Shields, left an interesting series of links about biosolids in the comments. Thanks Helane!