Charging with EM, etc

This is an excerpt of a blog from Kelpie Wilson, who might be the most famous maker of biochar in the world.  You can get her blog just by searching for her name, blog and biochar.  

She makes an important point about how to save EM(Effective Microbes), so that it doesn't mold, if you want to use it to charge your biochar later.

John S
PDX OR

Walking out into the field, I spied numerous ground squirrel mounds. These are our groundhogs and they have been active this winter, plowing up the ground. You can see new seedlings sprout in the freshly tilled earth. I could also see the good work our rodents had done to till in biochar from our biochar burn pile patches.

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Ground squirrel diggings incorporate biochar into the soil.


Barney the barn cat joins us on our walk in the field to inspect biochar patches. He does a great job of keeping ground squirrels out of our garden and confined to the field where they belong.

In the forest, I have noticed that abundant leaf litter quickly covers biochar patches, adding organic matter, so soil forms more quickly. The field is different. Leaving thick patches of biochar in our field tends to suppress annual grasses. The perennial bunch grasses and forbs have no trouble growing up through an inch or two of biochar mulch, but the annual grasses are easily suppressed. That’s good to know if your objective is to suppress invasive annuals, but I am not sure if that is a good thing in our field or not. I don’t know that much about grasses, although I do know that we have a lot of non-native grasses.


The abandoned car is a great place for a predator to spot rodents in the grass.

The field is really a sparsely populated oak savannah and nobody grazes there but deer and rabbits. One of these days, we hope to do a broadcast burn here to see if we can help encourage the natives and discourage the invasives.

Meanwhile, back at the garden, I am preparing fertilizers and ferments for seed starting. The first project was an experiment to ferment biochar with bokashi. I have done this a lot of different ways but this time I took a five-gallon bucket of wet bokashi (wheat bran fermented with molasses and EM-1) and mixed it with an equal amount of fine grained biochar and fermented it in a sealed tote for another two weeks.

Normally what I do is dry the bokashi by itself in the greenhouse and mix it with biochar later. It’s important to dry the wet bokashi once it is done fermenting, or else it can mold. Dried bokashi can keep for years, staying biologically active. But since I made the bokashi late in the fall, greenhouse drying was not going to work very well. I figured that if I mixed it with biochar, that would help it dry faster.

Well that worked out just great. The extra two weeks of fermentation with the biochar baked a lovely biochar-bokashi cake. The bacteria infused into the biochar and bound it all together with actinomycetes mycelia, which are filamentous, branching networks of hyphae that resemble fungal structures. While they are prokaryotic bacteria and not fungi, they grow as a network of thread-like filaments that can differentiate into aerial mycelium and substrate mycelium to absorb nutrients and produce spores (according to Wikipedia).

Now after a week of drying in the greenhouse (it has been sunny), these lumps are all dry and ready to safely store for use in my compost buckets and in soil mixes.


Biochar Bokashi cupcakes for the compost.


This is the original wet bokashi, still in the fermentation bucket. I mixed this with biochar and fermented for another two weeks before drying.

I have also been busy preparing my potting soil for seed starting. I learned a lot about compost extract from Matt Powers and his guests last month at R Future and I decided to try it for my potting soil. I usually just add compost to the potting soil because I want beneficial microbes to be present right at the start of the plant’s life, but that comes with a cost - sprouting weed seeds that compete with my crops.

I took some inspiration from this recipe for compost extract that calls for adding nutrients to your finished compost and letting it feed and multiply the microbes for a day or two before extraction. Then you take this enhanced compost and add it to a bucket of water and stir for awhile. I stirred for 5 minutes, let it sit for an hour and stirred for 2 more minutes before straining out the solids. I then added the liquid to a plain peat potting soil.

Compost extract is different from aerated compost tea. It make more sense to me because you are growing microbes that live in soil, not the ones that thrive in water. I have made compost tea before with an aquarium bubbler and then looked at it under the microscope. It did not appear to have a huge abundance of microbes. When I examined the compost extract I made, it was pulsing with all kinds of tiny critters. I don’t really know what I am looking for, though I can tell a yeast from a bacillus, but these guys were all living in my compost, and I know my plants like that.

So far I have started lettuce and onions in potting soil enhanced with my compost extract. Only the lettuce has spouted and it looks good. No weed seeds. I will keep you posted. In the meantime, Happy Spring!

Also, if you don’t have enough biochar in your life and you would like to just make it yourself, check out my spring sale on the Ring of Fire Kiln. Use code KWROF to get $100 off your kiln order.



Also, if you want to learn more about practical biochar tips and tricks for growing your own food, or you are interested in stewardship biochar for restoring natural ecosystems and biodiversity, check out some of my links