Spring Springing & BioChar
In the last two weeks, the wheat fields out here greened up significantly and the millions of hard red droplets on the maple trees burst into bloom, getting us all very excited for spring to settle in (and back on our allergy management regimes).
We got a dry, warmish window last week to get some beds prepped and get our first round of cabbage, kale, broccolini, and lettuce plants in the ground, as well as some carrots, radishes, turnips, and arugula seeded. We're off to a good start!
In the meantime, we've spent a good amount of hours this winter clearing old barbed wire fence lines, brush piles, and thickets of invasive plants out of grazing areas, and we made a lot of burn pile material, so I just tried my hand at making Bio-Char.
I was inspired to try making Bio-Char by an article in Growing for Market, a monthly publication chock full of small-scale farmers' reflections, ideas, reviews, and descriptions of techniques and tools they've used. Bio-Char is just charcoal made from untreated lumber, brush, or timber. The idea is that instead of burning your brush all the way down to ash, you burn it in a low oxygen environment (managing a high temperature burn in a barrel with no oxygen coming in from the bottom) to make charcoal, stabilizing the carbon for, hopefully, centuries. The carbon is sequestered when you use the charcoal as a soil amendment, and the charcoal also provides structures, pore spaces, and ionized surfaces in the soil that, theoretically, increase microbial activity.
I've seen a few companies selling Bio-Char, and I've done a little research on it previously. I do not buy the idea of a Bio-Char industry, because harvesting forests for the express purpose of burning them into a soil amendment, or worse, a biofuel (therefore building an industry around this process), is antithetical to the goals of carbon sequestration (namely, mitigating climate change). The only time I think Bio-Char makes sense is when people are dealing with lots of brush piles, which happens to be our situation. We don't leave the brush piles lying around to decompose because they create dead spots in pasture, keep us from mowing the area, and allow more unwanted shrubs, trees, vines, or invasive blackberry to grow where they sit. So we burn them. I thought maybe making charcoal would be a better alternative than burning it all down to ash.
I also don't know, from the various study summaries I've read, if this stuff actually works! Is the carbon stable for thousands or even hundreds of years? Does increased microbial activity occur, and if it does, does it contribute to more rapid breakdown of humus in the soil and therefore a release of carbon that offsets the amount in the charcoal? Will the initial application of positively charged fine charcoal particles lock up available nutrients in the soil?
We're going to try amending one marginal section of one growing block in the field, and it may be decades before anybody can tell whether or not it was a good thing. How's that for delayed gratification?
I remember seeding tens of thousands of onions--four seeds per cell in plug trays--one cold, dark February with a farmer I worked for, and he said, "Farming is like counting to ten, really, really slowly." Those onions wouldn't be planted until early May, and they wouldn't be harvested until late August, and they wouldn't be distributed to CSA members until the winter months that followed, after curing. You know the steps, you just have to wait a really, really long time to get to each of them, and hold your place in your mind at all times. Bio-Char as a soil amendment seems like about the longest, slowest trial I've ever undertaken. It may even be that one lifetime isn't long enough to know the results.
Soon, though, with fields to till and seed and water and weed and--at last!--harvest, I won't have time to think about it.