One of the primary purposes of biochar is to restore and improve the soil conditions. As a “hotel for microorganisms”, biochar brings life into the topsoil and allows the rhizosphere to flourish. This results in significantly healthier plants without the need for conventional fertilizers.
If land restoration is your goal, then it’s impossible to overlook the value of bamboo. This tenacious grass requires little in the way of nutrients and is able to gain a foothold quickly. As it does so, bamboo binds the soil and prevents erosion. In addition, the fallen leaves and healthy roots contribute to the humus and bolster the topsoil.
As such, biochar and bamboo really go hand in hand. Not to say that you should uproot your garden or clear the forest and replace it with bamboo. But in areas degraded by flooding, clearcutting, mining, and other disasters — either natural or manmade — bamboo and biochar both have the special ability to restore life.
The two are also especially effective for soil remediation. In areas of heavy pollution, where the landscape is tainted with petroleum or chemical runoff, biochar and bamboo have been shown to extract these toxins and make the soil more hospitable for farming.
Higher quality biochar
On the question of whether bamboo produces a better quality of biochar than other feedstocks, the verdict is still out. I’ve spoken with a few bamboo enthusiasts who insist that bamboo biochar is the best, and I’d like to believe them. But at this point, I’ve not seen any solid scientific evidence to support this theory.
On the one hand, bamboo is woody and dense, with relatively high levels of carbon. And compared to other woody biomass like trees, bamboo burns more quickly, because the poles are generally hollow. This makes the pyrolysis process more efficient.
On the other hand, some claim that bamboo makes better biochar on account of other traits like its porosity. It’s important for biochar to be porous, but it’s not clear whether that characteristic carries over and results in any difference with the finished product.
I have also heard it said that bamboo’s high silica content gives the biochar a higher cation-exchange capacity. More negatively charged soil particles will attract more nutrients that are positively charged, thereby increasing the soil fertility. Again, I’ve not seen any hard evidence to confirm this conjecture. Supposedly, the high silica profile also leads to better quality wood vinegar, one of the numerous co-products that can be collected during pyrolysis. This is according to Michael Wittman of Blue Sky Biochar.
The most important reasons to advocate for bamboo as a biochar feedstock are pretty similar to the reasons we endorse bamboo in general. For carbon sequestration and renewability, nothing quite compares to bamboo. And since carbon removal is one of the key benefits of biochar, it makes a certain amount of sense to pair the two together.
But is bamboo biochar going to make a bigger impact on your soil quality and your crop yields than other biochar? Probably not. In the end, as long as you’re adding biochar, the difference to not using biochar at all is going to be the most striking comparison. Still more scientific documentation is required in this area as well, but we’ve seen more than enough evidence with our own eyes to be thoroughly convinced.
And at the end of the day, when it comes to making biochar, it’s not a competition. The point is to do what makes sense with the available resources in any given environment. It’s all about regenerating agricultural land and converting waste into something of far greater value. So use what you have, and do your best to leave the land better than you found it.