Anyone used biochar before?

[seiyafan]

I am thinking of topdressing the sandy part of my lawn (actually mostly just sand) with biochar instead of peat moss, does anyone have any experience with it? Here's one place that sells it: https://www.wakefieldbiochar.com/

[MorpheusPA]

I can't see that it would hurt in reasonable amounts (overuse of ash and char can lead to buildup of heavy metals due to the mass required and the fact that metals don't tend to volatilize).

I object far less to 1" of char than I would to 1" of ash, of course, as the char is far less likely to sterilize the soil until the salts wash out...

That having been said, we don't know how terra prieta was created. Slash and burn agriculture was part of it, but only part, and obviously not the most important part since we do that in many places and don't end up with soil like that.

At $30 per cubic foot the price is...I don't use that kind of language most of the time. I might get a small bag and try it in a semi-controlled houseplant experiment, but...

Find a local woodworker and see if they'll let you cart away the sawdust from their untreated wood (most will as it costs them to get rid of it). Only use untreated. Spread that on your lawn and gardens and let the natural oxidization processes "char" it for you over time. It's free. I'll give you leave to use up to 200 pounds per thousand square feet per year, although you might want to add a bit of organic (or synthetic) nitrogen if you go over 50 to speed decomposition.

[seiyafan]

Thanks, what about earthworm casting? Would that be too much of a luxury?

[MorpheusPA]

I'd just feed the worms and let them make castings. Any organic does great for that!