Yes it is. That and the Osmocote fertilizer. In 3 years I went from mostly clay to rich friable soil that helps produce volunteer flowers in my beds that I just move to wherever I want them. I fed the bees all the way to November last year and had ageratum through December just in time for my Yuletide Camellia’s to bloom.
I’m working terra preta into my sand plan. Anything that gets pulled up becomes mulch or compost. If you haven’t tried a garbage can bio-reactor I highly suggest it. You can cook eggs in mine it gets so hot. Next year should be very fruitful, and it’s looking more and more likely that we may need the supplemental food.