Amending with biochar is a very good way to jump start the soil life, but regenerative agriculture should go much further than that. There's a bunch of techniques developed in the last few decades, notably permaculture and syntropic agroforestry, as well as techniques for preventing erosion in difficult topography such as keyline planting and scales.

But for the soil to be really alive, lots of plants must be planted, in a polyculture context. It's the photosynthesis that feeds the soil's fauna, which then support the plants, increase fertility and carbon content.