Chernozem soils, called mollisols in the Americas, are black-colored soils containing a high percentage of humus (4% to 16%) and high percentages of phosphorus and ammonia compounds. Many earthworms contribute to the good soil structure and the qualities of the soil. Biodiversity and the abundance of organisms is high, and they are active at greater depths than in other soils. Such soils also contains a lot of calcium, so they do not easily become acidic. They are typical of grasslands in continental climate belts with cold winters, rainy springs and hot summers.
As discussed on this SE site, a major theory about their formation links them to the fine mineral material left after glaciation: How can poor tropical soils be enriched by biological means?
These soils are the most productive in the world. They account for one quarter of the world's total soils. They can be linked to Ukraine's role as a major breadbasket for the world. Before the current war (which started in February 2022) Ukraine produced 40% of global wheat and 47% of global sunflower oil, from around 1% of the globe's arable land. This can be linked to the motivations of the current conflict there with Russia.
Can we generate new chernozem soil? What glaciers have done, we could now do mechanically. High soil carbon and humus can be generated, like with biochar and vermiculture. There may be limits in relation to biodiversity with temperature and humidity ranges. But can new chernozem be generated, where it can be sustained?
This could ease conflicts over food and agricultural land. And substantially contribute to the draw down of carbon for climate targets. It also seems like we would want soil like this to successfully colonise Mars. Can we make it? Is anyone doing so, or trying to?
I would note for comparison, anthropogenic terra preta, in the tropical Amazon Basin.
Seaweeds like giant kelp are also an interesting source of nutrients, that could help mop up agricultural run-off of phosphorus in particular, and be directed towards soil improvement.