Pete’s comments about burying or landfilling carbon black, brought to mind the amazingly fertile, enigmatic Tierra Preta of the Amazon basin.
https://en.m.wikipedia.org/wiki/Terra_preta
Terra preta owes its characteristic black color to its weathered charcoal content,[2] and was made by adding a mixture of charcoal, bone, broken pottery, compost and manure to the low fertility Amazonian soil. A product of indigenous soil management and slash-and-char agriculture,[3] the charcoal is stable and remains in the soil for thousands of years, binding and retaining minerals and nutrients.[4][5]
Does the “stable for 1000s of years” answer some questions about the utility of buring carbon black?
A new hypothesis for the origin of Amazonian Dark Earths
https://www.nature.com/articles/s41467-020-20184-2
Is this new hypothesis correct? IDK.
But, the carbon has been sequestered in these soils for a 1000+ years, these soils are acknowledged as significantly more fertile than the typical rainforest soil, and highly productive.
it makes me think that perhaps capturing CO2 in an appropriate carbon form, mught be used to improve farm land soils.
I’ve visited / toured experimental sites on which biosolids compost was added.
While there are definite benefits, the COSTS associated with composting, the aesthetics (smell and NIMBY) of the composting operations, the costs of buying, transporting, and spreading the compost were significant obstacles.
AND - EPA regulations regarding allowed amounts of nutrients (N, P, K; due to runoff water pollution) that could be spread on a given area, were at odds with the amount of compost required to achieve the compost benefits.
The EPA regulations (based on NPK content) permit something like 2mm of compost to be spread, while getting the soil and biological benefits require 5 to 10 cm.
Food for thought?
ralph