Summarize what the researchers did to improve the quality of post mining site soil

The researcher centred on the potential uses of biochar, charcoal primarily used for agricultural and to improve the quality of post mining sites.

A method called mountaintop removal was used by mining firms. This means that they remove rock and mineral deposits off the top of the mountain to gain access to within the coal seams. The resulting soil is infertile and strongly acidic. The compacted soil after mine proves harder to  bring seed into the soil.

The researchers  try to use biochar to help reforest the soil at the post-mining site. Before it was reseeded and replanted, they got permission to add a layer of biochar to a post-mining site. the team created “planting cells” of biochar‐enhanced soil on the post‐mining site and that showed improvment in the sapling growth.

im not intirely sure but i think the anwser is d relative humidity