The Emerging Technologies Appendix does not mention biochar, but the 2015 plan update has a paragraph in the Emerging Technologies chapter, saying
biochar is made "by heating vegetation slow without oxygen"(it's made by heating a carbonaceous biomass, e.g. wood, ag waste, manure, fast or slow with little or no oxygen, depending on the process). Inputs could be "lumber waste, dried corn stalks and other 168 Maryland Department of the Environment plan residues."
"The resulting biochar... can be placed in the soil as fertilizer."(It is a soil amendment, which improves many soil properties, including preservation and reduction of added fertilizers.)
"However there are some risks to keep in mind to ensure that it remains carbon negative and doesn’t harm the soil it is meant to be fertilizing."Rarely would biochar cause lasting harm to soil. The long term benefits would outweigh short-term yield reductions.
"Biochar must be used in soils of similar pH or else it can have a negative effect on soil fertility."Biochar could change pH in the short-run, but these changes are predictable, depending on the biochar feedstock and production method, and it can be applied discriminately.
"If the biochar is made from forest ecosystems, the result could be a net increase in greenhouse gases."That final jab is the bugaboo that many biochar skeptics raise, fearing deforestation as an industrial means of obtain biochar feedstock. Sustainable forestry should trump biochar production as a general principle in crafting environmental regulations, but the two are far from mutually exclusive. It's also a reason why economies of scale should not be allowed to run rampant in the biochar industry.
Positive publicity about biochar is growing. An authoritative article in Nature last week pointed out that the theoretical potential for soil to sequester carbon is 80% of the rate at which it is currently being added to the atmosphere by humans. That sure makes the Maryland Climate Change Commission carbon farming target of 0.4% look weak. The French initiative, 4 pour 1000, adopted by several other countries at the Paris climate conference, to increase soil carbon 0.4% through carbon farming is another inducement to put biochar on the entrée menu.