Biochar, a charcoal-like substance made from heated organic biomass such as forest and agricultural waste, is the subject of several research studies now underway on Maine farms. When added to tainted soil, it is showing promise in reducing the uptake of forever chemicals in crops, researchers said. It can store water that it then releases during droughts. And it can increase nutrient retention in soil and boost carbon sequestration, according to the American Farmland Trust. If the current research tackling those huge challenges to the food supply bear fruit, the market for biochar could boom. And Maine is getting ready for that. In October, the second biochar producer in the state started commercial production. …Standard Biocarbon’s factory in Enfield, in Penobscot County, claims to produce organic biochar that is clean, so it doesn’t further pollute farm fields already contaminated by per- and polyfluoroalkyl substances, or PFAS, he said.