ROSEBURG Biochar expo set at park Gardeners, farmers, woodland managers and others interested in attending the Biochar Expo 2012 have until Monday to register for the Oct. 20 gathering at the Master Gardeners’ Discovery Garden. The event takes place from 9:30 a.m. to 1 p.m. at the garden near River Forks Park west of Roseburg. The expo includes demonstrations on choosing wood to make charcoal, fabricating barrels to heat wood for charcoal, selecting a pyrolysis technique, pulverizing charcoal to make biologically active biochar and applying biochar to garden, farm and forest soils. An 11:30 a.m. program will focus on testing …