Image credit: NRCS Oregon/Flickr (CC BY-ND 2. ” In Pukekohe, Isaachsen says, crop farmers using biochar in their soils haven’t had to use as much fertiliser to achieve the same yields, and haven’t had to replenish truckloads of soil that were previously washed away by rains. The government is set to announce a review of how best to deal with slash this week (paywall) \u2013 perhaps biochar will be on the table