Use of soil health card has helped farmers substantially reduce the cost of production and achieve higher production, thereby increasing farm income up to ?30,000 per acre, depending on the crop, according to a government study.   The study, conducted by the National Productivity Council (NPC) in 76 districts of 19 States, covering 170 soil testing labs and 1,700 farmers, has been released on the completion of five years of the government scheme. Better productivity Soil health card provides information to farmers on the nutrient status of their soil along with recommendation on appropriate dosage of nutrients to be applied for improving its health and fertility.