sentences:  Farmer's zeal to clear more land for maize cultivation has led to deforestation of vast tracts of hillsides, resulting in "bald mountains" (; ).A by-product of the land clearing is smoke from field burning, contributing to the northern region's significant air pollution.Charoen Pokphand (CP) Group, Thailand's largest agro-industrial and food conglomerate, and the leading purchaser of Pua District maize, in March 2016 announced an "agricultural social enterprise" to steer district villagers away from maize farming.