The Hong Kong government is forging ahead with a plan to improve Tsui Keng, an agricultural district north of the city’s urban areas. The project involves work to improve drainage, irrigation and access, but it has been met with opposition from farmers who say it might do more harm than good. Farmers who have worked the land for years say they worry about pollution from construction work, and have accused the government of clearing their fields without enough notice. But the government says it…