LAHORE - The Punjab Agriculture Department has advised farmers not to burn paddy stubble as it is an improper way to get rid of crop residue. A spokesman for the department said on Sunday that burning crops residue causes smog, which was a dangerous type of environmental pollution. He said that smog leaves negative impact not only on humans and animals but also on plants. High-level of smog affects the growth of plant, he added. He further said that growers should avoid burning paddy stubble as this harms the fertility of the land.