Calcium carbide releases acetylene gas upon its reaction with water that is further converted to ethylene in soil due to microbial reduction. Acetylene inhibits the activity of ammonia-oxidizing enzymes involved in the nitrification process, thus resulting in the inhibition of nitrification and denitrification processes and increase in the nitrogen fertilizer use efficiency. A series of studies were conducted with collaboration of Higher Education Commission (HEC), Pakistan during 2008-2011. The outcomes of these studies demonstrated the improvement in growth and yield of vegetable crops...