The world is confronted with one of the most difficult tasks of the twenty-first century, satisfying society’s expanding food demands while causing agriculture’s environmental impacts. Rice security is the food security for South Asian countries. Rice production requires a large amount of water and fertilizer, especially nitrogenous fertilizer, where urea works as the primary source of nitrogen (N). Different biogeochemical conditions, such as alternate wetting and drying (AWD), intermittent drainage, agroclimatic condition, oxic-anoxic condition, complete flooded irrigation,. have severe impacts on GHGs emission and nitrogen use efficiency (NUE) from rice fields. For sustainable production, it is a must to mitigate the emission of GHGs and increase NUE along with cost minimization. But analytically accurate data about these losses are still not quantifiably justified. In this chapter, we will show the proper use of the measured data with suitable results and discussions to recommend the future cultivation system of rice for sustainable production.