This publication is intended to enhance rice production and provides information on best management practices. The role of isotopic techniques to quantify nitrogen use efficiency is addressed and information presented to support a better understanding of the pathways of greenhouse gases emission. The publication informs the reader on improved rice varieties and sustainable cultivation practices from a wide range of Asian countries. This will enable national research and development staff to select and test these varieties and practices in farmers’ fields to promote improved rice varieties and crop management practices in the respective countries. By using these improved crop management methods, farmers can improve the productivity and profitability of rice crops through the adoption of locally adapted “best’ rice varieties, thereby protecting the local environment.