Abstract: The System of Rice Intensification (SRI) is a production system that involves the adoption of certain changes in management practices for rice cultivation that create a better growing environment for the crop. This system was compared with conventional practices and assessed under organic and inorganic management. SRI practices showed significant response in root number, effective tillers per hill, days to flowering and Harvest Index. In addition, SRI was found effective in minimizing pest and disease incidence, shortening the crop cycle, and improving plant stand. Grain yield was not different from conventional method. Except for harvest index and plant lodging percentage, there were no significant effects from management treatments. Synergistic responses were noted when SRI practices were combined with organic management for plant height, number of effective tillers per hill, days to flowering and to maturity, improved panicle characteristics, lower plant lodging percentage, and higher harvest index that ultimately led to comparable grain yields. Net returns increased approximately 1.5 times for SRI-organic management regardless of the added labor requirements for weed control. However, comparatively higher grain yield from conventional-inorganic methods underscore the need for further investigations in defining what constitutes an optimum sets of practices for an SRI-organic systems specifically addressing grain yields, and weed management.

Key words: system of rice intensification, conventional practices, organic and inorganic management, rice growth