Accomplishments

- Through synthesis of research findings from several years of research in partnership with the NARES, the principles of SSNM were developed into an overall conceptual framework for the research on and delivery of improved integrated nutrient management.
- The SSNM approach optimizes the use of nutrients from soil, crop residues, and manures. It integrates the use of the leaf color chart (LCC) for plant need-based N management. It  uses nutrient omission plots for plant need-based P and K fertilizer management to ensure the application of a balanced ratio of N, P, and K.
- The principles of SSNM were incorporated into training materials for a 3- to 4-week IRRI course on integrated nutrient management. Additional training materials were developed in partnership with the impact workgroup to promote the principles and components of SSNM for wide-scale evaluation and promotion. 
- The refined SSNM approach was disseminated beyond RTOP via conference papers, nontechnical publications (Better Crops and Better Crops International special publications), and a prototype pocket guide on nutrient management (in collaboration with PPI-Singapore). 
- The recognized SSNM approach is now ready for on-farm evaluation and promotion with NARES partners in many Asian countries.
- On-farm and on-station experiments were conducted to identify and refine the most promising N management options for specific locations of intensive rice production at RTOP sites in China, India, Indonesia, the Philippines, and Thailand. In addition, research began at three additional sites in China in 2001. 
- The research findings at many of the sites, and particularly in China, reveal considerable potential to modify existing farmer practices to achieve the same or higher grain yields with less N fertilizer.
- Fertilizer K recommendations are being reevaluated in on-farm experiments in India and Thailand following an improved nutrient balance model.
- Differences in K requirements of inbred and hybrid rice were evaluated through research of a PhD scholar in Jinhua, Zhejiang Province, China.
- The synergy of integrating improved nutrient management with improved crop management was evaluated in Vietnam (Red River Basin and Mekong Delta) and Indonesia.
- An awareness of the inefficiencies of current N fertilizer management practices and opportunities to increase productivity and yield through improved N fertilizer use in combination with balanced P and K fertilization have been highlighted with NARES partners in several countries.