Development and impact of site specific nutrient management in the Red River Delta of Vietnam

Site-specific nutrient management (SSNM) for a more effective use of fertilizers in rice production was developed and validated in the Red River Delta (RRD) of northern Vietnam through a partnership of the Soils and Fertilizers Research Institute (SFRI) and the International Rice Research Institute (IRRI) beginning in 1997. The subsequent dissemination of validated SSNM practices involved collaboration of SFRI and IRRI with the extension system and Plant Protection Division (PPD). We review the development of SSNM in the RRD and estimate the impact of SSNM adoption at the farm level through a survey in 2007 of adopters and nonadopters of SSNM in Ha Nam and Ha Tay provinces. SSNM improved farmers' rice yield by 0.2 t ha-1 in Ha Nam and by 0.34 t ha-1 in Ha Tay in the spring season. SSNM adopters appeared to have improved fertilizer management. SSNM increased net annual income by US$57 ha-1 in Ha Tay and by $78 ha-1 in Ha Nam. Simple projections for the wide application of SSNM throughout the RRD indicate potential annual gains of 228,000 tons of additional unmilled rice. Based on frontier production functions, adopters achieved a slightly higher index of technical efficiency in rice production. SSNM improved farmers' knowledge, attitudes, and skills in rice farming.