Preliminary Assessment of Rice Production in Coastal Part of Red River Delta Surrounding Xuan Thuy National Park, Vietnam, for Improving Resilience

Rice production in Giao Thuy district surrounding Xuan Thuy National Park at the estuary of Red River, Vietnam, was assessed by local rice statistics (1990-2012), historical climate (1961-2010) and salinity (2003-2012) recordings, farmer interviews, and on-farm yield and salinity trials, in order to clarify (1) vulnerability and resilience to climate hazards and seawater intrusion and (2) differences in rice production in buffer zone of Xuan Thuy National Park as compared with the outer zone. Intensive double rice cropping with small land size characterized the target site. Historical yield rapidly increased from the 1990s particularly for spring rice. Incidences of flood and pest seriously reduced yield of summer rice in some years (i.e., 2005, 2009), together with numerous various climatic damages perceived by farmers. Mean maximum air temperature has increased by 0.3 degrees C per decade, while its direct effects on rice yield were not conspicuous. Seawater intruded to longer distance toward upstream from the estuary: salinity became high at the intake gates nearby sea (i.e., 2.1% at Con Nhat) which have been replaced with the new upstream intake gate. The salt concentration of standing water in the 28 selected paddy fields was generally maintained lower. Rice yield in the fields nearby the river/coast dyke was lower than those far from the dyke. Inputs of inorganic fertilizers and pesticides were equally high in buffer zone of Xuan Thuy National Park as in the outer zone. Possible strategies to improve resilience of rice production in Giao Thuy were discussed.