Changing Agrometeorological Conditions for Maize (<i>Zea mays</i> L.) Under the Subtropical Climate of Northern Vietnam

Maize is an important food and feed crop for smallholder farmers in Vietnam and is affected by changing growing and crop management conditions under ongoing climate change posing potential production risks in the future. This study analyses future maize growing conditions in Northern Vietnam based on seven main agrometeorological indicators by applying the agrometeorological indicator software (AGRICLIM) on climate projections based on one global circulation model with an embedded regional climate model for two emission pathways (RCP4.5 and RCP8.5) from 1951 towards 2100. The results were analyzed for four time slices in annual, seasonal, and monthly scales and reveal that the future agrometeorological conditions for three local main maize growing seasons (winter, spring, and forage maize season) in general become more extreme compared to current conditions. In particular, the calculated increase in heat stress days, heavy precipitation events, and drought stress days for maize show different trends for the specific maize growing seasons. For example, drought and heat stress conditions may occur more frequently during the spring and forage maize season while the risk for soil erosions and N-leaching may rise in the winter and forage maize season. These findings will support the development of adaptation options under more adverse weather conditions for maize growing systems in Northern Vietnam.