The projection of rice production in Java Island to support Indonesia as the world food granary

The use of climate projections such as Cordex-SEA with crop simulation models can determine the projections of rice productivity in the future especially to meet the Indonesian vision as world food granary by 2045.This study aimed to 1) evaluate the projection of rice productivity and 2) compile a map of projected changes at the district level in Java Island in 2021-2035 and 2036-2050 for the RCP4.5 and RCP8.5 scenarios. The Agricultural Production System Simulator (APSIM) results based on the CSIROMK3.6 climate projection model for both scenarios in 2021-2035 showed that the impact of high productivity was high during the rainy season compared to the dry season. Districts with the increase of productivity indicate that these areas can be maintained or developed for rice crop. For the RCP4.5 scenario (rainy season) in the irrigated area, 41 districts out of 191 districts in Java Island had the class of up-high productivity changes. For the period of 2036 to 2050, there were fewer districts that had up-high productivity changes. The APSIM simulation results using HadGEM2 climate projections indicated more districts had decreased productivity in both year periods for both scenarios.