Irrigation benefits for rainfed cassava cultivation regions in Vietnam based on LINTUL-Cassava model

Abstract

Globally, climate variability is expected to lead to an increase in temperature resulting in an increase in the water use requirement of various crops. The study was to evaluate the WUR of cassava crops across the rainfed cultivation regions (RCRs) of Phu Yen Province, Vietnam based on the LINTUL-Cassava model simulation under current condition and future climate of the RCP4.5 and RCP8.5 scenarios. The LINTUL-Cassava model was assessed with low errors (d = 0.86, R2 = 0.87, RMSE less than 15.0% and NRSME less than 5.0). Results revealed that the water use requirement of spring and summer crops decreased by approximately 10.8-19.0% and 40.2-51.2% correspond to timescales of 2011-2040, 2041-2070, and 2071-2099 of the RCP4.5 scenario while a significant uptrend up to 13.0% and 32.9% recorded for long term (2071-2099) of the RCP8.5 scenario. The study revealed that rainfed can be utilized effectively if the crop cultivation time (CCT) was fixed to adapt to the changed climate factors.