Homayoon Raoufi, Jamily Abdul Saleem
ABSTRACT. Water crises in agricultural production are a serious issue in water-limited ecosystems and farming regions. This study was conducted to estimate crop water requirements, crop irrigation requirements, and irrigation scheduling under climate change in Central Afghanistan using CROPWAT8.0 software. The climatic variables were acquired from local organisations and the general circulation model (GCM) (1990–2020). The temperature and rainfall patterns were evaluated under three scenarios (RCP2.6, 4.5, and 8.5) from 2025 to 2100. CROPWAT8.0 was used to assess reference evapotranspiration, crop water requirements, crop irrigation requirements, and irrigation scheduling based on predicted meteorological conditions under different scenarios. The crop water requirements under RCP2.6, 4.5, and 8.5 increased by 9.74, 9.99, and 10.28 mm/day, respectively, compared to the baseline at 9.07 mm/day. Moreover, crop irrigation requirements would increase by 92.5 (18.46%), 109.7 (21.88%), and 100.7 mm/dec (20.09%) under RCP2.6, 4.5, and 8.5, respectively, compared to the baseline at 62.65 mm/dec. Furthermore, the results showed that wheat needs 3 irrigations in the baseline scenario, while it would need 4 irrigations for future scenarios due to an increase in crop irrigation requirements. The results of this study will be useful for agricultural practices and management.
Keywords: Afghanistan; irrigation scheduling; precipitation; scenarios; temperature.
