Assessment of irrigation situation and water requirement in perennial fruit crops in Dinh Quan district, Dong Nai province

Dinh Quan is a mountainous agricultural district in Dong Nai province, focusing on agricultural development. Estimating reference and current crop evapotranspiration, as well as irrigation water requirements, is an essential foundation for effective irrigation planning for some perennial fruit crops (mandarin, banana, and mango) to manage water resources in a reasonable and sustainable way. Applying the FAO Penman-Monteith equation combined with the CROPWAT model, reference crop evapotranspiration (ETo), current crop evapotranspiration (ETc), and irrigation water requirement (IWR) of some perennial fruit crops being cultivated mainly in Dinh Quan district (banana, mandarin, and mango) were estimated. The total amount of water required for irrigation in the year of mandarin, mango, and banana trees in the study area was determined to be 592.6 mm, 473.0 mm, and 976.4 mm, respectively, corresponding to 5,926 m3/ha, 4,730 m3/ha and 9,764 m3/ha. Based on this result, the annual irrigation water requirement of the study area was calculated to be around 46 million m3 for the cultivation of mango, banana, and mandarin, mainly in the dry season (accounting for more than 95%). With current farming practices and using water resources, if there are no effective management measures and solutions, it may lead to a shortage of water for future production, especially in the dry season.