Water Footprint of Energy Crops under the Rain-Fed and Irrigated Cultivation in Eastern Thailand

Abstract

Under the current 15-year Renewable Energy Development Plan (REDP) of 2008-2022, Thailand’s Ministry of Energy promotes the production and use of ethanol to substitute fossil oil. Two major crops used to produce ethanol in Thailand are sugarcane and cassava. This research assesses the water footprint (WF) of sugarcane and cassava under the rain-fed and irrigated agriculture in the eastern provinces of the Kingdom. The data on crop evapotranspiration, use of fertilizer, and yield are required for the estimation of the water footprint in crop production, the approach of which is based on The Water Footprint Assessment Manual of Hoekstra et al. The results of this study show that the average WF’s of sugarcane in rain-fed and irrigated cultivation are respectively 171 m³/ton (89% green, 11% grey) and 162 m³/ton (83% green, 7% blue, 10% grey). For cassava, the average WF’s in rain-fed and irrigated agriculture are 387 m³/ton (85% green, 15% grey ) and 413 m³/ton (81% green, 5% blue, 14% grey), respectively. Rainfall is still a key factor in the cultivation of sugarcane and cassava taking into consideration the proportion of water use. The sugarcane yield in the rain-fed fields is lower than that in the irrigated fields, while the yield of cassava in both environments is similar. The findings not merely would be of use to stakeholders and policymakers for better water management but also could be used as basis data of sub-national water footprint for crop production.