Water management in raised bed systems: a case study from the Chao Phraya delta, Thailand

Agricultural diversification is a major trend in Asian rice-based systems. In lowlands, however, soil and water conditions are mostly suitable for rice cultivation and the development of raised beds is often required to accommodate vegetables or fruit trees. Raised bed systems go together with specific techniques of water management, both at the polder level (between the plots and the canals) and at the plot level (bed irrigation). Details of this management in the Chao Phraya Delta are given for three different crops: mango, grapes and asparagus and differences are explained. The water balance over 1 year is specified, showing the impact of seepage and estimating water requirements. Water quality is shown to be a major issue. (C) 1999 Elsevier Science B.V, All rights reserved.