Sustainable and effective irrigation through a new subsoil irrigation system (SIS)

Since scarcity of water is a major problem in semi-arid and arid areas of Spain and many other Mediterranean regions, water consumption in irrigated agriculture has to be reduced to a sustainable level that is also adapted to the environment. This goal can be reached by applying the highly effective and resource preserving techniques of micro-irrigation. In order to improve these techniques, a new subsurface irrigation system was developed by modification of conventional subsurface systems through the following innovative elements: a new design of the lateral hoses which prevents the penetration of roots into the external water outlets and the block up by soil particles; an impermeable polyethylene foil placed below the lateral pipes to prevent water loss through deep percolation especially in sandy substrates; a special installation equipment consisting of a V-shaped device which releases foil and pipe simultaneously into the soil without disturbing the natural soil profile. After the experience of several years of operation, these elements have proved to be highly effective. Compared to other irrigation methods, the high irrigation efficiency achieved by this system was outstanding. Minimum maintenance requirement and a long life span are additional positive characteristics of the system. The beneficial outcomes of this system give reason for an optimistic appraisal of the strategies involved towards sustainable irrigated agriculture. (C) 1999 Elsevier Science B.V. All rights reserved.