ABSTRACT
Storage of water in underground dams is an alternative to fulfill water needs in rural areas, mainly for plant use. For the construction of these dams, materials available in the region may be used, like clay, masonry, concrete and plastic canvas of PVC. This work had the objective of analysing the technical and economical viability of an underground dam built in a private farm at Alexandria-RN, Brazil, using plastic canvas of polyethylene. It could be concluded that even in a dry season the water content available in the soil was enough to fulfil the water needs of the crops, making possible to cultivate them during the whole year. In these conditions, a significant increase in the yield of maize, beans and rice was achieved in comparison to previous years in the same soil and climatic conditions. The yield increase allowed the farmer to sell the surplus production to increase his family income and to complement the food supply of his livestock with crop residues.
Key words:
underground dam; water; polyethylene; subirrigation