Water management for rice cultivation in the dry zone of Sri Lanka

arroz asia asie cereales cereals clima climat climate climatic zones condiciones ambientales condition de milieu cropping patterns crops cultivos cultivos de grano drainage drenaje economic plants engineering environment environmental conditions environnement facteur de production grain crops hydraulic engineering irrigation land manejo del suelo medio ambiente mise en valeur du sol mode de culture plantas plante plante de culture plants production factors rice riego riz site factors soil management sri lanka terre terre humide tierras water management wetlands zone climatique zone semi-aride