Improving Water Use Efficiency in Semi-Arid Regions through Integrated Aquaculture/Agriculture

Two experiments were performed in the Bekaa plain in Lebanon to evaluate the feasibility of integrating aquaculture with established agriculture production in order to increase water productivity. Both experiments consisted of four plant management treatments: 1) Aquaculture effluent irrigation and no fertilizer; 2) aquaculture effluent irrigation and inorganic fertilizer; 3) well water irrigation and no fertilization; and 4) well water irrigation with inorganic fertilizer. In the first experiment, tilapia growth and radish production using aquaculture effluent were evaluated. All fish survived and grew, and radish production was improved by irrigating with aquaculture effluent. In the second experiment, maize (Zea mays) in large plots was irrigated with aquaculture effluent. Irrigation with effluent water improved maize production and improved soil nitrogen availability. In both experiments, fish production improved water value index and water use efficiency. Results suggest that aquaculture effluent can supplant inorganic fertilizers and could actually yield better crop production.