Comparing Energy Indices and Water Productivity of Forage Production in Hydroponic and Conventional Conditions

Recent drought phenomenon in Iran has limited feed supplying for livestock enterprises. In this situation, forage fodder production in hydroponic condition could be a reasonable solution to overcome the water resources limitations in forage production process; however, all aspects of this system should be investigated prior to using it. In this research, these four treatments of forage production: hydroponic barley forage, conventional corn forage, conventional irrigated barley, and conventional alfalfa forage,  were compared from the point of view of water productivity and energy indices, in the form of a completely randomized experimental design with 12 replications in Niriz, Fars Province, south of Iran. Results showed that hydroponic barley forage and conventional method of producing barley had the maximum yield (1605052 kg/ha per year) and the minimum yield (6235 kg/ha per year) respectively. The highest water productivity (65.3 kg/m3) and the lowest water productivity (0.64 kg/m3) were obtained from hydroponic barley forage and the conventional method of producing alfalfa , respectively. Results also indicated that the conventional corn forage had the highest energy ratio, net energy gain, and energy productivity (1.88, 125844 MJ/ha, and 0.281 kg/MJ); the lowest amounts of energy indices (0.65, -15252661 MJ/ha, and 0.037 kg/MJ) belonged to the hydroponic barley forage. Conclusions showed that producing barley fodder in hydroponic condition could be a proper solution for supplying adequate forage for livestock in semi-arid climate condition of Niriz twonship,  provided that some amendments could be made in this  method of fodder producing system to reduce energy consumption and to enhance energy productivity.