Green Fodder Production and Water Use Efficiency of Some Forage Crops under Hydroponic Conditions

The objectives of this study were to evaluate five forage crops (alfalfa ( Medicago sativa ), barley ( Hordeum vulgare ), cowpea ( Vigna unguiculata ), sorghum ( Sorghum bicolor ), and wheat ( Triticum aestivum )) for green fodder production and water use efficiency under hydroponic conditions. The experiment has been conducted under temperature-controlled conditions (24 ± 1°C) and natural window illumination at growth room of Soilless Culture Laboratory, Arabian Gulf University, Manama, Bahrain. The results showed that green forage can be produced in 8 days from planting to harvest using hydroponic technique. Highest values for green fresh yields were recorded for the crops cowpea, barley, and alfalfa which gave 217, 200, and 194 tons/ha, respectively. However, only cowpea and barley crops gave the highest green dry yield, but not alfalfa. Barely crop used water more efficiently than the other four tested crops when produced about 654 kg fresh matter/m 3 water in comparison to 633, 585, 552, and 521 kg fresh matter/m 3 water for cowpea, sorghum, wheat, and alfalfa, respectively. No significant differences between barley and cowpea for water use efficiency were noted. It can be concluded from this study that barley crop can be considered the best choice for production of hydroponic green fodder with less water consumption.