THE AIM of this investigation is to evaluate the nutritional quality and productivity of green barley sprouts and spent sprouts (roots and basal medium) cultivated on rice straw rather than using a conventional hydroponic system. To optimize the resulting products, barley was cultivated under a range of CO₂ concentrations and in the presence of up to three different microbial inoculants. Barley sprouts both treated with 800ppm CO₂ and grown on rice straw in the presence of a consortium of Azotobacter chroococcum, Bacillus megaterium and Pseudomonas fluorescens showed significantly greatest shoot length (16.4 and 15.33cm), shoot fresh weight (1315.03 and 1217.95g/m²) and dry weight (185.11 and 171.45g/m²) than sprouts subjected to the other treatments when harvested at the first and second cuts, respectively, beside the highest significant protein (21.79%) and lipid (2.14%) levels than sprouts subjected to the other treatments when harvested at the first cut. Spent sprouts subjected to the same treatment showed significantly highest protein (8.95%), and lipid (1.98%) levels, significantly lowest crude fiber (21.93%) and a lowest C/N ratio (31.8). The highest significant spent sprout yield (3302.1 g/m²) was obtained when sprouts were grown in the absence of inoculants and under ambient air conditions. This study demonstrates the possibility of increasing the productivity and nutritive value of barley sprouts by cultivating sprouts on rice straw via different microbial inoculants in combination with elevated CO₂. The sprouts produced using this unconventional cultivation method was termed dual bio-barley fodder.