A sustainable agricultural strategy integrating Cd-contaminated soils remediation and bioethanol production using sorghum cultivars

Cadmium (Cd) contaminant in soil can pollute crops and poison consumers higher in the food chain. Sorghum ( Sorghum bicolor (L.) Moench) is a promising bioenergy crop that can absorb and accumulate Cd from soil while generate renewable biomass resources for bioethanol or other valuable products, and limit waste production by rational utilization of all components. In this study, a sustainable agricultural strategy was presented and six sorghum cultivars grown under field conditions for the phytoremediation of Cd-contaminated agricultural soil were investigated with the goal of comparing their ability to accumulate Cd and their theoretical bioethanol yields (Cd concentration in the soil was 0.25 and 0.96 ppm). Striking differences were found in the Cd accumulation of these sorghum cultivars, and the result indicated that the Cd accumulation in stalks increased with maturity. The total absorbability of Cd ranged from 19.6 to 148 g/ha, and N6G60 sorghum showed the highest Cd accumulation with a concentration of 9.16 ppm in the stalk on a dry basis. The theoretical yield of bioethanol ranged from 5510 to 7510 L/ha. The overall performance of N6G60 and 15016 sorghums surpassed that of other sorghum cultivars because of their stronger capacities for Cd translocation and higher theoretical yields of bioethanol. Considering the experimental results, as well as the potential ethanol yield and growing situations of sorghums, 15016 sorghum was considered the cultivar showing the most promise for future applications.