Comparative study of water requirements and water footprints of fibre crops hemp (Cannabis sativa) and cotton (Gossypium hirsutum L.)

Water is a valuable and limited resource, which is becoming increasingly under pressure due to the impacts of climate change and over utilization by the agricultural industry. Cotton is the predominant natural fibre utilized within textiles and is a highly water-intensive crop, thereby contributing to the negative environmental impacts of water use in agriculture, such as depletion of water from ecosystems and other uses, land degradation, and dissemination of pollutants. Accordingly, there is significant interest in establishing alternative natural fibre sources, which have lower water requirements. Cannabis sativa (hemp) fibre is becoming an increasingly popular fibre alternative and is purported to require less water during its cultivation. Accordingly, herein data was compared across 28 prior published sources, which identified that hemp has a 38% lower crop water requirement (CWR), 60% lower water footprint (WF), 84% lower crop irrigation requirement (CIR), and 91% lower irrigated water footprint (IRF) as compared to cotton. Therefore, these results support hemp as a water-efficient environmentally sustainable alternative to cotton for fibre cultivation.