Variation of bioenergy efficiency of Arundo donax L. growing in northern and middle Egypt

Giant reed (Arundo donax L.) is a promising non-food crop for the production of lignocellulosic biomass and sustainable bioenergy due to its high growth rate, perennial nature, and adaptability to marginal lands. This study investigates the variability in key bioenergy-related traits, biomass, carbon content, carbon sequestration, and water use efficiency (WUE), across fifteen naturally occurring A. donax populations in northern and middle Egypt, and identifies the primary environmental factors driving this variation. We assessed plant functional traits and corresponding soil properties to determine optimal growth conditions. Our results demonstrate that soil available potassium was a major positive driver of bioenergy potential, showing significant positive correlations with plant biomass and carbon sequestration capacity. Conversely, excessive soil available nitrogen was associated with reduced biomass, indicating a potential inhibitory effect. The studied populations thrived in marginal, alkaline soils, suggesting that A. donax can be cultivated on degraded lands without competing with most food crops that prefer neutral pH. We recommend selecting high-performing breeds for cultivation on marginal lands in Egypt and similar Mediterranean regions, leveraging favorable environmental conditions to establish a low-cost, sustainable bioenergy feedstock supply.