Irrigation of energy crops with urban wastewater: Effects on biomass yields, soils and heating values

Exploitation of energy crops irrigated with non-conventional water resources on a large scale could decrease negative impacts from fossil fuel use, at the same time saving potable supplies and reducing disposal of polluting effluents in surface water, particularly in environments with water scarcity as Mediterranean basin. To this end, three energy crops (Typha latifolia, Arundo donax and Phragmites australis) were planted in experimental plots and irrigated over a 2-year period with the effluents of an urban wastewater depuration plant. Biomass and energy yields of the crops were evaluated; the effects on the main physical and chemical properties of soils (e.g. pH, EC, SOC, N, P) and leachate (pH, EC, COD) resulting from irrigation with wastewater were compared to those of irrigation with conventional water.