Productivity of energy sorghum irrigated with reclaimed wastewaters

The sustainability of biomass sorghum (Sorghum bicolor L. Moench.) in the Mediterranean environment is linked to the possibility of increasing crop productivity by using conventional clean water and wastewater irrigation. An experimental setup was arranged in Southern Italy during 2012 and 2013 seasons to determine the potential productivity of biomass sorghum irrigated with conventional water at different irrigation regimes (100 and 50% of calculated evapotranspiration) and different types of municipal wastewater. During the sorghum growing season, the crop development (biomass and leaf are index) and the soil water content were monitored for all irrigation treatments. The data obtained showed that the dry biomass of sorghum irrigated with the deficit treatment (17 t ha(-1)) was lower compared with conventionally irrigated sorghum. For both seasons and under full irrigated conditions, sorghum irrigated with wastewater produced on average more dry biomass (23 t ha(-1)) than the crop irrigated with conventional water (20.5 t ha(-1)), using the same irrigation volumes.