Arundo micrantha Lam. as an alternative to Arundo donax L. as energy crop in saline soils irrigated with treated urban wastewaters.
This study reports the first data collected for the perennial grass Arundo micrantha Lam. as a new energy crop. To determine the yield of biomass production of indigenous A. micrantha, we cultivated it in Pla de Sant Jordi (Mallorca, Spain) during the 2013-2016 growing seasons in marginal soils, irrigating it with treated urban wastewaters (TUWW). Arundo donax was cultivated in the same field conditions as a reference energy crop. Our results show that A. micrantha has a remarkable yield determined by a higher density of stems per area and a greater difference between the external and internal diameter. Furthermore, A. micrantha maintained most of its leaf mass in winter, while A. donax was defoliated by 80%. Comparing energy parameters, A. micrantha performed very similar to A. donax. However, A. micrantha produced more dry matter (67 t ha-1) than A. donax (54 t ha-1) after the third year of crop establishment, showing a possible subsequent positive trend. Our results point towards the indigenous Mediterranean A. micrantha as a promising energy crop that can be cultivated in marginal soils to provide biomass for energy production purposes, even outperforming the more invasive species.