Dynamics of Eucalyptus and Sorghum biomass growth and nitrogen assessment at a Saharan sandy soil irrigated with treated wastewater

The study outlines the dynamics of Eucalyptus and Sorghum biomass under treated wastewater (TWW) irrigation in the Algerian Sahara to encourage water recycling and green biomass production regarding the freshwater (FW) shortage and plant cover rarity. Eucalyptus samples were taken at 03 different ages and 03 distinct layers. Sorghum samples were conducted from 2018 to 2020. The results proved a significant growth in Eucalyptus branch biomass and total biomass carbon of Eucalyptus branches in the layers 0–1 m and 2–4 m at 3 and 7 years old trees due to TWW irrigation. Eucalyptus aboveground biomass increased more with FW irrigation (mean values were 204.56 kg and 364.30 kg) compared to TWW irrigation (mean values were 126.64 kg and 222.56 kg) for 7 and 10 years old trees, respectively, across the ascending tree ages. Total nitrogen in Eucalyptus leaves was positively affected by TWW in the layers 2–4 m at 7 years old trees, with mean values of 3.10%. For Sorghum plants, TWW had a significant positive impact on the aboveground biomass, measuring 1.08 kg/m2 in autumn and 1.13 kg/m2 in spring, likewise on the total carbon biomass and nitrogen content. TWW irrigation can be an option for biomass growth for the studied vegetation in deserts.