Irrigation with treated wastewater in humid regions: Effects on Nitisols, sugarcane yield and quality

Treated wastewater (TWW) reuse for crop irrigation has been developing in recent decades areas hampered by severe water shortages. However, humid conditions, the agronomic impacts of supplementary are less and poorly documented. On island Réunion, we measured sugarcane yield quality on a Nitisol over 2 years providing 2600 mm TWW or (control) as supplement to 3500 rainfall. Meanwhile, with same TWW, (IW) rainfall inputs, monitored leachates soil under controlled conditions without plants. Sugarcane yield, Brix degree, fiber sucrose contents were similar between control plots each year. The leachate pH electrical conductivity at 60 cm depth showed marked differences modalities. Similarly, after constant increase chloride, sulfate, potassium sodium contents, breakthrough curves calcium magnesium, concentrations these elements modality stable from 12 pore volumes (PV), except which was 16 PV. At end experiment, hydraulic organic carbon did not show any significant change, while soils that had received higher overall than initial soil. dynamics major 65 consistent input variations exchangeable base experiment. mineral nitrogen accumulated profile there low leachate. quantities provided, uptake plants, competition adsorption leaching, pedoclimatic context, could therefore: (i) explain absence negative impact, (ii) highlight benefits environments requirements fertilize intensive crops. • Irrigation can meet fertilizer does affect compared fertilized irrigated control. have Nitisols environments.