Effects of using wastewater as nutrient sources on soil chemical properties in peri‐urban agricultural systems

Abstract

Reusing domestic wastewater for irrigation and applying biosolids as a fertiliser in crop production are common practices in peri‐urban areas of Vietnam. This study investigates the effects of using domestic wastewater in field experiments on Fluvisols soils in peri‐urban areas of Hanoi and Nam Dinh cities. We compared long‐term (30‐50 years) wastewater‐irrigated rice‐dominated farming systems. Using wastewater for irrigation significantly affected pH, electrical conductivity (EC), exchangeable K and Na and reverse aqua regia‐digestible (Rev Aq Reg) copper (Cu), lead (Pb) and zinc (Zn) in the investigated areas compared with control plots irrigated using river water. There were no significant effects of wastewater irrigation on the NH4NO3‐extractable fraction of cadmium (Cd) and other trace metals, but the EDTA‐extractable fraction of Cu, Pb and Zn was significantly increased.