Reclaimed Water Irrigation Effect on Agricultural Soil and Maize (Zea mays L.) in Northern China

Abstract

The concentration, spatial distribution, and source of trace metals (As, Cd, Cu, Cr, Pb, and Zn) are investigated in agricultural soils and maize (Zea mays L.) subjected to two distinct types of irrigation water in Northern China. The results indicate that the concentration of trace metals in soils irrigated for approximately 30 years with reclaimed water exhibit only minor differences in comparison to that irrigated with groundwater. However, the use of reclaimed water appear to result in higher concentrations of As and Cu in the agricultural soils. Geo‐statistical and principal component analyses suggest that Cr has a lithogenic origin and Cd, Pb, and Zn are mainly influenced by other human activities (e.g., vehicle emissions in case of Pb). With regards to maize, no significant differences in metal concentrations are observed in the grains. The highest concentrations of Cd are measured in the roots, whereas elevated concentrations of Cr and Pb are found in the leaves. Cu and Zn, as necessary elements for plant growth, have higher concentrations in grains compared to the other trace metals. The observed increase of Cu and As concentrations in soils and the concentration of Pb from both areas in grains of maize exceed the safety level, indicating that continued monitoring is required to insure food safety and sustainable crop production.