Trace Metals Accumulated in Pea Plant (Pisum sativum L.) as a Result of Irrigation with Wastewater

Abstract

Trace metals (TMs) that accumulated in different crops irrigated with untreated wastewater are public hazard problem. The present work aimed to evaluate the impact of utilizing untreated agricultural water in the irrigation system of the peas crop (Pisum sativum L.) until seed production on soil and plant characteristics. It also aimed to assess the effect of the applied wastewater on nutrients and TM contents in both soil and different plant parts (root, shoot ,and seed), and it extended to study TMs’ bioaccumulation and translocation ability of pea plant. Three composite soil and water samples were collected from the agricultural field (30°32’N and 31° 0′E) and agricultural wastewater effluent (30°34.5’N and 31°00.42′E) in Shebin El-Kom city used in irrigation of different crops. A pot experiment (each pot of 15 × 20 cm) was carried out in the botanic garden of Faculty of Science, Menoufia University, Egypt. TMs and nutrients were investigated for soil and plant samples. There was a significant increase in trace metal contents: cadmium (Cd), copper (Cu), chromium (Cr), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) for soil and pea plants as a result of irrigation with wastewater. Also, it caused a significant decrease in soil nitrogen (N), phosphorous (P), and Potassium (K) and plant (N, P, K, carbohydrates, and proteins) nutrients. A significant decline in pea growth parameters and the content of chlorophyll a and b and carotenoid in pea leaves were recorded. A high significant in TMs content for seeds (edible parts) was recorded (Cd = 75.6, Cu = 9.7, Cr = 29.8, Fe = 1123.6, Mn = 82.2, Ni = 26.8, Pb = 131.4 and Zn = 35.7 mg kg−1). The concentration of Cd, Cr, Fe, and Pb in seeds was in the phytotoxic range. Irrigation with wastewater shows a negative impact on the soil and plant characteristics. Also, it causes a significant decline in soil and plant nutrients. At the same time, it increases the concentration of TMs for soil and all plant organs. The concentration of Cd, Cr, Fe and Pb reached to the phytotoxic range in its seeds. Authors recommended that pea cultivated in soil and/or irrigated with untreated wastewater was not safe for human and animal consumption.