Meskelu Tsigereda, Senbeta Abate Feyissa, Keneni Yadessa Gonfa, Sime Getachew
Department of Biology Hawassa University Hawassa Ethiopia.
Center for Ethiopian Rift Valley Studies Hawassa University Hawassa Ethiopia.
Food Sci Nutr. 2024 Jul 25;12(10):7449-7460. doi: 10.1002/fsn3.4363. eCollection 2024 Oct.
The accumulation of heavy metals in soil and plant tissue is a serious concern since it impacts both soil quality and food safety. This study evaluated the accumulation of heavy metals and the food quality of lettuce as a result of the application of chemical fertilizer (CF) and bioslurry (BS). The treatments were CF (158 kg ha NPS and 200 kg ha urea), BS (5 ton ha), and control with no fertilizer, laid out in a randomized complete block design with three replications. Soil samples were analyzed for their physico-chemical characteristics. The concentrations of 10 heavy metals (As, Pb, Zn, Cd, Cu, Ni, Co, Fe, Mn, and Cr) in the agricultural soil, bioslurry, and lettuce tissue were determined. Both the BS and CF reduced the concentrations of most heavy metals in the agricultural soil, particularly As, Pb, and Cd. Only the mean concentration of Cd in the agricultural soils exceeded the threshold level set by WHO/FAO (2011) for agricultural soils. Similarly, the concentration of As, Pb, and Cd in lettuce tissue grown in BS-treated soils and the concentration of As in agricultural soils surpassed the limit set for vegetables. Given the toxicities of As, Cd, and Pb, as well as the effect on food safety, human health, and the environment, it is unsafe to cultivate lettuce using either the agricultural soil or BS in the study area.
土壤和植物组织中重金属的积累是一个严重问题，因为它会影响土壤质量和食品安全。本研究评估了施用化肥（CF）和生物泥浆（BS）后生菜中重金属的积累情况以及食品质量。处理方式包括CF（158千克/公顷氮磷钾和200千克/公顷尿素）、BS（5吨/公顷）以及不施肥的对照，采用随机完全区组设计，重复三次。对土壤样品进行了理化特性分析。测定了农业土壤、生物泥浆和生菜组织中10种重金属（砷、铅、锌、镉、铜、镍、钴、铁、锰和铬）的浓度。BS和CF都降低了农业土壤中大多数重金属的浓度，尤其是砷、铅和镉。只有农业土壤中镉的平均浓度超过了世界卫生组织/联合国粮食及农业组织（2011年）为农业土壤设定的阈值水平。同样，在BS处理土壤中生长的生菜组织中砷、铅和镉的浓度以及农业土壤中砷的浓度超过了蔬菜的限量标准。鉴于砷、镉和铅的毒性以及对食品安全、人类健康和环境的影响，在研究区域使用农业土壤或BS种植生菜是不安全的。
