Institute of Soil Science and Soil Conservation, Research Centre for BioSystems, Land Use and Nutrition (iFZ), Justus Liebig University Giessen, Heinrich-Buff-Ring 26, Giessen 35392, Germany; Environmental fate of chemicals and remediation (EnFaCRe) laboratory, Department of Environmental Management and Toxicology, University of Delta, Agbor, Nigeria.
Institute of Soil Science and Soil Conservation, Research Centre for BioSystems, Land Use and Nutrition (iFZ), Justus Liebig University Giessen, Heinrich-Buff-Ring 26, Giessen 35392, Germany.
Ecotoxicol Environ Saf. 2024 Sep 15;283:116794. doi: 10.1016/j.ecoenv.2024.116794. Epub 2024 Jul 29.
Recent pesticide use is alarmingly high and unregulated in several parts of the world. Pesticide fate in soil is controlled by sorption processes which affect the subsequent transport and chemical reactivity in the environment, as well as uptake by plants. Sorption processes are dependent on soil composition and properties, but these are beginning to be affected by global warming-linked factors leading to soil depletion. Thus, it is vital to decipher soils' response, especially in the sub-Sahara (SS), to the depletion of some inherent components in the presence of pesticides. This was ascertained by monitoring a model pesticide (atrazine) sorption and desorption on whole SS soil (WS), and the same soil whose organic matter (OMR) and iron oxides (IOR) were substantially depleted, as well as studying atrazine uptake from these soils by fast-growing vegetables. Organic matter depletion enhanced equilibrium in OMR. Sorption was enhanced at lower ambient pH, higher initial atrazine concentration, and higher temperature. Hysteresis was low resulting in high desorption. Overall, atrazine desorption of ≥65 % was observed; it was higher in OMR (≥95 %) since SOM enhanced hysteresis. Though sub-Saharan soils are rich in iron oxides, SOM played a significantly higher role in sorption than iron oxides in this soil. This result suggests a high potential for atrazine to leach into the aquifer in the sub-Saharan. Atrazine uptake experiment by waterleaf and spinach showed that it could be detected in soil after 63 d, and its presence significantly affected the growth of both vegetables especially in soils with depleted SOM and iron oxides, and at high (100 µg/kg) atrazine spiking. Spinach may be a higher atrazine accumulator than waterleaf. It may be concluded that waterleaf and spinach grown on atrazine-contaminated soils, especially on SOM/iron oxide-depleted soils, are likely to accumulate atrazine.
近年来，世界上有几个地区的农药使用量惊人地高且不受监管。农药在土壤中的命运受吸附过程控制，这些过程影响随后在环境中的迁移和化学反应活性，以及被植物吸收。吸附过程取决于土壤的组成和性质，但这些性质开始受到与全球变暖相关的因素的影响，这些因素导致土壤枯竭。因此，破译土壤对农药存在下某些固有成分枯竭的反应至关重要，特别是在撒哈拉以南非洲（SS）地区。这是通过监测模型农药（莠去津）在整个 SS 土壤（WS）上的吸附和解吸以及相同土壤中有机质（OMR）和氧化铁（IOR）大量枯竭的情况来确定的，以及研究这些土壤中莠去津被速生蔬菜吸收的情况。有机质枯竭增强了 OMR 的平衡。在较低的环境 pH 值、较高的初始莠去津浓度和较高的温度下，吸附增强。滞后现象较低，导致解吸较高。总的来说，观察到莠去津解吸率≥65%；在 OMR 中更高（≥95%），因为 SOM 增强了滞后现象。尽管撒哈拉以南非洲土壤富含氧化铁，但在这种土壤中，SOM 在吸附中比氧化铁发挥了更高的作用。这一结果表明，莠去津在撒哈拉以南地区有很高的潜在淋溶到含水层的风险。水蕹菜和菠菜的莠去津吸收实验表明，在 63 天后可以在土壤中检测到它，并且它的存在显著影响了两种蔬菜的生长，特别是在 SOM 和氧化铁枯竭的土壤中，以及在高（100µg/kg）莠去津喷洒的情况下。菠菜可能比水蕹菜更容易积累莠去津。可以得出结论，在莠去津污染土壤上种植的水蕹菜和菠菜，特别是在 SOM/氧化铁枯竭的土壤上，很可能会积累莠去津。
