Influence of rainfall and seasonal crop practices on nutrient and pesticide runoff from soybean dominated agricultural areas in Pampean streams, Argentina.
Influence of rainfall and seasonal crop practices on nutrient and pesticide runoff from soybean dominated agricultural areas in Pampean streams, Argentina.
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DOI：
10.1016/j.scitotenv.2021.147676
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发表时间：
2021-05
期刊：
影响因子：
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通讯作者：
V. Andrade;M. Gutierrez;L. Regaldo;A. Paira;M. Repetti;A. Gagneten
中科院分区：
文献类型：
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作者：
V. Andrade;M. Gutierrez;L. Regaldo;A. Paira;M. Repetti;A. Gagneten
由于气候变化，预计降雨量的空间变异性将会增加。这意味着阿根廷潘帕斯地区春季和夏季降雨量增加，这是农用化学品最大使用期，这可能导致地表水系统携带的农药和养分增加，因为降雨径流是扩散污染的主要途径之一。作物物候阶段也会影响农药和养分径流，因为每个阶段施用的农用化学品和土壤覆盖情况不同。在这项研究中，我们评估了降雨和季节性作物种植对阿根廷潘帕斯地区三条溪流水质（养分和农药浓度）的影响。在两个不同的作物生产季节（SCP1、SCP2）期间，在三次降雨事件之前和之后进行了五次采样活动，并对溪流和径流水的物理化学特征进行了分析。降雨事件发生后，溪流中的农药浓度立即普遍增加。水质也受到影响，观察到铵、可溶性活性磷 (SRP)、生物需氧量 (BOD) 和浊度的增加。作物物候阶段影响溪流中检测到的农药和养分类型和浓度。 SCP1期间，主要以大豆的化学休耕和播种以及玉米的营养生长和开花为特征，铵、SRP、BOD、浊度以及某些农药（例如异丙甲草胺）的效果明显高于SCP2（大豆和玉米播种的籽粒灌浆和营养生长）。径流水中检测到的农药浓度主要取决于农药的溶解度、溪流的侧坡以及河岸木本植被覆盖的百分比。获得的结果表明评估降雨和作物物候阶段对地表水动态以及农药和养分径流的影响对于环境监测具有相关性。
An increase in the spatial variability of rainfall is expected due to climate change. This implies increasing rainfall rates during spring and summer in the Pampas region, Argentina, period of maximum application of agrochemicals, which might cause an increase in pesticides and nutrients carried to surface water systems, as runoff by rainfall is one of the main pathways for diffuse pollution. The crops phenological stage can also affect pesticide and nutrient runoff since the applied agrochemicals and soil cover differ in each stage. In this study, we assessed the influence of rainfall and seasonal crop practices on water quality (nutrient and pesticide concentrations) in three streams in the Pampas region, Argentina. Five sampling campaigns were performed before and after three rainfall events during two different seasons of crop practices (SCP1, SCP2) and the physicochemical characteristics of the stream and runoff water were analyzed. The pesticide concentrations in the streams presented a general increase immediately after the rainfall event. Water quality was also affected, as an increase in ammonium, soluble reactive phosphorus (SRP), biological oxygen demand (BOD), and turbidity was observed. The crops phenological stage influenced pesticide and nutrient types and concentrations detected in the streams. During SCP1, mainly characterized by chemical fallow and sowing of soybean and vegetative growth and flowering of corn, ammonium, SRP, BOD, turbidity, and some pesticides, such as metolachlor, showed significantly higher results than those found in SCP2 (grain filling and vegetative growth of soybean and corn sowing). The pesticide concentrations detected in runoff water depended mostly on the pesticide solubility, the lateral slope of the streams, and the percentage of woody riparian vegetation cover. The results obtained show the relevance of assessing the influence of rainfall and crops phenological stages on the dynamics of surface water and on pesticide and nutrient runoff for environmental monitoring.