Chloride Sources and Losses in Two Tile-Drained Agricultural Watersheds
Chloride Sources and Losses in Two Tile-Drained Agricultural Watersheds
复制标题
DOI：
10.2134/jeq2015.06.0302
复制
发表时间：
2016-01-01
影响因子：
2.4
通讯作者：
Salemme, Ronald K.
中科院分区：
文献类型：
--
作者：
David, Mark B.;Mitchell, Corey A.;Salemme, Ronald K.
氯化物是一种相对不活泼的植物营养素，长期以来一直被用作生物地球化学示踪剂，但当浓度高时，也可能是一种污染物，导致水生生物影响，通常来自用于道路除冰的岩盐应用。流域的氯化物输入通常来自大气沉降、道路用盐或农业肥料，尽管对大量肥料输入的农业流域的研究很少。我们使用了长期（21和17年）的氯化物水质数据中东部伊利诺伊州的两条河流，以更好地了解氯化物在两个农业流域（恩巴拉斯和Kaskaskia），前者与一个较大的城市土地利用和广泛的瓷砖排水。在我们的采样期间，平均氯化物浓度为23.7和20.9毫克L-1的恩巴拉斯河和Kaskaskia河，分别。在Embarras和Kaskaskia流域，氯化物的年通量分别为72.5和61.2千克/公顷/年。在这两个流域，肥料氯化物是主要的输入（类似于49公斤公顷（-1）年（-1）），道路盐可能是另一个主要来源（23.2和7.2公斤公顷（-1）年（-1）恩巴拉斯和Kaskaskia流域）。结合我们的监测数据与早期公布的数据恩巴拉斯河显示，在20世纪60年代和70年代，随着钾肥使用量的增加，氯化物浓度增加，钾肥投入量的变化滞后约2至6年，基于多元回归模型。在这些农业流域，河水氯化物响应相对较快的钾肥作为一个结果瓷砖排水。
Chloride is a relatively unreactive plant nutrient that has long been used as a biogeochemical tracer but also can be a pollutant causing aquatic biology impacts when concentrations are high, typically from rock salt applications used for deicing roads. Chloride inputs to watersheds are most often from atmospheric deposition, road salt, or agricultural fertilizer, although studies on agricultural watersheds with large fertilizer inputs are few. We used long-term (21 and 17 yr) chloride water quality data in two rivers of east-central Illinois to better understand chloride biogeochemistry in two agricultural watersheds (Embarras and Kaskaskia), the former with a larger urban land use and both with extensive tile drainage. During our sampling period, the average chloride concentration was 23.7 and 20.9 mg L-1 in the Embarras and Kaskaskia Rivers, respectively. Annual fluxes of chloride were 72.5 and 61.2 kg ha(-1) yr(-1) in the Embarras and Kaskaskia watersheds, respectively. In both watersheds, fertilizer chloride was the dominant input (similar to 49 kg ha(-1) yr(-1)), with road salt likely the other major source (23.2 and 7.2 kg ha(-1) yr(-1) for the Embarras and Kaskaskia watersheds, respectively). Combining our monitoring data with earlier published data on the Embarras River showed an increase in chloride concentrations as potash use increased in Illinois during the 1960s and 1970s with a lag of about 2 to 6 yr to changes in potash inputs based on a multiple-regression model. In these agricultural watersheds, riverine chloride responds relatively quickly to potash fertilization as a result of tile-drainage.