Environmental and Social Change Program, The University of Winnipeg, Winnipeg, Manitoba, Canada; Department of Soil Science, The University of Manitoba, Winnipeg, Manitoba, Canada.
Department of Soil Science, The University of Manitoba, Winnipeg, Manitoba, Canada; Department of Environmental Studies and Sciences, The University of Winnipeg, Manitoba, Canada.
Environ Pollut. 2024 Sep 1;356:124333. doi: 10.1016/j.envpol.2024.124333. Epub 2024 Jun 5.
17β-estradiol is a naturally occurring estrogen, and livestock manure applied to agricultural fields is a major source to the environment. Liquid swine manure is widely applied to agricultural fields in the Canadian Prairies, a region where the majority of the annual runoff occurs during a brief snowmelt period over frozen soil. Transport of estrogens from manure amendments to soil during this important hydrological period is not well understood but is critical to mitigating the snowmelt-driven offsite transport of estrogens. This study quantified the concentration and load of 17β-estradiol in snowmelt from an agricultural field with a history of manure application under manure application methods: no manure applied, manure applied on the sub-surface, and on the surface, using a laboratory simulation study with flooded intact soil cores and a field study during snowmelt. A higher concentration of 17β-estradiol was in the laboratory simulation than in the field (mean laboratory pore water = 1.65 ± 1.2 μg/L; mean laboratory flood water = 0.488 ± 0.58 μg/L; and mean field snowmelt = 0.0619 ± 0.048 μg/L). There were no significant differences among manure application methods for 17β-estradiol concentration. Laboratory pore water concentrations significantly increased over time, corresponding with changes in pH. In contrast, there was no significant change in the field snowmelt concentrations of 17β-estradiol over time. However, for both laboratory simulation experiments and field-based snowmelt experiments, mean concentrations of 17β-estradiol were higher with subsurface than surface-applied manure, and the cumulative load of 17β-estradiol was significantly higher in the sub-surface than in surface applied. The mean cumulative load from the field study across all treatments (6.91 ± 3.7 ng/m) approximates the magnitude of 17β-estradiol that could be mobilized from manured fields. The sub-surface application of manure seems to increase the persistence of 17β-estradiol in soil, thus enhancing the potential loss to snowmelt runoff.
17β-雌二醇是一种天然存在的雌激素，而施用于农田的牲畜粪便则是环境中雌激素的主要来源。液态猪粪广泛应用于加拿大草原的农田，该地区大部分径流量是在冬季土壤冻结期间短暂的融雪期发生的。在这个重要的水文时期，粪肥改良剂中的雌激素向土壤中的迁移情况尚不清楚，但对于减轻融雪驱动的雌激素场外迁移至关重要。本研究通过实验室模拟试验（使用淹没的完整土芯）和融雪期田间试验，量化了一个有粪肥施用史的农田中 17β-雌二醇在融雪中的浓度和负荷，该农田的粪肥施用方式有：不施粪肥、地表施粪肥和地下施粪肥。实验室模拟试验中 17β-雌二醇的浓度高于田间（实验室模拟试验中土壤孔隙水的平均浓度为 1.65±1.2μg/L；实验室模拟试验中洪水水的平均浓度为 0.488±0.58μg/L；田间融雪的平均浓度为 0.0619±0.048μg/L）。三种粪肥施用方式对 17β-雌二醇浓度均无显著影响。实验室土壤孔隙水浓度随时间显著增加，与 pH 值的变化相对应。相比之下，田间融雪期间 17β-雌二醇浓度随时间无显著变化。然而，对于实验室模拟试验和基于田间的融雪试验，地下施用粪肥的 17β-雌二醇平均浓度高于地表施用，地下施用的 17β-雌二醇累积负荷也明显高于地表施用。所有处理的田间研究的平均累积负荷（6.91±3.7ng/m）接近可从施肥农田中迁移的 17β-雌二醇的数量。粪肥的地下施用似乎增加了 17β-雌二醇在土壤中的持久性，从而增强了向融雪径流的潜在损失。
