Surface water phosphorus loading must be reduced to improve water quality and decrease harmful algal blooms. Many wetlands have a natural capacity to retain inorganic reactive PO₄³⁻ via soil sorption. However, soil PO₄³⁻ retention capacity is finite and may be limited by soil legacy phosphorus effects in agricultural and urban areas. This study evaluated soil PO₄³⁻ retention in soils from a wetland constructed on former agricultural land in the Lake Erie, Maumee River watershed targeted for nutrient load reduction. Soil PO₄³⁻ sorption isotherms were evaluated under cool (10 °C), warm (22°), aerobic, and anaerobic treatments to determine changes in PO₄³⁻ retention due to environmental conditions and estimate seasonal changes in PO₄³⁻ sorption. The soils displayed a strong capacity for PO₄³⁻ retention by sorption. However, results indicate that cooler temperatures and anaerobic conditions decreased PO₄³⁻ sorption and lowered retention rates at PO₄³⁻ concentrations observed in the region. Soil amendment experiments investigated opportunities to increase PO₄³⁻ retention because many soils display elevated phosphorus concentrations due to historic land use, limiting their ability to adsorb additional PO₄³⁻. Amendments increased PO₄³⁻ retention capacity compared to unamended soils in the presence of high PO₄³⁻ concentrations, suggesting soil PO₄³⁻ retention can be improved in areas where natural storage capacity has been exhausted. Results from this study can inform natural resources managers in the Laurentian Great Lakes and elsewhere when identifying potential nutrient reduction wetland locations and assist with developing operational guidelines to optimize PO₄³⁻ retention and water quality improvements using wetlands.

必须减少地表水磷负荷，以改善水质并减少有害藻华。许多湿地具有通过土壤吸附保留无机活性 PO ₄ ^3-的天然能力。然而，土壤 PO ₄ ^3-保留能力是有限的，并且可能受到农业和城市地区土壤遗留磷效应的限制。本研究评估了在伊利湖、莫米河流域的前农业用地上建造的湿地土壤中土壤 PO ₄ ^{3−的保留，目标是减少养分负荷。}在冷（10°C）、暖（22°）、好氧和厌氧处理下评估土壤 PO ₄ ^3-吸附等温线以确定 PO ₄ ^3-的变化因环境条件引起的滞留并估计 PO ₄ ^3-吸附的季节性变化。土壤通过吸附显示出很强的 PO ₄ ^{3-保留能力。}然而，结果表明，在该地区观察到的较低温度和厌氧条件降低了 PO ₄ ^{3-吸附并降低了 PO} ₄ ^3-浓度下的保留率。土壤改良实验研究了增加 PO ₄ ^3-保留的机会，因为许多土壤由于历史上的土地使用而显示出升高的磷浓度，限制了它们吸附额外 PO ₄ ^3-的能力。修订增加 PO ₄ ³⁻_{与高浓度 PO 4} ^3-存在的未改良土壤相比，保留能力表明在自然储存能力已经耗尽的地区，土壤 PO ₄ ^{3-保留可以得到改善。}这项研究的结果可以在确定潜在的营养减少湿地位置时为劳伦森大湖和其他地方的自然资源管理者提供信息，并协助制定操作指南以优化 PO ₄ ^3-保留和使用湿地改善水质。