Soil subsidence of peatlands occurs worldwide due to drainage. The Everglades Agricultural Area (EAA), located in South Florida, has been drained for agriculture since 1914, with subsidence resulting in shallow soils in certain areas. The purpose of this study is to determine the impact of water management strategies on soil oxidation and N release as affected by differences in proximity to the bedrock. Oxidation rates (CO₂ efflux), as well as CH₄ and N₂O emissions, were measured in lysimeters filled with shallow and deep peat subjected to four water treatments. Additionally, NO₃–N, NH₄–N, soluble organic N, and dissolved organic C were measured in leachate obtained from the collected soils. Average annual emissions from constantly drained soils were 298 g CO₂–C m^–2 yr^–1, with most of the oxidation taking place between June and October. Short flood cycles increased annual oxidation rates compared with constantly drained soils, which had the second highest oxidation rate. Constantly flooded soils had the lowest annual oxidation rates, followed by summer flooded soils. Total N lost in leachate was highest for constantly drained soils, with NO₃ being the dominant form. The deep soils had higher losses of soluble N and C, whereas NO₃ losses from shallow soils were higher. Soil oxidation rates did not differ depending on proximity to the bedrock. We conclude that strategies that avoid short flooding cycles and include crop rotations that allow flooding during summer can reduce oxidation and N losses in leachate from EAA peats.

中文翻译：

---

水分管理对排水泥炭土壤中土壤氧化、温室气体排放和氮淋失的影响

由于排水，泥炭地的土壤沉降在世界范围内发生。位于佛罗里达州南部的大沼泽地农业区 (EAA) 自 1914 年以来一直为农业排水，沉降导致某些地区的土壤变浅。本研究的目的是确定水管理策略对土壤氧化和氮释放的影响，因为靠近基岩的差异会影响土壤。氧化率（CO ₂流出）以及CH ₄和N ₂ O 排放是在充满浅层和深层泥炭并经过四次水处理的蒸渗仪中测量的。此外，NO ₃ –N、NH ₄-N、可溶性有机氮和溶解有机碳在从收集的土壤中获得的渗滤液中进行测量。持续排水的土壤年平均排放量为 298 g CO ₂ –C m ^–2 yr ^–1，大部分氧化发生在 6 月和 10 月之间。与持续排水的土壤相比，短洪水周期增加了年氧化率，后者具有第二高的氧化率。经常淹水的土壤年氧化率最低，其次是夏季淹水的土壤。对于不断排水的土壤，渗滤液中的总氮损失最高，其中 NO ₃是主要形式。深层土壤的可溶性 N 和 C 损失较高，而 NO ₃浅层土壤的损失更高。土壤氧化率不会因与基岩的接近程度而异。我们得出的结论是，避免短期洪水周期并包括允许夏季洪水的作物轮作的策略可以减少 EAA 泥炭渗滤液中的氧化和氮损失。