Organic soil amendments such as biochar and compost are thought to improve soil development, but it is unclear whether they affect nutrient leaching and greenhouse gas emissions. Using mesocosms, we investigated the effects of biochar and compost on nutrient leaching and greenhouse gas emissions across varying hydrologic regimes. Increased biochar decreased nutrient leaching and greenhouse gas emissions: the highest application rate (10% wt/wt) decreased cumulative phosphate leaching by 63% (SE 1.4), ammonium leaching by 65% (SE 0.8) and nitrate leaching by 92% (SE 0.3). Likewise, 10% biochar application decreased cumulative methane emissions by 92% (SE 3.7), carbon dioxide emissions by 48% (SE 7.0), and nitrous oxide emissions by 89% (SE 4.1). Biochar effects varied with hydrology for each greenhouse gas: stronger reductions in methane and nitrous oxide emissions were observed under waterlogged conditions, whereas stronger reductions in carbon dioxide emissions were observed at field capacity. In contrast with biochar, compost was the largest contributor to nutrient leaching and greenhouse gas emissions. These results suggest that biochar is most effective in soils with episodic flooding and drying rather than continuous flooding, and that compost should be avoided. We conclude that biochar can promote desirable functions simultaneously in restored wetland soils.

人们认为有机土壤改良剂（如生物炭和堆肥）可以改善土壤发育，但尚不清楚它们是否影响养分的淋失和温室气体的排放。我们使用中膜，研究了生物炭和堆肥在不同水文状况下对养分淋失和温室气体排放的影响。增加的生物炭减少了养分的淋失和温室气体的排放：最高的施用量（10％wt / wt）使累积的磷酸盐淋失减少了63％（SE 1.4），铵的淋溶减少了65％（SE 0.8），硝酸盐淋失了92％（SE 0.3）。同样，使用10％的生物炭可将累计甲烷排放量减少92％（SE 3.7），将二氧化碳排放量减少48％（SE 7.0），将一氧化二氮排放量减少89％（SE 4.1）。每种温室气体的生物炭效应随水文状况而变化：在淹水条件下，甲烷和一氧化二氮的排放量减少的幅度更大，而在田间生产能力下，二氧化碳的排放量减少幅度更大。与生物炭相反，堆肥是造成养分浸出和温室气体排放的最大因素。这些结果表明，生物炭在有间歇性驱油和干燥而不是连续驱油的土壤中最有效，应避免堆肥。我们得出的结论是，生物炭可以在恢复的湿地土壤中同时促进所需功能。这些结果表明，生物炭在有间歇性驱油和干燥而不是连续驱油的土壤中最有效，应避免堆肥。我们得出的结论是，生物炭可以在恢复的湿地土壤中同时促进所需功能。这些结果表明，生物炭在有间歇性驱油和干燥而不是连续驱油的土壤中最有效，应避免堆肥。我们得出的结论是，生物炭可以在恢复的湿地土壤中同时促进所需功能。