Pitton Bruno J L, Oki Lorence R, Evans Richard Y, Zhu-Barker Xia
Department of Plant Sciences, University of California, Davis, One Shields Ave., Davis, CA 95616, USA; Agriculture and Natural Resources, University of California, 11477 E Ave., Auburn, CA 95603, USA.
Department of Plant Sciences, University of California, Davis, One Shields Ave., Davis, CA 95616, USA.
Sci Total Environ. 2025 Aug 25;992:179899. doi: 10.1016/j.scitotenv.2025.179899. Epub 2025 Jun 24.
Nitrous oxide (NO) emissions from soilless growing substrates are significantly greater per production area than crops grown in mineral soil. To understand and identify the NO production pathways in soilless substrates, fir bark, peat, and peat:fir bark substrates were treated with labeled N fertilizers. The volumetric water content (VWC) of the soilless substrate was maintained near container capacity, and gas samples were collected every other day for 21 days and analyzed for N-NO content. Fir bark and peat:fir bark substrates had significantly greater total NO emissions than peat substrate when fertilized with NHNO. Denitrification was the main pathway of NO emissions from all substrates and it was more pronounced in the fir bark and peat:fir bark substrates. In the peat substrate, the contribution of ammonia oxidation to NO emissions started on day 11 and continued to increase until the end of the experiment, contributing to 6 % of the total NO emitted from this substrate. Overall, reducing denitrification-derived emissions from soilless substrates is critical to mitigate the impact of container-plant production on global warming. Future research should focus on developing strategies to reduce these emissions.
无土栽培基质每生产面积的一氧化二氮（NO）排放量比在矿质土壤中种植的作物要高得多。为了了解和确定无土基质中NO的产生途径，对杉木树皮、泥炭以及泥炭：杉木树皮基质施用了标记氮肥。将无土基质的体积含水量（VWC）维持在接近容器容量的水平，每隔一天采集气体样本，持续21天，并分析其中N-NO含量。当施用NHNO时，杉木树皮和泥炭：杉木树皮基质的总NO排放量显著高于泥炭基质。反硝化作用是所有基质中NO排放的主要途径，在杉木树皮和泥炭：杉木树皮基质中更为明显。在泥炭基质中，氨氧化对NO排放的贡献从第11天开始，并持续增加直至实验结束，占该基质总NO排放量的6%。总体而言，减少无土基质中反硝化作用产生的排放对于减轻容器植物生产对全球变暖的影响至关重要。未来的研究应侧重于制定减少这些排放的策略。
