Department of Soil and Physical Sciences, PO Box 85084, Lincoln University, Lincoln 7647, New Zealand; Manaaki Whenua - Landcare Research, PO Box 69040, Lincoln 7640, New Zealand.
Manaaki Whenua - Landcare Research, PO Box 69040, Lincoln 7640, New Zealand.
Sci Total Environ. 2022 Dec 10;851(Pt 2):158274. doi: 10.1016/j.scitotenv.2022.158274. Epub 2022 Aug 27.
The addition of carbon (C) substrate often modifies the rate of soil organic matter (SOM) decomposition. This is known as the priming effect. Nitrous oxide (NO) emissions from soil are also linked to C substrate dynamics; however, the relationship between the priming effect and NO emissions from soil is not understood. This study aimed to investigate the effects of C and N substrate addition on the linkages between SOM priming and NO emissions. We applied C-labelled substrates (acetate, butyrate, glucose; 80 μg C g), with water as a control, and N-labelled N (300 μg N g soil, potassium nitrate) to three different soils, and, after 3 days, we measured the effects on the priming of SOM and sources of NO emission. Carbon substrate addition increased both CO- and SOM-derived NO emissions in the presence of exogenous N. Emissions of CO and NO from soils with added glucose (mean ± standard deviation, 0.73 ± 0.13 μmol m s and 21.4 ± 12.1 mg N m h) were higher (p < 0.05) than those from soils treated with acetate (0.64 ± 0.11 μmol m s and 10.9 ± 6.5 mg N m h) or butyrate (0.61 ± 0.11 μmol m s and 11.0 ± 6.6 mg N m h), respectively. Acetate addition induced a stronger (p < 0.05) priming effect on soil C (0.07 ± 0.09 μmol C m s) than that for glucose (0.02 ± 0.10 μmol C m s), while butyrate addition resulted in negative priming (-0.09 ± 0.05 μmol C m s). SOM-derived NO emissions were relatively low from soils with butyrate addition (1.4 ± 1.5 mg N m h) compared with acetate (2.9 ± 2.3 mg N m h) or glucose (9.2 ± 4.5 mg N m h). There was no clear relationship between the priming effect and SOM-derived NO emissions. The observed priming effect related to the potential electron donor supply of the C substrates was not observed. There is a need to further examine the role of soil priming in relation to soil NO emissions.
添加碳（C）底物通常会改变土壤有机质（SOM）分解的速率。这被称为激发效应。土壤中的氧化亚氮（NO）排放也与 C 底物动态有关；然而，激发效应与土壤中 NO 排放之间的关系尚不清楚。本研究旨在调查 C 和 N 底物添加对 SOM 激发与 NO 排放之间联系的影响。我们应用 C 标记的底物（醋酸盐、丁酸盐、葡萄糖；80 μg C g），以水为对照，并添加 N 标记的 N（300 μg N g 土壤，硝酸钾）到三种不同的土壤中，3 天后，我们测量了对 SOM 激发和 NO 排放源的影响。在添加外源 N 的情况下，C 底物的添加增加了 CO 和源自 SOM 的 NO 排放。添加葡萄糖的土壤（平均值 ± 标准差，0.73 ± 0.13 μmol m s 和 21.4 ± 12.1 mg N m h）的 CO 和 NO 排放量高于（p < 0.05）分别用醋酸盐（0.64 ± 0.11 μmol m s 和 10.9 ± 6.5 mg N m h）或丁酸盐（0.61 ± 0.11 μmol m s 和 11.0 ± 6.6 mg N m h）处理的土壤。与葡萄糖（0.02 ± 0.10 μmol C m s）相比，醋酸盐添加对土壤 C（0.07 ± 0.09 μmol C m s）的激发效应更强（p < 0.05），而丁酸盐添加则导致负激发（-0.09 ± 0.05 μmol C m s）。与醋酸盐（2.9 ± 2.3 mg N m h）或葡萄糖（9.2 ± 4.5 mg N m h）相比，添加丁酸盐的土壤中源自 SOM 的 NO 排放量相对较低（1.4 ± 1.5 mg N m h）。激发效应与源自 SOM 的 NO 排放之间没有明显的关系。没有观察到与 C 底物潜在电子供体供应有关的观察到的激发效应。需要进一步研究土壤激发与土壤 NO 排放之间的关系。
