The effect of biochar addition on N2O and CO2 emissions from a sandy loam soil - The role of soil aeration
The effect of biochar addition on N2O and CO2 emissions from a sandy loam soil - The role of soil aeration
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DOI：
10.1016/j.soilbio.2012.03.017
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发表时间：
2012-08-01
影响因子：
9.7
通讯作者：
Whitaker, Jeanette
中科院分区：
文献类型：
--
作者：
Case, Sean D. C.;McNamara, Niall P.;Whitaker, Jeanette
生物炭作为一种减缓气候变化的策略具有巨大的潜力，因为它具有顽固的碳含量和观察到的抑制土壤温室气体排放的效果，如一氧化二氮（N2O）。生物炭改性后增加土壤透气性可能有助于这种抑制。以干土质量为2% （22 t ha(-1)）的硬木生物炭对芒地土壤核进行了改良。在3种不同温度（4℃、10℃和16℃）下培养126天，保持野外潮湿，一半进行周期性润湿。在10℃和16℃湿润48小时内，生物炭的累积N2O产量持续下降至少49%。我们得出结论，在与田间相关的温度范围内湿润4个月后，硬木生物炭抑制了土壤N2O排放。我们假设这是由于生物炭通过增加土壤的持水能力（WHC）而增加了相对高含水量下的土壤通气性，然而，这一假设被拒绝了。结果表明，5%和10%的生物炭添加量增加了土壤WHC。此外，10%的生物炭改进剂降低了土壤的容重。密封培养时，添加0- 10%干土重量的生物炭，并将其湿润至均匀的87% WHC （78% WFPS）。湿润后60 h内，1、2、5和10%生物炭处理的累积N2O产生量分别比无生物炭处理低19%、19%、73%和98%。我们得出结论，高水平的生物炭添加可能会改变土壤的物理性质，但生物炭添加对土壤通气性的增强对抑制沙壤土N2O排放的贡献很小。我们认为，添加生物炭后，微生物或物理固定土壤中的NO3-可能显著有助于抑制土壤N2O排放。(C) 2012 Elsevier Ltd.版权所有。
Biochar application to soil has significant potential as a climate change mitigation strategy, due to its recalcitrant C content and observed effect to suppress soil greenhouse gas emissions such as nitrous oxide (N2O). Increased soil aeration following biochar amendment may contribute to this suppression.Soil cores from a Miscanthus X. giganteus plantation were amended with hardwood biochar at a rate of 2% dry soil weight (22 t ha(-1)). The cores were incubated at three different temperatures (4,10 and 16 degrees C) for 126 days, maintained field moist and half subjected to periodic wetting events. Cumulative N2O production was consistently suppressed by at least 49% with biochar amendment within 48 h of wetting at 10 and 16 degrees C. We concluded that hardwood biochar suppressed soil N2O emissions following wetting at a range of field-relevant temperatures over four months. We hypothesised that this was due to biochar increasing soil aeration at relatively high moisture contents by increasing the water holding capacity (WHC) of the soil: however, this hypothesis was rejected.We found that 5% and 10% biochar amendment increased soil WHC. Also, 10% biochar amendment decreased bulk density of the soil. Sealed incubations were performed with biochar added at 0-10 % of dry soil weight and wetted to a uniform 87% WHC (78% WFPS). Cumulative N2O production within 60 h of wetting was 19, 19, 73 and 98% lower than the biochar-free control in the 1, 2, 5 and 10% biochar treatments respectively. We conclude that high levels of biochar amendment may change soil physical properties, but that the enhancement of soil aeration by biochar incorporation makes only a minimal contribution to the suppression of N2O emissions from a sandy loam soil. We suggest that microbial or physical immobilisation of NO3- in soil following biochar addition may significantly contribute to the suppression of soil N2O emissions. (C) 2012 Elsevier Ltd. All rights reserved.