Influence of biochars on flux of N2O and CO2 from Ferrosol.
Influence of biochars on flux of N2O and CO2 from Ferrosol.
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DOI：
10.1071/sr10004
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发表时间：
2010-10
期刊：
影响因子：
1.6
通讯作者：
L. Zwieten;S. Kimber;S. Morris;A. Downie;E. Berger;J. Rust;C. Scheer
中科院分区：
文献类型：
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作者：
L. Zwieten;S. Kimber;S. Morris;A. Downie;E. Berger;J. Rust;C. Scheer
绿色废物(GW)、家禽粪便(PL)、造纸厂废物(PS)和生物固体(BS)缓慢热解产生的生物炭可以减少酸性铁溶胶的N2O排放。未经处理的GW原料也出现了类似的减少。用生物炭或原料改良土壤，施用量分别为1%和5%。在初始培养后，以165公斤/公顷的尿素添加氮(N)。微宇宙再次孵化，然后被带到100%充满水的孔隙率，并在这个水分含量下再保持47天。淹水阶段的N2O排放量占总排放量的80%。对照土壤释放3165mgN2O-N/m2，占土壤速效N的15.1%。添加1%和5%GW原料的改良剂显著降低了排放量，分别为1470 mg N2O-N/m2和636 mg N2O-N/m2。这相当于施氮量的8.6%和3.8%。350°C下产生的GW生物炭在减少排放方面效果最差，1%和5%的改良剂分别为1625和1705 mg N2O-N/m2。添加5%BS生物炭的改良剂影响最大，在培养期间将排放量减少到518 mg N2O-N/m2，或施氮量的2.2%。用二氧化碳产生量衡量的代谢活性不能解释对照和改良剂之间N2O排放的差异，也不能解释生物炭改良剂土壤中NH4+或NO3-浓度的差异。使用GW原料后NH4+和NO3-的减少很可能是这一修正案减少N2O排放的原因。生物炭改良土壤中N2O排放量的减少归因于对N3-的吸附增加。由于曝气量和孔隙率的改善，反硝化和N2O排放水平较低，因此可能会出现小幅减少。或者，观察到pH的增加，这可以在土壤淹水过程中推动反硝化作用转化为氮素。
Biochars produced by slow pyrolysis of greenwaste (GW), poultry litter (PL), papermill waste (PS), and biosolids (BS) were shown to reduce N2O emissions from an acidic Ferrosol. Similar reductions were observed for the untreated GW feedstock. Soil was amended with biochar or feedstock giving application rates of 1 and 5%. Following an initial incubation, nitrogen (N) was added at 165 kg/ha as urea. Microcosms were again incubated before being brought to 100% water-filled porosity and held at this water content for a further 47 days. The flooding phase accounted for the majority (<80%) of total N2O emissions. The control soil released 3165 mg N2O-N/m2, or 15.1% of the available N as N2O. Amendment with 1 and 5% GW feedstock significantly reduced emissions to 1470 and 636 mg N2O-N/m2, respectively. This was equivalent to 8.6 and 3.8% of applied N. The GW biochar produced at 350°C was least effective in reducing emissions, resulting in 1625 and 1705 mg N2O-N/m2 for 1 and 5% amendments. Amendment with BS biochar at 5% had the greatest impact, reducing emissions to 518 mg N2O-N/m2, or 2.2% of the applied N over the incubation period. Metabolic activity as measured by CO2 production could not explain the differences in N2O emissions between controls and amendments, nor could NH4+ or NO3– concentrations in biochar-amended soils. A decrease in NH4+ and NO3– following GW feedstock application is likely to have been responsible for reducing N2O emissions from this amendment. Reduction in N2O emissions from the biochar-amended soils was attributed to increased adsorption of NO3–. Small reductions are possible due to improved aeration and porosity leading to lower levels of denitrification and N2O emissions. Alternatively, increased pH was observed, which can drive denitrification through to dinitrogen during soil flooding.