Nitrous oxide uptake in rewetted wetlands with contrasting soil organic carbon contents
Nitrous oxide uptake in rewetted wetlands with contrasting soil organic carbon contents
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DOI：
10.1016/j.soilbio.2016.06.009
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发表时间：
2016-09
影响因子：
9.7
通讯作者：
R. Ye;W. Horwath
中科院分区：
文献类型：
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作者：
R. Ye;W. Horwath
回湿排水泥炭地创造有利的条件，减少反硝化作用，但恢复泥炭地作为N2 O汇的潜力是很差的特点。我们监测N2 O排放量的再湿润泥炭地转化为稻田与一系列的土壤有机碳（SOC）（6%，11%和23%）在生长季节。在所有地点都反复观察到N2 O的负排放，在80 kg N ha−1的氮肥水平上不受影响。最高的消耗率为8.2吨CO2当量公顷-1yr-1，占排水泥炭土平均CO2排放量的32%。孔隙水N2 O浓度往往低于situN 2 O平衡浓度计算，表明大气N2 O扩散到孔隙水的限制。氧化还原电位与N_2O排放速率相关（r ~ 2 = 0.40，p < 0.01）。然而，相对较高的频率和幅度的负N2 O排放量主要观察期间的水绘制下来的水稻收获活动，特别是在该领域的最高SOC。这是可能的，减少水深排水减少了大气N2 O进入土壤的扩散障碍。总的来说，重新湿润的泥炭地作为大气N2 O汇的能力可能是显着的，似乎可以通过操纵水深管理。
Rewetting drained peatlands creates favorable reduced conditions for denitrification, but, the potential of restored peatlands to act as N2O sink is poorly characterized. We monitored N2O emissions in rewetted peatlands converted to rice paddies with a range of soil organic carbon (SOC) (6%, 11%, and 23%) during the growing season. Negative N2O emissions were repeatedly observed in all sites, which were not affected by nitrogen fertilization at 80 kg N ha−1. The highest consumption rates amounted to 8.2 tones CO2eq ha−1yr−1, 32% of the average CO2emissions from drained peat soils. Porewater N2O concentrations were frequently less than the calculatedin situN2O equilibrium concentrations, suggesting diffusional constraints on atmospheric N2O into pore water. Redox potentials were correlated to N2O emission rates (r2= 0.40,p< 0.01). However, relatively higher frequencies and magnitudes of negative N2O emissions were mostly observed during the period of water draw down for rice harvest activities, especially in the field with the highest SOC. It is likely that reducing water depth by drainage reduced the diffusional barrier for atmospheric N2O into the soil. In all, the capacity of rewetted peatlands to act as atmospheric N2O sinks can be significant and seemingly can be managed through manipulating water depths.