农业活动对土壤甲烷汇的影响研究

Impact of agriculture on the soil sink for methane

耕作对土壤CH4 吸收有长期抑制作用并极大地降低了土壤CH4 汇的强度。施NH4+ N肥可抑制土壤CH4 氧化 ,而NO3- N肥则无此作用 ,NH4+ N肥对土壤CH4 氧化的抑制效应大于等N量粪肥。C/N值小且导致土壤酸化的作物残茬对CH4 氧化的抑制作用较大 ,生物废弃物堆肥对土壤CH4 氧化有暂时抑制作用。灌溉和施用杀虫剂可减少土壤CH4 吸收量 ,免耕、施NO3- N肥和有机肥是维持与增加农田土壤CH4 吸收量的有效措施。

Tillage can largely reduce the soil CH 4 sink becaus e of its long inhibition on soil CH 4 uptake. Ammonium can inhibit CH 4 oxidatio n in the soil but nitrate can not do that. The effect of ammonium inhibition on soil CH 4 oxidation is better than the manure with the same amount of nitrogen as ammonium. Crop residue that has small C/N ratio or can lead to soil acidifica tion has a large inhibition on soil CH 4 oxidation. Biowaste compost has a shor t-term inhibition on soil CH 4 oxidation. Irrigation and the use of pesticide c an decrease the soil CH 4 uptake. No-tillage,application of ammonium and organ ic fertilizer are the available measures to remain or increase the potential of CH 4 uptake in arable soil.