不同水分含量下黑土氧化亚氮排放差异

Difference of Nitrous Oxide Emission in Black Soil under Different Water Content

培育试验研究了40%WHC和80%WHC两种水分模式对铵态氮、硝态氮含量的变化以及N2O产排的影响.结果表明:在40%WHC低水分含量条件下,硝化反应占主导地位,通过硝化反应所产生的N2O含量相对较少,微生物呼吸作用较强;在80%WHC高水分含量条件下,土壤同时发生了强烈的硝化反应和反硝化反应,通过反硝化作用产生大量的N2O,发生了强烈的完全反硝化反应,微生物呼吸作用强于低水分含量条件.这些发现对于评价水分模式对黑土N2O产排的影响,土壤肥力和全球环境变化有着至关重要的意义.

Soil water content is the main factor affecting nitrogen transformation.Culture experiment was con-ducted to investigate ammonium,nitrate transformation and N2O production under two water contents of 40%WHC and 80%WHC.The results show that nitrification is dominant under the condition of 40%WHC with low water content,while the N2O content produced by nitrification is relatively small,and the microbial respi-ration is relatively strong.At 80%WHC,there were strong and simultaneous nitrification and denitrification reactions in the soil,a large amount of N2O is produced by denitrification.The microbial respiration is stron-ger than that under the condition of low water content.These findings are very important to evaluate the impact of water model on N2O production and emission,soil fertility and global climate change.