外加可溶性碳氮对不同热量带土壤N_2O排放的影响

Influence of Soluble Carbon and Nitrogen on N_2O Emission from Different Thermal Zones Soil

在室内条件下研究了外加可溶性碳、氮对不同热量带经长期施肥的3种农田土壤:黑土、潮褐土和红壤N2O排放的影响。结果表明,在单施氮肥和可溶性碳配施氮条件下,不同热量带土壤N2O排放量从高到低分别为潮褐土(0.868、3.07μg.g-1),红壤(0.511、0.731μg.g-1),黑土(0.221、0.294μg.g-1),且添加可溶性碳显著促进了土壤N2O排放量。在黑土、潮褐土和红壤长期不同施肥土壤中,单施氮肥和可溶性碳配施氮后N2O排放量均表现为化肥+有机肥土壤>化肥土壤>无肥土壤,且与无肥土壤相比,红壤的化肥土壤N2O排放量增加254%,潮褐土化肥土壤增加49.5%,黑土化肥土壤增加1.74%,说明在有效积温越高的土壤上长期施肥对土壤N2O损失的贡献越大。研究结果还表明,外加可溶性碳、氮后,潮褐土铵态氮含量的减少幅度和硝态氮含量的增加幅度均显著高于黑土和红壤,说明潮褐土中氮素损失潜能大。

A laboratory experiment was conducted to study the influence of soluble carbon and nitrogen on nitrous oxide emission from different thermal zones soil, such as black soil, red soil and cinnamon soil Results showed that the amount of N2O emission in cinnamon soil ranged from 0.868 to 3.07μg·g^-1, which in red soil from 0.511 to 0.731μg·g^-1 and from 0.221 to 0.294 μg·g^-1 in red soil applied with only nitrogen or nitrogen amended with soluble carbon. Moreover, soluble carbon increased N20 emission if it was amended with nitrogen. The amount of N20 emission was in an order of NPKOM 〉 NPK 〉 CK, regardless of soil types and experiment treatments. It showed that long-term fertilization increased N2O emission, and amounts of increase were 1.74%, 49.5%, 254% in black soil, cinnamon soil and red soil separately. In addition, the variances of NH4-N and NO3-N contents in cinnamon soil were larger than other soils, which suggested that cinnamon soil had high potential of nitrogen loss.