【摘要】 介绍了不同量的¹⁵N标记的莴苣残体、废纸浆及土壤容重对反硝化及矿化作用的动态影响。试验结果表明:仅施加莴苣残体能在短期内（8d）增加土壤中反硝化作用,其N₂O释放最大量为对照的15倍;仅施用废纸浆在同期内不能增加N₂O释放量。与上述两种处理比较,二者混合施用可以刺激微生物活性和增加反硝化作用,但却比仅施莴苣残体的处理N₂O释放量小,说明同单纯施用莴苣残体相比混合施用可以增加氮的固定。CO₂释放量在不同处理中的全部107天中呈递减趋势,混合施用的处理中CO₂释放量每天均高于其它处理。在上述处理中,通过施加不同的压力（2,6,18kg）造成三种不同土壤容重。试验结果表明,70％的样本随容重增加N₂O与CO₂释放量增加,但差异显著性较弱或不明显。土壤容重的增加影响废纸浆的分解速率和NO₃^-与NH₄⁺浓度。更多还原

【Abstract】 Two laboratory incubation experiments aimed to study the denitrification and mineralisation influenced by different additives (15N labelled lettuce residue, paper wastes and mixture of both) and soil bulk densities were carried out by means of acetylene inhibition at the constant 15 C for 107 and 90 days, respectively. The results showed that the changes of N2O,CO2 emission rates,inorganic nitrogen (NO3-and NH4+) , total N and 15N abandance in the soils which were affected by adding lettuce residue, paper wastes and mixture of both were investigated. Soil denitrification rate increased after lettuce residue was added into soil for 8 days. The maximum rate of N2O emission was 15 times higher than that in soil without any additive. However, paper wastes did not increase N2O emission in the first 8 days compared with other treatments, mixed residue and paper wastes could promote soil mi-crobial activity, but N2O emission was lower than that in the soil with lettuce residue added and higher than that with paper wastes, indicating that mixture of residue and paper wastes was benefit to soil nitrogen immobilisation. CO2 emission in all the treatments were declined to the same level on the 107th day. In the treatment added mixed residues and paper wastes,the released CO2 quantities were higher than those in other treatments every day. Effect of different bulk density on N2O and CO2 emission were response to the change of bulk density, it seems that N2O and CO2 emission increased with bulk density. High bulk density could affect decomposition of paper wastes and NO3-, NH4+ concentration.更多还原