中文摘要：

为探讨甲硫氨基酸对亚热带红壤硝化作用和N2O排放的影响,选择福建省建瓯市万木林保护区的山地红壤为研究对象,在土壤饱和持水量（WHC）60%和90%的条件下,开展室内培养试验.试验分为对照（CK）、添加甲硫氨基酸（M）、甲硫氨基酸和硫酸铵（MA）、甲硫氨基酸和亚硝酸钠（MN）、甲硫氨基酸和葡萄糖（MC）5个处理.结果表明：与对照相比,M处理使土壤NH4^＋-N平均含量显著提高0.8%-61.3%,而NO3^--N含量显著降低13.2%-40.7%;60%WHC条件下,MC处理土壤NO2^--N含量高于M处理,MA、MN处理NO3^--N含量高于M处理,且MN处理高于MA处理,M处理于试验后期最低,表明甲硫氨基酸抑制了硝化作用的亚硝化过程.碳添加处理使甲硫氨基酸在一定程度上降低NH4^＋-N含量,抑制了土壤自养硝化,并且甲硫氨基酸和碳源共同作用下NO3^--N含量变化与土壤水分条件有关,在90%WHC条件下,碳加入后反硝化作用更明显;而NO3^--N含量降低不足以表明是异养硝化受到抑制所致.甲硫氨基酸在一定程度上促进土壤N2O的释放,90%WHC条件下较60%WHC条件下释放量更大,且葡萄糖添加的促进效果更明显.

英文摘要：

The objective of this study was to investigate the influence of L-methionine on nitrification and nitrous oxide emission in a red soil under laboratory incubation experiments. A subtropical broad-leaved forest soil sample was collected from Wanmulin natural reserve in Fujian Province,Southeast China. Five treatments were carried out with three replications,i. e.,control（ CK）,Lmethionine addition（ M）,L-methionine and NH4^＋-N addition（ MA）,L-methionine and NO2^--N addition（ MN）,L-methionine and glucose addition（ MC）. The soil moisture was maintained at60% WHC or 90% WHC. The results indicated that the soil NH4^＋-N content in the M treatment significantly increased by 0. 8%- 61. 3%,while the soil NO3^-- N content reduced by 13. 2%- 40. 7%compared with CK. Under 60% WHC condition,soil NO2^--N content in the MC treatment was higher than in the M treatment,soil NO3^--N content in the MA and MN treatments were greater than that in the M treatment,and greater in the MN treatment than in the MA treatment. The soil NO3^--N content was lowest in the M treatment after incubation. These results suggested that L-methionine could inhibit nitrosation process of autotrophic nitrification. To some extent,carbon addition as glucose with L-methionine decreased the NH4^＋-N content,inhibited the autotrophic nitrification and their effects were dependent on water level. Under 90% WHC condition,carbon addition improved denitrification more obviously,but the decrease of NO3^--N content was not sufficient to prove the inhibition of hetero-nitrification due to carbon addition in the presence of L-methionine. The nitrous oxide emission from soil was increased by L-methionine addition. Compared with 60% WHC condition,the nitrous oxide emission was higher under 90% WHC condition,and the promotion of L-methionine addition on N2 O was greater when glucose added.