Effects of exogenous nitrogen on methane production from Deyeuxia angustifolia marsh in different plant growth phases
氮输入对三江湿地小叶章不同生长阶段土壤产生CH4能力的影响

CH4 production by D. angustifolia.over time was studied using indoor fresh soil cultivation under flooded soil conditions. The results indicated that the CH4 production rate showed significant volatility after nitrogen input at each growth phase. From the perspective of the mean CH4 production rate of the growing season (June 7~August 24), nitrogen input promoted CH4 production. The effect of different nitrogen input level on the CH4 production rate was obvious at different growth stages. In the first and second stages, moderate (6 g·m-2) nitrogen input promoted CH4 production, but excessive (12 g·m-2) nitrogen input suppressed CH4 production. However, nitrogen input always promoted CH4 production at the third and fourth stage. After nitrogen input, there were differences in dynamic relationships between soil microbial biomass C and N (MBC, MBN), soil basic respiration (BR), soil metabolic quotient (qCO2), soil induced respiration (SIR), ammonium nitrogen (NH+4-N), nitrate nitrogen (NO-3-N), plant biomass and CH4 production. Through correlative analysis, CH4 production was highly significantly related to qCO2 (p < 0.01), and significantly related to MBN,TOC and plant biomass (p<0.05).