• 关键词：红壤  旱地土  碳源  氮素矿化  反硝化

• 基金项目：中央高校基本科研业务费专项资金（No.2662016PY098）

• 徐鹏
• 华中农业大学资源与环境学院, 武汉 430070

• 邬磊
• 华中农业大学资源与环境学院, 武汉 430070

• 胡金丽
• 华中农业大学资源与环境学院, 武汉 430070

• 蒋梦蝶
• 华中农业大学资源与环境学院, 武汉 430070

• 赵劲松
• 华中农业大学资源与环境学院, 武汉 430070

• 胡荣桂
• 1. 华中农业大学资源与环境学院, 武汉 430070;2. 华中农业大学环境生态中心, 武汉 430070

• 摘要：为进一步理解红壤旱地土壤中碳源与土壤氮养分之间的耦合作用机制，以华中地区典型红壤旱地土壤为研究对象，运用静态培养法，设置室内培养试验，研究了添加葡萄糖、乙酸、草酸3种碳源对红壤旱地土壤中氮素矿化及反硝化的影响.结果表明，在25℃好氧培养下，不同碳源的添加对土壤氮素转化的影响具有较大差异.具体表现为：与对照处理（CK）相比，添加葡萄糖在整个培养期间内显著地促进了土壤可溶性有机氮（DON）含量的减少（p<0.01），在培养第1 d，添加葡萄糖显著地促进了氧化亚氮（N₂O）的排放、硝态氮（NO₃^--N）含量的减少（p<0.01）；添加乙酸也显著促进了上述过程（p<0.05），但促进作用没有葡萄糖强烈；而添加草酸对上述过程的促进不显著.30 d培养结束后，葡萄糖、乙酸、草酸3种处理的DON含量分别为14.84、19.46和23.47 mg·kg^-1，比CK处理（24.20 mg·kg^-1）分别减少了38.68%、19.59%、3.02%；葡萄糖、乙酸、草酸3种处理的NO₃^--N含量分别为8.77、13.89和20.42 mg·kg^-1，比CK处理（17.23 mg·kg^-1）分别减少了49.10%、19.38%和增加了18.51%.研究表明，碳源的可利用性是促进土壤氮素矿化和反硝化的关键因素.

• Abstract：In order to understand the coupling mechanism between the soil carbon and nitrogen in red upland soil,the effects of three kinds of carbon sources(glucose,acetic acid,oxalic acid) additions on the nitrogen mineralization and denitrification in red upland soil in central China area were investigated by a typical static incubation experiment carried out in the laboratory under 25℃ for 30 days.The results showed that the different carbon sources had diverse effects on nitrogen mineralization and denitrification of upland soil.Compared to the control treatment (CK),addition of glucose (Glu) significantly accelerated the decrease of soil dissolved organic nitrogen (DON) content and Glu significantly accelerated nitrous oxide (N₂O) emission and reduced nitrate nitrogen (NO₃^--N) content in the first one day of incubation.Addition of ace acid (Ace) also significantly promoted the processes above (p < 0.05) but faded next to Glu and there was no significant effect on the processes above after addition of oxalic acid (Oxa).After 30 days,the DON content of Glu,Ace and Oxa treatments were 14.84,19.46 and 23.47 mg·kg^-1,decreased by 38.68%,19.59% and 3.02% than that of CK treatment (24.20 mg·kg^-1),respectively; the NO₃^--N content of Glu,Ace,Oxa treatments were 8.77,13.89 and 20.42 mg·kg^-1,decreased by 49.10%,19.38% and increased 18.51% than that of CK treatment (17.23 mg·kg^-1),respectively.The research results showed that the availability of carbon sources is a key factor of accelerating the mineralization and denitrification of soil nitrogen.

• Key words：red soil  upland soil  carbon sources  nitrogen mineralization  denitrification

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