外源氮对琼北不同类型土壤甲烷氧化能力的影响  

Effects of Exogenous Nitrogen on Methane Oxidation in Upland Soils of Different Types in Northern Hainan Island

作　　者：齐润杰 陈金霞[1] 但建国[1] 

机构地区：[1]海南大学环境与植物保护学院,海南海口570228

出　　处：《热带作物学报》2016年第8期1534-1539,共6页Chinese Journal of Tropical Crops

基　　金：国家自然科学基金项目(No.31260118)

摘　　要：氮输入是影响土壤氧化吸收大气甲烷（CH_4）的重要因子之一。通过对琼北5种旱地土壤进行室内培养实验,评价不同类型土壤对低浓度CH_4的吸收能力及其对硝态氮和不同浓度铵态氮的响应。结果表明：火山灰土、富铁土、雏形土、铁铝土和淋溶土的CH_4氧化速率分别为67.01,50.05,47.00,72.82和57.10 ng/（kg·h）。按100（mg/kg）N添加的硝态氮仅对铁铝土CH_4氧化有显著的抑制效果,而按此浓度添加的铵态氮能显著降低5种土壤的CH_4氧化速率。铵态氮对5种土壤CH_4氧化的抑制率与铵态氮添加量均呈极显著的线性正相关。每单位（mg/kg）铵态氮添加量对铁铝土CH_4氧化的抑制率最低,仅为其他4种土壤的53%~60%,这很可能跟铁铝土的高C/N和低N/P有关。因此,对这些土壤进行科学管理时,应根据土壤类型选用适宜的N肥类型,同时,还应提高土壤有机质含量,增施P肥,充分发挥土壤对大气CH_4的氧化潜力。Nitrogen inputs is one of the key factors affecting atmospheric methane consumption by soils. The soil samples collected from five litchi orchards in northern Hainan Island were incubated at 26℃ with gravimetric water content of 20% and an initial CH4 concentration of approximately 10 μL/L, in order to determine the effects of exogenous nitrogen on the methane oxidation in soils of different types. Average rate of CH4 oxidation without N inputs by Andosols, Ferrosols, Cambosols, Ferralsols and Luvisols was 67.01, 50.05, 47.00, 72.82 and 57.10 ng/（kg.h）, respectively. Addition of KNO3 at 100 mg N kg^-1 d.w.s did not result in significant inhibition of CH4 oxidation in the soils except Ferralsols due to the higher native nitrate content. In contrast, CH4 oxidation in all soils decreased significantly after adding （NH4）2SO4 at lOOmg N kg^-1 d.w.s. For all studied soils, percent inhibition by ammonia increased with the rate of ammonia application, which was fit well by linear regression. The slope for Ferralsols was only 0.10 and 53%-60% of those for other soils, indicating that the extent of ammonia inhibition of CH4 oxidation in Ferralsols was the smallest among the soils of the five types. Such response of CH4 oxidation in Ferralsols to added ammonia might be attributed to the highest C： N ratio and the lowest N： P ratio. Therefore, the correct selection of N fertilizers, improvement of organic matter status of soil, and application of P fertilizer were recommended for maintaining high CH4 oxidation rates for upland soils.

关 键 词：甲烷氧化 土壤类型 硝态氮 铵态氮 

分 类 号：Q938.13[生物学—微生物学]