干湿交替对水钠锰矿促进黄棕壤性水稻土N2O释放效应的影响

Reduced Promoting Effect of Birnessite on N2O Emissions from Yellow-Brown Paddy Soil under Alternating Wet and Dry Conditions

    摘要
  • 摘要:
      目的  水稻土中锰氧化物的氧化还原状态可随土壤水分干湿交替而变化，影响土壤氮素循环，进而影响氧化亚氮（N2O）的排放。以土壤水分条件和水钠锰矿（0.1%，w/w）对土壤N2O释放的影响为切入点，探究干湿交替下水钠锰矿影响土壤N2O释放的机制。
      方法  以黄棕壤性水稻土为对象，设置不同水分条件和水钠锰矿（0.1%，w/w）进行微宇宙培养试验，探究土壤水分和水钠锰矿对土壤N2O释放的影响。
      结果  培养14 d内，土壤水分在60%和100%田间持水量恒定条件下水钠锰矿显著促进了土壤N2O累计释放量，增幅分别为11.3%和25.3%；但土壤水分在干湿交替（100% ~ 60%田间持水量）条件下水钠锰矿对土壤N2O累计释放量影响不显著。水钠锰矿显著提高了恒定土壤水分条件下亚硝酸还原酶（nirK）/氧化亚氮还原酶（nosZ）基因拷贝数比；但水钠锰矿显著降低了土壤水分干湿交替条件的nirK/nosZ基因拷贝数比。
      结论  土壤水分在干湿交替条件下不添加水钠锰矿处理和恒定条件下（60%和100%田间持水量）添加水钠锰矿处理分别促进黄棕壤性水稻土N2O的释放，但干湿交替条件下降低了水钠锰矿对土壤N2O释放的促进效应。土壤水分条件比水钠锰矿对黄棕壤性水稻土N2O释放的影响更大。

     

    Abstract:
      Objective  The redox state of birnessite in paddy soil can change with the soil wet-dry alternation, which affects the soil nitrogen cycle and then affects the emission of greenhouse gas nitrous oxide (N2O). The soil moisture conditions and the effect of birnessite (0.1%, w/w) on soil N2O emissions were taken as the breakthrough point to explore the mechanism of birnessite affecting soil N2O emissions under the alternation of wet and dry conditions.
      Method  In this study, the yellow-brown paddy soil was used as the object, and the microcosm culture experiment was carried out by applying birnessite (0.1% w/w) and using different water conditions to explore its effect on N2O emissions.
      Result  Within 14 days of culture, birnessite deeply promoted the cumulative N2O emissions under constant water conditions (60% and 100% field maximum water holding capacity treatments), with an increase of 11.3% and 25.3%. However, the effect of birnessite on the cumulative N2O emissions under the alternating of wet and dry conditions (100%-60% soil maximum water holding capacity) was not significant. Birnessite significantly increased the nitrite reductase (nirK)/nitrous oxide reductase (nosZ) gene copy ratio under constant water conditions. However, birnessite significantly decreased the ratio of nirK/nosZ under alternating wet and dry moisture conditions.
      Conclusion  The alternation of wet and dry conditions (100%-60% soil maximum water holding capacity) without birnessite or birnessite under constant water conditions can promote the release of N2O emissions from the yellow-brown paddy soil, but the alternation of wet and dry conditions (60% and 100% field maximum water holding capacity treatments) can reduce promoting effect of birnessite on N2O emissions. The effect of water conditions on N2O emissions from yellow-brown paddy soil is greater than birnessite.

     

    • HTML全文
    • 参考文献(33)
    • 相关文章
    • 施引文献
  • 资源附件(0)

/

返回文章
返回