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(N_(2)O)的排放。以土壤水分条件和水钠锰矿(0.1%,w/w)对土壤N_(2)O释放的影响为切入点,探究干湿交替下水钠锰矿影响土壤N_(2)O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N_(2)O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N_(2)O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N_(2)O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N_(2)O的释放,但干湿交替条件下降低了水钠锰矿对土壤N_(2)O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N_(2)O释放的影响更大。
[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(N_(2)O).The soil moisture conditions and the effect of birnessite(0.1%,w/w)on soil N_(2)O emissions were taken as the breakthrough point to explore the mechanism of birnessite affecting soil N_(2)O 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 N_(2)O emissions.[Result]Within 14 days of culture,birnessite deeply promoted the cumulative N_(2)O 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 N_(2)O 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 N_(2)O emissions from the yellowbrown 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 N_(2)O emissions.The effect of water conditions on N_(2)O emissions from yellow-brown paddy soil is greater than birnessite.
作者
甘雪莲
郑恒
付庆灵
胡红青
朱俊
GAN Xue-lian;ZHENG Heng;FU Qing-ling;HU Hong-qing;ZHU Jun(College of Resources and Environment,Huazhong Agricultural University,Wuhan 430070,China)
出处
《土壤通报》
CAS
CSCD
北大核心
2023年第4期872-880,共9页
Chinese Journal of Soil Science
基金
国家自然科学基金项目(41771270)资助。
