摘要
以三峡库区消落带典型的紫色土为试验材料,通过原位试验研究不同淹水深度(0、2、5和15m)对土壤氮素形态转化和酶活性的影响。结果表明:淹水180d后,随着淹水深度的增加,铵态氮和硝态氮含量均逐渐降低;与未淹水(0m)对比,水深2m处的铵态氮含量增加显著,而水深15m处的硝态氮含量显著(P<0.05)减少。铵态氮和硝态氮含量对不同淹水深度的响应有显著差异(P<0.05)。对土壤无机氮(铵态氮+硝态氮)而言,水深15m处的无机氮含量比未淹水(0m)减少3.96mg/kg。脲酶和亚硝酸还原酶活性随淹水深度增加有所下降,而羟胺还原酶和硝酸还原酶活性呈先下降后上升的趋势,并均在水深2m处达到最大值。除脲酶外,其他酶活性均高于未淹水(0m)处理。
The purple soil is typical in the water-level-fluctuating zone of Three Gorges Reservoir.Nitrogen transformation and soil enzyme activities of the soil were investigated at four water depths(0,2,5and 15m)in situ experiment.Results showed that the contents of ammonium and nitrate decreased gradually with the increase of water depth after 180 days flooded.Compared with non-flooded(0m),the contents of ammonium increased significantly at 2 m depth and nitrate decreased significantly at 15 m depth(P<0.05).On the whole,soil ammonium and nitrate were significantly affected by water depth(P<0.05).The content of soil inorganic nitrogen(ammonium and nitrate)at 15 m depth was 3.96mg/kg lower than that of non-flooded soil.Activities of enzymes related with soil nitrogen transformation were significantly influenced by water depth(P<0.05).With the increase of water depth,the activities of urease and nitrite reductase showed a decreasing tendency.The activities of hydroxylamine reductase and nitrate reductase decreased first and then increased.Activities of all soil enzymes reached the maximum at 2mdepth.Except for urease,activities of other enzymes were higher than that of non-flooded soil.It is indicated that water depth has an important influence on nitrogen transformation and activities of soil enzymes.
出处
《华中农业大学学报》
CAS
CSCD
北大核心
2016年第5期33-38,共6页
Journal of Huazhong Agricultural University
基金
国家水体污染控制与治理重大专项(2013ZX07104-004)
三峡后续工作科研项目(2013HXKY2-3)
关键词
三峡库区
消落带
原位试验
淹水深度
季节性淹水落干
土壤氮素形态
酶活性
Three Gorges Reservoir
water-level-fluctuating zone
in situexperiment
water depth
seasonal flooding and drying
soil nitrogen forms
enzyme activity
