• 中文核心期刊
  • CSCD来源期刊
  • 中国科技核心期刊
  • CA、CABI、ZR收录期刊

石砌深窄沟长期排水对冷浸田土壤C、N、P化学计量及酶活性的影响

Nutrient Content and Enzyme Activity of Cold-waterlogged Soil in Fields with Open Drainage Ditches

  • 摘要: 通过连续30a的冷浸田开沟排水定位平台, 研究石砌深窄沟改造冷浸田不同离沟距离的土壤C、N、P生态化学计量学特征及土壤酶活性。结果表明, 离沟5、15、25m位点土壤, 与典型冷浸田位点 (离沟75m位点, CK) 相比, 土壤全C、全P含量均呈下降趋势。离沟5、15、25m位点土壤C/N值分别较CK降低2.56、1.03、0.91个单位, 差异均显著。过氧化氢酶、转化酶活性变化趋势与C/N值一致, 525m位点二者分别较CK降低0.3%10.0%、36.6%62.5%;而脲酶、酸性磷酸酶、硝酸还原酶活性与CK相比均呈上升趋势, 且过氧化氢酶、转化酶活性随着离沟距离的增加而提高, 酸性磷酸酶、硝酸还原酶则随离沟距离的增加而降低。土壤C、N、P含量间存在显著相关性, 但三者与土壤酶无显著相关, 而土壤C/N值与脲酶、磷酸酶及硝酸还原酶呈显著相关。上述说明, C/N值较单一的有机碳与全N指标更能体现土壤酶间的关系, 土壤C/N值可作为冷浸田改造效果评价的一个参考指标。

     

    Abstract: With a 30-year-old drainage ditch system in a field of cold-waterlogged soil, the ecological stoichiometry characteristics of C, N, P and enzyme activity of the soil was studied.The results showed that the total C, N (except for the 5msite) and P in the soils from the 5, 15 and 25msites (which were 5, 15 and 25m, respectively, away from the ditch) were significantly lower than those of the control (i.e., a typical cold-waterlogged soil site, which was 75 maway from the ditch) .The C/N ratio of the soil at 5, 15 and 25msites, reduced significantly by2.56, 1.03 and 0.91 units, respectively.Similarly, the enzyme activities of catalase and invertase declined by 0.3%-10.0% and 36.6%-62.5%, respectively.On the other hand, the activities of urease, phosphatase and nitrate increased 117.6%, 393.2% and 796.3%, respectively, at the 5msite.There was a significant correlation among C, N and P, as well as between the C/N ratio and the urease, phosphatase and nitrate activities.It appeared that the C/N ratio could be used as an index in evaluating the transforming effect of cold-waterlogged soils.

     

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