Elastic and plastic soil deformation and its influence on emission of greenhouse gases
Elastic and plastic soil deformation and its influence on emission of greenhouse gases
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DOI：
10.1515/intag-2015-0088
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发表时间：
2016-04-01
影响因子：
2.2
通讯作者：
Horn, Rainer
中科院分区：
文献类型：
--
作者：
Haas, Christoph;Holthusen, Doerthe;Horn, Rainer
土壤管理改变了土壤的物理、化学和生物特性。胁迫作用影响根区微生物活性和微生物栖息地，导致土壤退化。我们假设，如果超过土壤强度，应力施加会导致温室气体排放的改变。在试验中，采用两种实验装置，测定了完整土芯（不耕作、减少耕作和常规耕作）的土壤管理依赖的温室气体排放；采用动态测量系统和静室法对土壤施加垂直应力前后的CO2排放量进行了测定。对后者的CH4和N2O排放进行了分析。应力依赖效应可概括为：在弹性变形范围内，常规耕作土壤微生物活性增加，免耕和免耕土壤微生物活性降低。超过预压应力后，原受保护的土壤有机碳释放，CH4氧化性几乎全部丧失。只有免耕和减耕的胀缩作用才能恢复其微生境功能。因此，土壤强度和微生物活性之间的直接联系可以作为土壤刚度和微生物活性和组成向新的不平衡过渡的标志。
Soil management alters physical, chemical and biological soil properties. Stress application affects microbiological activity and habitats for microorganisms in the root zone and causes soil degradation. We hypothesized that stress application results in altered greenhouse gas emissions if soil strength is exceeded. In the experiments, soil management dependent greenhouse gas emissions of intact soil cores (no, reduced, conventional tillages) were determined using two experimental setups; CO2 emissions were determined with: a dynamic measurement system, and a static chamber method before and after a vertical soil stress had been applied. For the latter CH4 and N2O emissions were analyzed additionally. Stress dependent effects can be summed as follows: In the elastic deformation range microbiological activity increased in conventional tillage soil and decreased in reduced tillage and no tillage. Beyond the precompression stress a release of formerly protected soil organic carbon and an almost total loss of CH4 oxidizability occurred. Only swelling and shrinkage of no tillage and reduced tillage regenerated their microhabitat function. Thus, the direct link between soil strength and microbial activity can be applied as a marker for soil rigidity and the transition to new disequilibria concerning microbial activity and composition.