Sequential transformation rates of soil organic sulfur fractions in two-step mineralization process
Sequential transformation rates of soil organic sulfur fractions in two-step mineralization process
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DOI：
10.1007/s00374-013-0849-8
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发表时间：
2014-02
影响因子：
6.5
通讯作者：
T. Tanikawa;K. Noguchi;K. Nakanishi;H. Shigenaga;Junko Nagakura;H. Sakai;A. Akama;Masamichi Takahashi
中科院分区：
文献类型：
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作者：
T. Tanikawa;K. Noguchi;K. Nakanishi;H. Shigenaga;Junko Nagakura;H. Sakai;A. Akama;Masamichi Takahashi
为了了解火山岩土壤中有机硫（S）的稳定性，采用日本中部尼科火山岩地区的森林土壤，通过培养实验研究了有机硫的转化率及其与土壤性质的关系。我们假设碳（C）键合的S将首先转化为酯硫酸盐-S，然后转化为无机硫酸盐-S。我们分别计算了C-键合的S（速度1，v1）和酯硫酸盐-S（速度2，v2）浓度的降低速率。在培养过程中，硫酸酯-S浓度增加，其特征在于由高浓度的铵可提取铝（Alo）和焦磷酸盐可提取铝（Alp）的两种土壤，而C-键合的S浓度在所有土壤中下降。在孵育实验中损失的大部分S由C-键合的S而不是酯硫酸盐-S组成。在20 °C培养条件下，流速2与Alo和Alp含量均呈负相关。这些结果表明，当C-键合的S转化为酯硫酸盐-S，完全矿化无机硫酸盐被抑制，因为酯硫酸盐-S是稳定的，由于有机-无机协会。孵育温度显著影响v2。因此，生产无机硫酸盐的矿化酯硫酸盐-S出现调节土壤铝含量和温度。速度1是成正比的土壤pH值范围从4.5至5.5，表明降解的C-键合的S是pH值依赖性。
To understand the organic sulfur (S) stabilization in volcanic soils, we investigated organic S transformation rates and their relationships to soil properties in incubation experiments using forest soils from the Nikko volcanic region, central Japan. We hypothesized that carbon (C)-bonded S would first be transformed into ester sulfate-S and then into inorganic sulfate-S. We separately calculated the rates of decrease of C-bonded S (velocity 1,v1) and ester sulfate-S (velocity 2,v2) concentrations. During incubation, the ester sulfate-S concentration increased in two soils characterized by a high concentration of both ammonium oxalate-extractable aluminum (Alo) and pyrophosphate-extractable Al (Alp), whereas the C-bonded S concentration decreased in all soils. A large proportion of the S that was lost in the incubation experiments consisted of C-bonded S rather than ester sulfate-S. Velocity 2 was negatively correlated with both of Aloand Alpcontents when soils were incubated at 20 °C. These results suggest that when C-bonded S is transformed into ester sulfate-S, complete mineralization to inorganic sulfate is inhibited, because ester sulfate-S is stabilized due to organo–mineral association. Incubation temperatures significantly affectedv2. Thus, production of inorganic sulfate by mineralization of ester sulfate-S appeared to be regulated by soil Al contents and temperatures. Velocity 1 was proportional to soil pH ranging from 4.5 to 5.5, indicating that the degradation of C-bonded S is pH dependent.