摘要
以原位测定资料作基础,首次系统地总结了我国主要自然土壤、旱作土壤和水稻土的氧化还原状况。自然土壤、旱作土壤同属于氧化性土壤,Eh为440～730mV,还原性物质量相当于Mn2+0.00～4.01×10-5molL-1,一年内基本上处于氧化状态,物质转化迁移微弱;水稻土的Eh为670～-70mV,还原性物质量相当于Mn2+0.01～17.8×10-5molL-1,变动范围从氧化性到还原性,氧化还原状况随水分条件而周期性变化,物质转化迁移的强度和速度远甚于前两者;依据水稻土的氧化还原状况,可将其划分为氧化性、氧化还原性、还原性三种类型;土壤氧化还原状况的特点为:Eh与还原性物质量之间相关性良好、具水平带谱和垂直带谱分异、不均一性显著、变动的范围宽和变化的可逆性强。
Based on the results of in-situ determination using electrochemical methods, oxidation-reduction regimes of major natural soils, upland soils and paddy soils in China were systematically summarized for the first time. The natural soils and upland soils belonged to the category of oxidizing soil, with Eh in the range of 440 - 730 mV, and content of reducing substances equal to 0.00 - 4.01 × 10^-5mol L^-1 of Mn^2＋ , and remained basically oxidizing within a year, oxygen being the Eh-determinging factor and quite weak in transformation and translocation of materials in the soils, while the paddy soils ranged between 670 - -70 mV in Eh, with the content of reducing substances equal to 0.01 - 17.8 × 10^-5mol L^-1 of Mn^2＋ , and reducing substances being the Eh-determining role. And their material transformation/translocation intensity and sPeed was far greater than that in the natural soils and upland soils. In terms of oxidation-reduction regime varying periodically with water regime, paddy soils could be divided into three types, i. e. oxidizing, oxidizing-reducing and reducing. Soil oxidation-reduction regime is characterized by close correlation between Eh and content of reducing substances, spatial and horizontal variation, heterogeneity, wider range of variation and high reversibility. Determination in situ with electrochemical methods has paved a way to research of oxidation-reduction properties of weakly reducing soils.
出处
《土壤学报》
CAS
CSCD
北大核心
2008年第1期66-75,共10页
Acta Pedologica Sinica
关键词
氧化还原状况
原位测定
自然土壤
旱作土壤
水稻土
Oxidaton-reduction regime
Determination in situ
Natural soil
Upland soil
Paddy soil
