川西漂洗水稻土亚铁时空分布对土地利用/覆被变化的响应  

Spatiotemporal Distribution Characteristics of Fe(Ⅱ) in Bleached Paddy Soil in the West Sichuan Basin and Its Response to LUCC

作　　者：袁大刚[1] 谭海燕[1,2] 程伟丽[3] 杨大东[1,4] 王昌全[1] 吴德勇[1] 

机构地区：[1]四川农业大学资源环境学院,四川温江611130 [2]成都南岩环境工程有限责任公司,成都610071 [3]四川农业大学林学院,四川雅安625014 [4]重庆市大足县规划局,重庆大足402360

出　　处：《水土保持学报》2012年第1期128-135,共8页Journal of Soil and Water Conservation

基　　金：国家自然科学基金青年基金项目(40801079);四川省科技富民强县重点项目(07NG001-020)

摘　　要：铁是环境敏感元素。为弄清土地利用/覆被改变后川西漂洗水稻土亚铁时空分布特征,在四川省名山县第三、四、五级阶地典型位置选取水田、由水田改造的旱地和不同种植年限的茶园样地,于2009年5,7,9月和2010年1,3月,按10cm间距从表层向下采集土壤样品,测定土壤亚铁含量及相关的含水量、氧化还原电位、还原物质总量、pH、总有机碳含量、腐殖质组成和活性铁含量等指标,探讨亚铁剖面分布特征、季节动态及其影响因素。结果表明,土地利用方式的改变及植茶年限的延长,改变了土壤水分状况、氧化还原电位、还原物质总量、活性铁等,使川西漂洗水稻土亚铁含量发生变化,但不同阶地其变化特征有所不同,第三级阶地和四级阶地从水田(旱地)到1年(3年)茶园再到6年茶园,土壤亚铁总体呈先下降后上升趋势,而第五级阶地从水田到3年茶园再到7年茶园,土壤亚铁总体上先升后降;现代微域还原环境或地质时期还原环境使部分剖面亚铁分布特征不再遵循从表层向下逐渐降低的规律,而是在土体下部有极丰富的亚铁积累,最高达4 739mg/kg;表层土壤亚铁含量的季节动态特征并未显著改变,以9月或7月为主要积累时期。研究可为该区土壤/土地资源合理利用提供一定参考。Iron is an environmentally sensitive element.In order to understand the temporal and spatial distribution characteristics of soil Fe（Ⅱ） in bleached paddy soil of the west Sichuan basin after land use/cover change,this study selected the paddy fields,dryland,and tea garden of different planting years transformed from paddy fields at the third,fourth,and fifth terraces in Mingshan county,Sichuan province as sampling plots.Firstly,soil samples were collected from the surface down by 10 cm space in May,July,September,2009,and January,March,2010.Then,the Fe（Ⅱ） content,soil moisture,redox potential,total reduced material,pH,total organic carbon,humus composition and amorphous iron and other indicators were measured.Finally,the vertical distribution,seasonal dynamics of soil Fe（Ⅱ） and its influencing factors were discussed.The results showed that land-use change and time extension of tea plantation,could change soil water status,redox potential,the amount of reduced material,and amorphous iron,so that soil Fe（Ⅱ） content in bleached paddy soil in the west Sichuan basin changed,but there were different features in different terraces.From the paddy fields（dry） to 1-year（3 years old） and then 6 years old tea garden on the third-level terraces and four terraces,soil Fe（Ⅱ） content decreased after the first drop overall,but from paddy fields to 3 years old and then to 7 years old tea garden on the fifth terrace,soil Fe（Ⅱ） content first rose and then decreased overall;modern micro-domain reducing environment or geologic-period reducing environment had caused soil Fe（Ⅱ） content no longer followed the distribution law that soil Fe（Ⅱ） content gradually decreased from top to bottom,but soil iron accumulated in the bottom,up to 4 739 mg/kg.The seasonal dynamic characteristics of soil Fe（Ⅱ） content in the topsoil had not significantly changed,and main accumulation period were in September or July.This study would provide a rational use for the soil/land resources in refere

关 键 词：亚铁 垂直分布 季节动态 水田 茶园 种植年限 

分 类 号：S153[农业科学—土壤学]