川西漂洗土壤有效铁的时空分布特征

Temporal and Spatial Distribution Features of Effective Iron in Bleached Soil in the West Sichuan Basin

为了弄清土地利用/覆被改变后川西漂洗水稻土有效铁的时空分布特征,在四川省名山县第3～5级阶地上选取水田、由水田改造而成的旱地和不同种植年限的茶园样地,从地表至110 cm深度处,以土层深度10 cm为一个采样单位进行土样采集,并且与室内样品理化性质分析相结合,研究土地利用类型从水稻田变为茶园对漂洗土壤中有效铁组成的影响及漂洗水稻土中有效铁的动态变化.结果表明：土地利用方式的变化导致漂洗土壤有效铁含量在不同阶地与不同土层深度下变化都不一致;从土层剖面分布上看,有效铁含量都表现为表层较高,下层较低,在50 cm土层处有效铁含量急剧下降,越往下含量越少;从季节动态分布特征来看,土壤有效铁含量在9月份含量最高,且无明显的季节动态变化规律;漂洗土壤有效铁含量受pH、有机质、腐殖质等因素的显著影响.

In order to clarify the land use cover changes in Western Sichuan, and find out temporal and spatial distribution characteristics of available iron in bleached soil, we choice third to fifth terraces in Mingshan County, and selected by paddy field, paddy to transform into dry land and different planting years of tea sample, the surface to the depth of 110 cm, 10 cm with soil depth for a sampling unit for soil sampling, and the interior of the sample analysis of physicochemical properties of combining research methods, research on land use types from paddy field to tea garden to rinse soil available iron and the effect of bleached soil available iron dynamic change. The results showed that ： Land use changes lead to effective iron content, but different terrace and different soil depth change under the inconsistent. From soil profile distribu- tion, effective iron content are shown as the surface layer is higher, in the 50 cm soil effective iron content decreased dramatically, the longer the less content. Effective iron seasonal dynamic changes of no obvious rule ; Effective iron content is significantly influenced by pH, organic matter, humic substances and other factors.