秦岭-黄淮平原交界带土壤物质迁移与积累

以横断秦岭－黄淮平原交界带中部的土壤断面为研究对象,应用土壤地球化学观点,讨论了交界带土壤物质迁移和积累规律。自西向东,随着海拔下降,土壤表层硅铝率逐渐增大,大部分土壤表层物质遵循迁移－积累－迁移－积累规律;“暖坡”地带是交界土壤地球化学活跃地段。并讨论了土壤物质迁移与土壤性质的关系．

A STUDY ON THE MIGRATION AND ACCUMULATION LAWS OF SOIL MATERIALS IN THE JUNCTURE OF QINLING-HUANGHUAI

The studied object in this paper is the soil section from west to east that acrosses the middle juncture of Qinling-Huanghuai. The migration and accumulation laws of soil material along the soil section above are discussed,based on the soil investigation outdoor and the physical-chemical experiment with soils indoor,and appling the view of soil geochemistry. The SiO2/R2O3 in soil surface layers increases gradually along the section from west to east with that height above sea level descends by degrees from weat to east. The soils which are above 700m above sea level accumulate Fe2O3 and MnO at small amount in surface layer,the other oxides are leaching out greatly. K2O and MgO in surface layer are leaching out at small amount in the soils which are between 600m-400m above sea level,the other oxides accumulate greatly. The bulk of oxides in surface layer are leaching out greatly in the soils which are between 300m- 150m above sea level. Fe2O3 in surface layer is leaching out at small amount in the soils which are below 150m above sea level,The other oxides accumulate greatly. The bulk of soil materials in surface layer abide by the law of migration accumulation migration- accumulation along the section from west to east , and it abides by the law of accumulation migration accumulation in the juncture of Qinling Huanghuai from west to east. The "warm belt" is the belt in which soil geochemical processes are activest in the juncture. Finally,some relations between the migration of soil materials and pH, content of organic matter,texture of soils are discussed.