不同利用方式棕壤的铝硅氧化物的分异特征

棕壤是我国重要的土壤资源,其特殊的气候地形条件决定了必须科学合理的开发利用才能保证该地区农业的可持续发展。本文对林地、蚕地、耕地3种利用方式下棕壤中铝硅氧化物的变化情况进行了研究。结果表明:(1)不同利用方式下,铝氧化物的无定形态在各层间差异较大。0~20 cm土层的游离硅、无定形铝均表现出随人为干预程度的提高而增加的趋势,反映出开垦的集约化加剧了土壤的风化作用。(2)从各形态氧化物在剖面间的分布来看,游离氧化硅、无定形铝的分布均呈向下富集的趋势,与粘粒在土体内的分布规律一致。活性硅与不同利用方式土壤的风化淋溶作用关系的规律性不明显,但可反映作物对硅的吸收特性。(3)开垦后土壤表层生物积累量的减少,影响了土壤表层活性硅的积累。

Characters of Aluminium and Silica Oxide in Brown Soil of Different Land Use Systems

Considered the special climate and terrain conditions,the sustainable development in brown soil zone need the theory of scientific use,the soil oxide under different land use systems of brown soil was studied.The results show: In contrast with the forest land,the three different soil layers of the silkworm land and cultivated land have different combined forms of soil oxides.Among the various oxides,total aluminium in every layer are not clearly different,and free and active oxides have relative strongly changes between different layers.In the 0~20 cm layer,the tendency of free silica and active aluminium,which quantities increases with the higher degree of interference of human activities, is displayed.As it showed that the cultivated processes have promote the degree of weathering.In addition,from the distribution of free silica oxide and amorphous aluminium in the solum,the tendencies of three substances congregate downwards and the regularity makes us understand the human effect under different land uses.At the same time,from this result that amorphous iron enriches in cultivated land we further learn the effect of the weathering and eluviation to solum.Active silica seems not to explain the effect on weathering and eluviation in different land uses,but it can show the degree of silica that surface crop absorbs after cultivating land.After cultivating,active silicon is reduced in surface layer.