黔西北不同利用类型土壤全磷及有效磷的分布与残留

在黔西北关门山小流域选取5种主要的土地利用类型,研究不同土地利用类型下土壤全磷及有效磷的分布与残留特征,以期为当地生态环境保护和科学施磷提供一定的理论依据。结果表明,灌木林地坡面表层土壤全磷含量总体高于乔木林地,有效磷含量无明显分布规律。在坡顶、坡中和坡脚3个位置,乔木林地和灌木林地土壤剖面全磷和有效磷含量总体均随着土层深度的增加而减小,以表层最高,坡中和坡脚处0~60 cm土层全磷含量高于坡顶;乔木林地坡中和坡顶处土壤剖面全磷分别在80~100 cm和60~80 cm土层附近出现累积现象,但坡脚没有。5种利用类型土壤剖面全磷和有效磷含量均以表层最高,随着土层深度增加总体呈降低趋势,果园土壤剖面全磷含量远高于其他土地利用类型;表层土壤有效磷含量以玉米地最高,乔木林地最低。在0~80 cm土层中,乔木林全磷残留量最低,仅为1 783.7 kg/hm~2,果园全磷残留量最高,达3 416.0 kg/hm~2,显著高于其他土地利用类型;有效磷残留量以灌木林地最低,撂荒地最高,但不同土地利用类型间差异不显著。

Distribution and Residue of Soil Total P and Available P under Different Land Use Types in Northwest Guizhou

The research selected five land use types in the Guanmenshan small watershed in northwest Guizhou,and studied the distribution and residue characteristics of total P and available P in different land use types of soil,so as to provide a theoretical basis for local ecological environment protection and scientific application of phosphorus fertilizer.The results showed that the content of total P in the surface soil in shrub land was higher than that in arbor land,but the distribution of available P content was not regular.In the three positions of slop top,slop middle and slop bottom,the contents of total P and available P decreased with the increase of soil depth in the soil profiles of arbor and shrub lands,and were highest in 0-20 cm soil layer,total P contents in slope middle and slope bottom were higher than that in slope top in 0-60 cm soil layer;total P accumulated in 80-100 cm and 60-80 cm soil layer in the slop middle and slop top of arbor land respectively,but accumulation phenomenon did not appear in the slope bottom.For five land use types,the contents of total P and available P were highest in 0-20 cm soil layer,and decreased with the increase of soil depth,and the total P content was higher in the soil profile in orchard than that in other land use types;available P content was the highest in the soil profile in corn field,and lowest in arbor land.Residual rate of total P was the lowest in 0-80 cm soil layer in arbor land with 1 783.7 kg/ha,and highest in orchard with 3 416.0 kg/ha,which was significantly higher than that in other land use types;residual rate of available P was the lowest in shrub land,and highest in abandoned land,but the difference was not significant among different land use types.