不同土地利用方式对土壤氮磷和重金属含量的影响

Effects of Different Land Use Types on the Contents of Nitrogen, Phosphorus and Heavy Metals in Soil

以贵州威宁草海流域为研究对象,采用现场采样及室内分析测试方法,研究了流域不同土地利用方式对土壤氮磷和重金属的影响及土壤氮磷与重金属之间的相关性。结果表明:土壤总氮、总磷含量均表现为梯平地>城镇用地>坡耕地>草地>林地,梯平地和城镇用地显著高于草地和林地(P<0.05),坡耕地显著高于林地(P<0.05),梯平地、城镇用地和坡耕地,草地和林地均差异不显著(P>0.05);镉含量表现为城镇用地(3.44 mg·kg^(-1))>梯平地(3.16 mg·kg^(-1))>坡耕地(2.72 mg·kg^(-1))>草地(1.81 mg·kg^(-1))>林地(1.56 mg·kg^(-1)),锌含量表现为城镇用地(210.10 mg·kg^(-1))>梯平地(203.67 mg·kg^(-1))>坡耕地(198.86 mg·kg^(-1))>林地(125.53 mg·kg^(-1))>草地(110.49 mg·kg^(-1)),土壤镉、锌含量在城镇用地、梯平地和坡耕地中差异不显著(P>0.05),但均显著高于草地和林地(P<0.05),草地与林地差异不显著(P>0.05);总氮、总磷、镉和锌两两之间均呈显著或极显著的正相关关系。综上所述,不同土地利用方式影响着土壤氮磷和土壤重金属含量,与草地和林地相比,城镇用地、梯平地和坡耕地含量较高,土壤总氮、总磷、镉和锌的输入具有一定的同源性。

Take the Caohai basin of Weining in Guizhou Province as the research object,the effects of different land use types on the contents of total nitrigen,total phosphorus and heavy metals in the soil and the correlation during soil nitrigen,phosphorus and heavy metal were studied by field sampling and laboratory analysis.The results showed that the total nitrogen and total phosphorus contents in the soil were as shown in flat cultivated land>urban land>slope cropland>grassland>forest land.The flat cultivated land and urban land were significantly higher than grassland and forest land(P<0.05),and the slope cropland was significantly higher than the forest land(P<0.05).The flat cultivated land,urban land and slope cropland were not significantly different,grassland and forest land were not significantly different(P>0.05).Cd content was expressed as urban land(3.44 mg·kg-1)>flat cultivated land(3.16 mg·kg-1)>slope cropland(2.72 mg·kg-1)>grassland(1.81 mg·kg-1)>forest land(1.56 mg·kg-1).Zn content was expressed as urban land(210.10 mg·kg-1)>flat cultivated land(203.67 mg·kg-1)>slope cropland(198.86 mg·kg-1)>forest land(125.53 mg·kg-1)>grassland(110.49 mg·kg-1).The contents of Cd and Zn were not significantly different during urban land,flat cultivated land and slope cropland(P>0.05),and were significantly higher than that of grassland and forest land(P<0.05),and the difference between grassland and forest land was not significant(P>0.05).There was a significant or extremely significant positive correlation between TN,TP,Cd and Zn.To sum up,different land use types affect the contents of total nitrogen total phosphorus and soil heavy metals in the soil.The urban land,flat cultivated land and slope cropland had higher content than the grassland and forest land.At the same time,soil nutrients had certain homology with soil heavy metal input.