张家口坝上地区土地利用方式对土壤理化性质的影响

Effects of land use patterns on soil physio-chemical properties in Zhangjiakou area

土壤理化性质作为土壤健康评价的重要指标,对土地利用方式响应敏感。为揭示张家口坝上地区土地利用类型对土壤理化性质的影响,本研究以张家口市坝上地区草地、林地、菜地和常规耕地4种主要土地利用类型为研究对象,分析了0~15 cm和15~30 cm土层的pH、容重、有机碳(SOC)、总氮(TN)、总磷(TP)和有效态微量元素等物理化学指标的性质差异及其影响因素。研究表明,表层(0~15 cm)土壤容重在四种土地利用类型中差异不显著,但菜地和耕地底层(15~30 cm)土壤容重(1.62 g·cm^(-3))显著高于林地(1.51 g·cm^(-3))和草地(1.37 g·cm^(-3)),表现出耕作导致的物理压实性。菜地和耕地表层和底层土壤pH显著低于林地和草地。菜地表层(0~15 cm)和底层(15~30 cm)土壤的SOC含量和TN含量在四种土地利用方式中最高,且有效铜(0.59 mg·kg^(-1))和有效锌(2.04 mg·kg^(-1))含量显著高于其余三种土地利用方式。草地(2.88 g·kg^(-1))和菜地土壤(2.86 g·kg^(-1))TP含量都显著高于林地和耕地。土壤SOC、TN和TP含量均与土壤粘粒含量呈极显著正相关关系;有效铁、锰和锌含量与土壤pH呈极显著负相关关系,有效铁、锰、铜和锌含量与SOC含量呈正相关关系。研究结果可为坝上地区土地资源科学管理和可持续利用提供基础支撑。

The soil physical and chemical property,as important index for soil health evaluation,is sensitive to land use patterns.In order to understand the effects of land use patterns on the soil physical and chemical property in the Bashang area of Zhangjiakou City,four main land use patterns including grassland,woodland,vegetable land and conventional cropland were selected,and then soil pH,bulk density,SOC,TN,TP and available trace elements in the 0~15 cm and 15~30 cm soil depths were analyzed.Results showed that,bulk densities of surface soil(0~15 cm)had no significant difference among the four land use types.However,bulk densities of subsurface soil(15~30 cm)in vegetable land and cropland(1.62 g·cm^(-3))were significantly higher than that in woodland(1.51 g·cm^(-3))and grassland(1.37 g·cm^(-3)),indicating the physical compaction caused by tillage.The pH of surface and subsurface soil of vegetable land and cropland was significantly lower than that of woodland and grassland.SOC contents and nitrogen content in vegetable soil of the 0~15 cm and 15~30 cm depth were with the highest value in 4 land use patterns,and the contents of available Cu(0.59 mg·kg^(-1))and available Zn(2.04 mg·kg^(-1))were significantly greater than those of other 3 land use patterns.TP contents of grassland(2.88 g·kg^(-1))and vegetable land(2.86 g·kg^(-1))were significantly higher than those of forestland and cropland.The contents of SOC,TN and TP were all significantly positively correlated with the content of soil clay particles;while the contents of available Fe,available Mn and available Zn were significantly negatively correlated with soil pH;there was a significant positive correlation between the content of SOC and contents available of Fe,Mn,Cu and Zn.These results can provide the foundation support for the scientific management and sustainable utilization of land resources in Bashang area.