封丘县典型农田土壤质量与时空变化特征

Spatial and Temporal Dynamics of Soil Quality in Representative Farmland of Fengqiu County

黄淮海平原作为我国重要的粮食产区,系统全面地评价该区域典型潮土的质量变化,对指导农业生产具有重要意义。以典型潮土分布的封丘县作为研究区,选取1984、2003和2011年的17项土壤指标,基于土壤参与生态过程中作物生产、碳固存、持水净化和养分运移等功能,构建土壤综合质量评价系统,采用主成分分析结合逼近理想点排序法(TOPSIS)计算各功能得分及土壤质量综合指数,通过GIS空间插值描述封丘县27年内潮土耕作区土壤质量和功能的时空变化特征。结果表明:(1)封丘县土壤全氮、全磷、碱解氮、有效磷、速效钾和有机质含量及阳离子交换量、饱和导水率和孔隙度均呈现不同程度的提升趋势;全钾含量、pH、容重、田间持水量和有效含水量则呈逐年降低趋势;(2)封丘县土壤作物生产、碳固存和养分运移功能得分均有所提升,增长率分别为9.29%、9.68%和7.36%,持水净化功能得分则降低4.17%;(3)封丘县土壤质量综合指数提升较为明显,1984年全县耕地土壤质量综合指数均≤2.0,2003年综合指数>2.0的耕地面积占全县总面积的8.44%,2011年提升至24.05%。整体而言,封丘县该时期的耕地保护和利用模式基本是有效的,封丘县耕地整体质量不断向好的方向发展,相关结果可以为黄淮海地区耕地资源可持续利用提供参考。

The Huang-Huai-Hai Plain is an important agricultural region in China,taking an overall system evaluation of its typical soil quality changes holds great significance in guiding agricultural production.Fengqiu County was chosen as the study area,and the data of the typical tidal soil of the county of the years of 1984,2003,and 2011 consisting of 17 soil indexes were used.These indexes were based on soil functions within ecological processes such as crop production,carbon sequestration,water purification,nutrient transport,and others,to construct an integrated soil quality evaluation system.Functional scores and the comprehensive index of soil quality were computed using principal component analysis combined with the TOPSIS ranking method.The spatial and temporal changes of the 27 years in soil quality and function within the tidal soil tillage area of Fengqiu County were depicted through GIS spatial interpolation.The results reveal:(1)The levels of soil total nitrogen,total phosphorus,alkaline nitrogen,available phosphorus,available potassium,organic matter,cation exchange capacity,saturated hydraulic conductivity,and porosity in Fengqiu County displayed varying degrees of increasing trends,while total potassium content,pH levels,bulk density,field water capacity,and available water content decreased annually.(2)Soil functions related to crop production,carbon sequestration,and nutrient transport in Fengqiu County increased by 9.29%,9.68%,and 7.36%,respectively,while the score for water retention and purification function decreased by 4.17%.(3)The comprehensive index of soil quality improvement in Fengqiu County became more apparent.In 1984,all the comprehensive index of soil quality in farmland across the county was≤2.0,while by 2003,the area with the index>2.0 accounted for 8.44% of the total county area,and the percentage of the area with the index>2.0 was further raised to 24.05% in 2011.Overall,the protection and utilization strategies for cultivated land in Fengqiu County over the 27 years were proven to be largely effective,leading to a continuous development towards improved overall quality.These findings can serve as a reference for sustainable use of cultivated land resources in the Huang-Huai-Hai Region.