{"title":"Changes in the magnetic properties of a tropical red soil following the conversion of forest into agricultural land","authors":"","doi":"10.1016/j.jappgeo.2024.105471","DOIUrl":null,"url":null,"abstract":"<div><p>Land uses have a large impact on the magnetic properties of soil. Understanding the changes in such properties caused by different land uses will help to correctly explain and apply magnetic parameters. In this study, the magnetic susceptibility, magnetic mineral types, and magnetic domain state of iron oxide particles in soil after the transformation of a forest into a tea garden and cornfield in a tropical area were compared. 1)The vertical distribution characteristics of soil magnetism under the three land uses in tropical red soil area were similar. The magnetic properties of soil in the 0–20 cm surface layer was significantly different, but there were no significant differences below 20 cm. The low-frequency mass magnetic susceptibility and anhysteretic susceptibility of topsoil were largest in the cornfield, followed by the forest and tea garden, and the magnetic susceptibility of the topsoil in the cornfield was significantly higher than in the tea garden and forest. 2)The magnetic minerals in tropical red soil area were mainly ferrimagnetic minerals (maghemite and magnetite). The content of ferrimagnetic minerals decreased with depth, while the content of antiferromagnetic minerals (hematite) increased. 3)The magnetic particles were mainly composed of superparamagnetic (SP), single domain (SD), and pseudo single domain (PSD) particles. The magnetic differences in the topsoil were mainly caused by changes in the ferrimagnetic mineral concentration of SD particles. Tea garden and cornfield are the two main agricultural land in the study area. Through the correct application of magnetic parameters, it is helpful to monitor the influence of land use change on soil properties, so as to provide the necessary reference for the rational use of soil.</p></div>","PeriodicalId":54882,"journal":{"name":"Journal of Applied Geophysics","volume":null,"pages":null},"PeriodicalIF":2.2000,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Applied Geophysics","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0926985124001873","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Land uses have a large impact on the magnetic properties of soil. Understanding the changes in such properties caused by different land uses will help to correctly explain and apply magnetic parameters. In this study, the magnetic susceptibility, magnetic mineral types, and magnetic domain state of iron oxide particles in soil after the transformation of a forest into a tea garden and cornfield in a tropical area were compared. 1)The vertical distribution characteristics of soil magnetism under the three land uses in tropical red soil area were similar. The magnetic properties of soil in the 0–20 cm surface layer was significantly different, but there were no significant differences below 20 cm. The low-frequency mass magnetic susceptibility and anhysteretic susceptibility of topsoil were largest in the cornfield, followed by the forest and tea garden, and the magnetic susceptibility of the topsoil in the cornfield was significantly higher than in the tea garden and forest. 2)The magnetic minerals in tropical red soil area were mainly ferrimagnetic minerals (maghemite and magnetite). The content of ferrimagnetic minerals decreased with depth, while the content of antiferromagnetic minerals (hematite) increased. 3)The magnetic particles were mainly composed of superparamagnetic (SP), single domain (SD), and pseudo single domain (PSD) particles. The magnetic differences in the topsoil were mainly caused by changes in the ferrimagnetic mineral concentration of SD particles. Tea garden and cornfield are the two main agricultural land in the study area. Through the correct application of magnetic parameters, it is helpful to monitor the influence of land use change on soil properties, so as to provide the necessary reference for the rational use of soil.
土地利用对土壤的磁性有很大影响。了解不同土地利用方式导致的磁性变化有助于正确解释和应用磁性参数。本研究比较了热带地区森林变为茶园和玉米田后土壤中氧化铁颗粒的磁感应强度、磁性矿物类型和磁畴状态。1)热带红壤区三种土地利用方式下的土壤磁性垂直分布特征相似。0-20 cm 表层土壤的磁性有显著差异,但 20 cm 以下无显著差异。玉米田表土的低频质量磁感应强度和非稳态磁感应强度最大,森林和茶园次之,玉米田表土的磁感应强度明显高于茶园和森林。2)热带红壤区的磁性矿物主要是铁磁性矿物(方镁石和磁铁矿)。随着深度的增加,铁磁性矿物的含量减少,而反铁磁性矿物(赤铁矿)的含量增加。3)磁性颗粒主要由超顺磁性(SP)、单域(SD)和伪单域(PSD)颗粒组成。表层土壤的磁性差异主要是由 SD 颗粒中铁磁性矿物浓度的变化引起的。茶园和玉米田是研究区域的两大主要农田。通过正确应用磁参数,有助于监测土地利用变化对土壤性质的影响,从而为合理利用土壤提供必要的参考。
期刊介绍:
The Journal of Applied Geophysics with its key objective of responding to pertinent and timely needs, places particular emphasis on methodological developments and innovative applications of geophysical techniques for addressing environmental, engineering, and hydrological problems. Related topical research in exploration geophysics and in soil and rock physics is also covered by the Journal of Applied Geophysics.