Lithic soils in the semi-arid region of Brazil:edaphic characterization and susceptibility to erosion  

作　　者：Carlos R PINHEIRO JUNIOR Conan A SALVADOR Tiago R TAVARES Marcel C ABREU Hugo S FAGUNDES Wilk S ALMEIDA Eduardo C SILVA NETO Lúcia H C ANJOS Marcos G PEREIRA 

机构地区：[1]Federal Rural University of Rio de Janeiro(UFRRJ),Department of Soils,Seropédica,Rio de Janeiro 23890,Brazil [2]Center for Nuclear Energy in Agriculture(CENA),University of São Paulo(USP),Piracicaba,São Paulo 13416,Brazil [3]Federal Institute of Education,Science and Technology of Rondônia(IFRO),Rural Zone,Ariquemes,Rondônia 78930,Brazil

出　　处：《Journal of Arid Land》2022年第1期56-69,共14页干旱区科学（英文版）

基　　金：funded in part by the Coordination for the Improvement of Higher Education Personnel,Brazil(CAPES;Finance code 001);the Carlos Chagas Filho Foundation for Supporting Research in the State of Rio de Janeiro,FAPERJ.Tiago R TAVARES was funded by the São Paulo Research Foundation(FAPESP;2020/16670-9).

摘　　要：Soils(Leptosols or Epileptic Regosols)with lithic contact at a depth of 50 cm occupy almost 20%of the Brazilian semi-arid region.These lithic soils are susceptible to erosion due to faster saturation of water-holding capacity during rainfall,which accelerates the beginning of runoff.However,erosion traits of lithic soils in the semi-arid region of Brazil are less studied.The aim of this study was to characterize the soil and landscape attributes in areas with Neossolos Litólicos(Entisols)in the Caatinga biome to identify region of high susceptibility to erosion.Results showed that the soils were characterized by a sandy texture,soil structure with poor development and low content of organic carbon.These attributes increase susceptibility to erosion and reduce water storage capacity,especially in the states of Cearáand Sergipe.In these states,the content of rock fragments in the soil reaches 790 g/kg.High contents of silt and fine sand,high silt/clay ratio,predominance of Leptosols and strong rainfall erosivity were observed in Piauíand northwestern Ceará.A very high degree of water erosion was observed in the states of Pernambuco and Paraíba.Despite the low degree of erosion observed in the state of Bahia,it is highly susceptible to erosion due to the predominance of very shallow soils,rugged relief and high values of rainfall erosivity.Lower vulnerability was observed in the state of Alagoas because of its more smoothed relief,greater effective soil depth,thicker A horizon of soil and lower rainfall erosivity.In general,the characteristics that intensify the susceptibility to erosion in the Caatinga biome are those soil structures with poor development or without aggregation,low contents of organic carbon,high contents of silt and fine sand,high values of silt/clay ratio and rugged relief in some regions.This study collected information contributing to a better characterization of soils with lithic contact in the semi-arid region of Brazil.In addition,regions with a higher susceptibility to erosion were ide

关 键 词：Caatinga biome DRYLANDS erosive processes leptosols soil degradation 

分 类 号：S157.1[农业科学—土壤学]