Spectroscopic characterization of humic acid fractions isolated from soil using different extraction procedures

Shirshova, L. T.; Ghabbour, Elham A.; Davies, Geoffrey

doi:10.1016/j.geoderma.2005.07.007

Cited by 94 publications

(20 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The three layers in the zonal structure of organo-mineral associations correspond well to our spectral observations of three layers (inner layer, middle layer, and surface layer) and demonstrate structural composition similar to two of the zones proposed by Kleber et al (2007). Soil organic matter is usually isolated from soil mineral surfaces using chemical or physical procedures, thereby enhancing acquisition of functional group and structural component information (Cheshire et al 2000;Shirshova et al 2006;Lehmann et al 2008). In this study, spectra were acquired from samples without chemical pretreatment; therefore, the functional group and structural component obtained should more closely mimic SOM structure found in the environment.…”

Section: Principal Component Analyses Of Pa Spectrasupporting

confidence: 79%

A 1915–2011 microscale record of soil organic matter under wheat cultivation using FTIR-PAS depth-profiling

Goyne

Miles

et al. 2013

Agron. Sustain. Dev.

View full text Add to dashboard Cite

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

show abstract

Section: Principal Component Analyses Of Pa Spectrasupporting

confidence: 79%

A 1915–2011 microscale record of soil organic matter under wheat cultivation using FTIR-PAS depth-profiling

Goyne

Miles

et al. 2013

Agron. Sustain. Dev.

View full text Add to dashboard Cite

show abstract

“…7). This region includes the amide bands that have been correlated with microbial biomass (Calderón et al, 2011a) or a carbonyl C=O band/aromatic C=C common in humified organic matter (Shirshova et al, 2006).…”

Section: Discussionmentioning

confidence: 99%

Diffuse-Reflectance Fourier-Transform Mid-Infrared Spectroscopy as a Method of Characterizing Changes in Soil Organic Matter

Calderón

Haddix

Conant

et al. 2013

Soil Science Society of America Journal

124

View full text Add to dashboard Cite

“…The accepted conceptual model for the formation of cavernous rock weathering in hot deserts involves the presence of permeable rocks that are subjected to soluble salts and repeated episodes of drying-rewetting cycles (Goudie et al, 2002;Smith, 1988;Smith et al, 2005). The proposed mechanisms assume that cavernous weathering results from physico-chemical processes including salt crystallization (Cooke, 1979;Scherer, 2004), incipient fractures (Amit et al, 1996), exfoliation (Shtober-Zisu et al, 2017), or stress erosion (Bruthans et al, 2014;McArdle and Anderson, 2001). Recently, Bruthans et al (2018) conclusively demonstrated that moisture flux followed by salt crystallization at the boundary layer govern the case hardening model in temperate climates.…”

Section: Introductionmentioning

confidence: 99%

The origin and role of biological rock crusts in rocky desert weathering

et al. 2019

View full text Add to dashboard Cite

Abstract. In drylands, microbes that colonize rock surfaces have been linked to erosion because water scarcity excludes traditional weathering mechanisms. We studied the origin and role of rock biofilms in geomorphic processes of hard lime and dolomitic rocks that feature comparable weathering morphologies, although these two rock types originate from arid and hyperarid environments, respectively. We hypothesized that weathering patterns are fashioned by salt erosion and mediated by the rock biofilms that originate from the adjacent soil and dust. We used a combination of microbial and geological techniques to characterize rock morphologies and the origin and diversity of their biofilms. Amplicon sequencing of the SSU rRNA gene suggested that bacterial diversity is low and dominated by Proteobacteria and Actinobacteria. These phyla only formed laminar biofilms on rock surfaces that were exposed to the atmosphere and burrowed up to 6 mm beneath the surface, protected by sedimentary deposits. Unexpectedly, the microbial composition of the biofilms differed between the two rock types and was also distinct from the communities identified in the adjacent soil and settled dust, showing a habitat-specific filtering effect. Moreover, the rock bacterial communities were shown to secrete extracellular polymeric substances (EPSs) that form an evaporation barrier, reducing water loss rates by 65 %–75 %. The reduced water transport rates through the rock also limit salt transport and its crystallization in surface pores, which is thought to be the main force for weathering. Concomitantly, the biofilm layer stabilizes the rock surface via coating and protects the weathered front. Our hypothesis contradicts common models, which typically consider biofilms to be agents that promote weathering. In contrast, we propose that the microbial colonization of mineral surfaces acts to mitigate geomorphic processes in hot, arid environments.

show abstract

Spectroscopic characterization of humic acid fractions isolated from soil using different extraction procedures

Cited by 94 publications

References 20 publications

A 1915–2011 microscale record of soil organic matter under wheat cultivation using FTIR-PAS depth-profiling

A 1915–2011 microscale record of soil organic matter under wheat cultivation using FTIR-PAS depth-profiling

Diffuse-Reflectance Fourier-Transform Mid-Infrared Spectroscopy as a Method of Characterizing Changes in Soil Organic Matter

The origin and role of biological rock crusts in rocky desert weathering

Contact Info

Product

Resources

About