Organic Matter Study of Whole Soil Samples Using Laser-Induced Fluorescence Spectroscopy

2006 ◽  
Vol 70 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Débora Marcondes Bastos Pereira Milori ◽  
Helder Vinicius Avanço Galeti ◽  
Ladislau Martin-Neto ◽  
Jeferson Dieckow ◽  
Martha González-Pérez ◽  
...  
2021 ◽  
Vol 211 ◽  
pp. 105001
Author(s):  
Amanda M. Tadini ◽  
Alfredo A.P. Xavier ◽  
Débora M.B.P. Milori ◽  
Patrícia P.A. Oliveira ◽  
José R. Pezzopane ◽  
...  

2020 ◽  
Author(s):  
Amanda Maria Tadini ◽  
Alfredo Augusto Pereira Xavier ◽  
Ladislau Martin-Neto ◽  
Débora Marcondes Bastos Pereira Milori ◽  
Alberto Carlos de Campos Bernardi

<p>The Integrated Crop-Livestock-Forest Systems (CLF) have been able to capture and store the carbon (C) in the form of Soil Organic Matter (SOM), in different regions in Brazil, thereby contributing to mitigate agricultural greenhouse gases emission. This is an eligible practice in Low Carbon Emission Agriculture Plan in Brazil, and currently has around 15 million hectares under use, a very positive and important trend in soil land use in Brazil. SOM is considered a relevant indicator of soil quality due to its direct relationship with biological, chemical, and physical properties, allowing it to evaluate the impacts of agricultural management. Laser-based spectroscopies as Laser-Induced Fluorescence Spectroscopy (LIFS) and Laser-Induced Breakdown Spectroscopy (LIBS) have become promising tools in the evaluation of the SOM in agricultural soils. LIBS can measure soil C, and LIFS can infer about the chemical structure of SOM, mainly aromaticity. The standard protocol for measuring soil C changes involves soil sampling at the field and chemical sample preparation for laboratory analysis. Although this procedure produces precise results, it takes time, generates chemical residues, and the costs restrict its routine for large scale use in agricultural projects. Thus, there is a need to develop clean (green chemistry), rapid, precise, and cost-efficient methods for measuring soil C changes in the field. Also, information about the chemical structure of SOM usually is done through spectroscopic techniques, such as <sup>13</sup>C NMR, EPR, and fluorescence of humic acid, which are not applied for large scale measurement and mapping. LIFS can be applied in whole soil and can be used to evaluate the aromaticity of SOM, and consequently, its chemical stability.  The objectives of this study were to evaluatethe soil C stock and SOM Stability of some Brazilian soils under different integrated systems, such as,Crop-Livestock-Forest (CLF), Crop-Livestock (CL) and Livestock-Forest(LF). The results showed the combination of soil carbon accumulation, and an increase of SOM aromaticity for CLF, which can be promising for sustainable intensification in agriculture.</p><p><strong>Keywords: </strong>Sustainable Intensification; Soil Organic Matter; Carbon stock; Laser-Induced Fluorescence Spectroscopy; Integrated Crop-Livestock-Forest Systems</p>


2014 ◽  
Vol 13 (4) ◽  
pp. 353-365 ◽  
Author(s):  
B. L. Berg ◽  
J. Ronholm ◽  
D. M. Applin ◽  
P. Mann ◽  
M. Izawa ◽  
...  

AbstractThe ability to discriminate biogenic from abiogenic calcium carbonate (CaCO3) would be useful in the search for extant or extinct life, since CaCO3can be produced by both biotic and abiotic processes on Earth. Bioprecipitated CaCO3material was produced during the growth of heterotrophic microbial isolates on medium enriched with calcium acetate or calcium citrate. These biologically produced CaCO3, along with natural and synthetic non-biologically produced CaCO3samples, were analysed by reflectance spectroscopy (0.35–2.5 μm), Raman spectroscopy (532 and 785 nm), and laser-induced fluorescence spectroscopy (365 and 405 nm excitation). Optimal instruments for the discrimination of biogenic from abiogenic CaCO3were determined to be reflectance spectroscopy, and laser-induced fluorescence spectroscopy. Multiple absorption features in the visible light region occurred in reflectance spectra for most biogenic CaCO3samples, which are likely due to organic pigments. Multiple fluorescence peaks occurred in emission spectra (405 nm excitation) of biogenic CaCO3samples, which also are best attributed to the presence of organic compounds; however, further analyses must be performed in order to better determine the cause of these features to establish criteria for confirming the origin of a given CaCO3sample. Raman spectroscopy was not useful for discrimination since any potential Raman peaks in spectra of biogenic carbonates collected by both the 532 and 785 nm lasers were overwhelmed by fluorescence. However, this also suggests that biogenic carbonates may be identified by the presence of this organic-associated fluorescence. No reliable spectroscopic differences in terms of parameters such as positions or widths of carbonate-associated absorption bands were found between the biogenic and abiogenic carbonate samples. These results indicate that the presence or absence of organic matter intimately associated with carbonate minerals is the only potentially useful spectral discriminator for the techniques that were examined, and that multiple spectroscopic techniques are capable of detecting the presence of associated organic materials. However, the presence or absence of intimately associated organic matter is not, in itself, an indicator of biogenicity.


2010 ◽  
Vol 59 (1) ◽  
pp. 99-108 ◽  
Author(s):  
M. Takács ◽  
Gy. Füleky

The Hot Water Percolation (HWP) technique for preparing soil extracts has several advantages: it is easily carried out, fast, and several parameters can be measured from the same solution. The object of this study was to examine the possible use of HWP extracts for the characterization of soil organic matter. The HPLC-SEC chromatograms, UV-VIS and fluorescence properties of the HWP extracts were studied and the results were compared with those of the International Humic Substances Society (IHSS) Soil Humic Acid (HA), IHSS Soil Fulvic Acid (FA) and IHSS Suwannee Natural Organic Matter (NOM) standards as well as their HA counterparts isolated by traditional extraction methods from the original soil samples. The DOM of the HWP solution is probably a mixture of organic materials, which have some characteristics similar to the Soil FA fractions and NOM. The HWP extracted organic material can be studied and characterized using simple techniques, like UV-VIS and fluorescence spectroscopy.


Author(s):  
Jeonghyun Kim ◽  
Yeseul Kim ◽  
Sung Eun Park ◽  
Tae-Hoon Kim ◽  
Bong-Guk Kim ◽  
...  

AbstractIn Jeju Island, multiple land-based aquafarms were fully operational along most coastal region. However, the effect of effluent on distribution and behaviours of dissolved organic matter (DOM) in the coastal water are still unknown. To decipher characteristics of organic pollution, we compared physicochemical parameters with spectral optical properties near the coastal aquafarms in Jeju Island. Absorption spectra were measured to calculate the absorption coefficient, spectral slope coefficient, and specific UV absorbance. Fluorescent DOM was analysed using fluorescence spectroscopy coupled with parallel factor analysis. Dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) were measured using high-temperature catalytic oxidation. The DOC concentration near the discharge outlet was twice higher than that in natural groundwater, and the TDN concentration exponentially increased close to the outlet. These distribution patterns indicate that aquafarms are a significant source of DOM. Herein, principal component analysis was applied to categorise the DOM origins. There were two distinct groups, namely, aquaculture activity for TDN with humic-like and high molecular weights DOM (PC1: 48.1%) and natural biological activity in the coastal water for DOC enrichment and protein-like DOM (PC2: 18.8%). We conclude that the aquafarms significantly discharge organic nitrogen pollutants and provoke in situ production of organic carbon. Furthermore, these findings indicate the potential of optical techniques for the efficient monitoring of anthropogenic organic pollutants from aquafarms worldwide.


Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 373
Author(s):  
Jonathan Suazo-Hernández ◽  
Erwin Klumpp ◽  
Nicolás Arancibia-Miranda ◽  
Patricia Poblete-Grant ◽  
Alejandra Jara ◽  
...  

Engineered nanoparticles (ENPs) present in consumer products are being released into the agricultural systems. There is little information about the direct effect of ENPs on phosphorus (P) availability, which is an essential nutrient for crop growthnaturally occurring in agricultural soils. The present study examined the effect of 1, 3, and 5% doses of Cu0 or Ag0 ENPs stabilized with L-ascorbic acid (suspension pH 2–3) on P ad- and desorption in an agricultural Andisol with total organic matter (T-OM) and with partial removal of organic matter (R-OM) by performing batch experiments. Our results showed that the adsorption kinetics data of H2PO4− on T-OM and R-OM soil samples with and without ENPs were adequately described by the pseudo-second-order (PSO) and Elovich models. The adsorption isotherm data of H2PO4− from T-OM and R-OM soil samples following ENPs addition were better fitted by the Langmuir model than the Freundlich model. When the Cu0 or Ag0 ENPs doses were increased, the pH value decreased and H2PO4− adsorption increased on T-OM and R-OM. The H2PO4− desorption (%) was lower with Cu0 ENPs than Ag0 ENPs. Overall, the incorporation of ENPs into Andisols generated an increase in P retention, which may affect agricultural crop production.


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