The examination of humic substances in soils and composts with high organic content with different methods

The organic materials, especially the complex structural humic substances are acid-characteristic polymers which are key elements of soils. Despite their relatively small quantity, humic substances have beneficial effects on soil nutrient management, development of optimal soil structure, regulation of soil temperature, and proper water management. The application of the UV-VIS spectrophotometry for describing humic substances in soils and determining of humifical state is nowadays a widespread method. The E4/E6 procedure (which were determined between 465 and 665 nm wavelength) and the Hargitai-method (the extinction of extracts measured between 400 and 750 nm at 9 wavelength) are procedures that have become the general tool for determining the quality of humic matters because of its easy accessibility and smaller need of instrumentations. Nevertheless, their usefulness has been criticized in scientific communities because of the high human error factor and the technical limitations of the simpler spectrophotometric instruments. Nowadays the spreading light scattering photometric examinations using lasers as the Static Light Scattering (SLS) or the Dynamic Light Scattering (DLS) could be a new way of measuring the quality of the humic matters. This study is based on the examination of different quality soil and compost samples which were extracted from different Hungarian sites like Trizs, Szárítópuszta and Csobánc. Additionally, not only the soils and composts were analyzed but also any soil conditioners (biochar, bone charcoal) which were applied and affected their properties. The main goal of the research was to measure the soil and compost samples with the E4/E6 and the Hargitai-method and with also using Zetasizer Nano ZS device that could lead to more detailed results about the weight and the size of the humic molecules. Based on the summarized analytic results the outcomes of the E4/E6 procedure is applicable for drawing relevant conclusion regarding the humic quality of the given sample. On the contrary, the applied Hargitai-method has not proved to be effective. Although the measurement of the molecule’s size and weight with the Zetasizer Nano ZS device has brought out exciting results and displayed similarities with the E4/E6 outcomes, only it’s tendencies proved to be informative because of its methodological background. &nbsp

The examination of humic substances in soils and composts with high organic content with different methods

The organic materials, especially the complex structural humic substances are acid-characteristic polymers which are key elements of soils. Despite their relatively small quantity, humic substances have beneficial effects on soil nutrient management, development of optimal soil structure, regulation of soil temperature, and proper water management. The application of the UV-VIS spectrophotometry for describing humic substances in soils and determining of humifical state is nowadays a widespread method. The E4/E6 procedure (which were determined between 465 and 665 nm wavelength) and the Hargitai-method (the extinction of extracts measured between 400 and 750 nm at 9 wavelength) are procedures that have become the general tool for determining the quality of humic matters because of its easy accessibility and smaller need of instrumentations. Nevertheless, their usefulness has been criticized in scientific communities because of the high human error factor and the technical limitations of the simpler spectrophotometric instruments. Nowadays the spreading light scattering photometric examinations using lasers as the Static Light Scattering (SLS) or the Dynamic Light Scattering (DLS) could be a new way of measuring the quality of the humic matters. This study is based on the examination of different quality soil and compost samples which were extracted from different Hungarian sites like Trizs, Szárítópuszta and Csobánc. Additionally, not only the soils and composts were analyzed but also any soil conditioners (biochar, bone charcoal) which were applied and affected their properties. The main goal of the research was to measure the soil and compost samples with the E4/E6 and the Hargitaimethod and with also using Zetasizer Nano ZS device that could lead to more detailed results about the weight and the size of the humic molecules. Based on the summarized analytic results the outcomes of the E4/E6 procedure is applicable for drawing relevant conclusion regarding the humic quality of the given sample. On the contrary, the applied Hargitaimethod has not proved to be effective. Although the measurement of the molecule’s size and weight with the Zetasizer Nano ZS device has brought out exciting results and displayed similarities with the E4/E6 outcomes, only it’s tendencies proved to be informative because of its methodological background

Talajminták lézeres szemcseanalízisének módszertani tapasztalatai

A lézerdiffrakciós szemcseanalízis egy korszerű módszer a talajmechanikai vizsgálatokban, ám egy egységes mérési szabvány bevezetése (akár műszerhez köthetően) nagymértékben növelné a mérések reprodukálhatóságát. A mérések tekintetében kiemelt szerepe van az előkészítő módszereknek (talajszerkezetet kialakító kötőanyagok roncsolása, elemi szemcsék diszpergálása), azonban ezen a téren is hiányzik az egységes szabványosítás. A tanulmányozott közlemények alapján megállapítható, hogy mind az optimális mintaelőkészítési módszer, mind pedig a legmegfelelőbb műszerbeállítás nagymértékben függ a mérni kívánt minta fizikai és kémiai sajátságaitól. A mérési eredmények hagyományos ülepítéses módszerrel kapott eredményekkel történő összehasonlítására szolgáló konverziós módszerek (frakció mérethatárváltások, illetve konverziós egyenletek) használhatósága is talajminta- és LDM vizsgálati módszer-függő. A lézeres szemcseanalízis alkalmazása a talajok aggregátum-stabilitás vizsgálata során ígéretes módszertani lehetőség, ám a mérések értelmezése és az összahasonlíthatóság megteremtése végett ezen a téren is elkerülhetetlen a szabványosítás. | Laser diffraction particle size analysis is an up-to-date method for use in soil analysis, but the introduction of a uniform measurement standard (possibly for specific instruments) would greatly increase the reproducibility of the measurements. Preparation methods (disintegration of the cementing agents ensuring the soil structure, dispersion of elementary particles) play an important role in this, but again no uniform standards have yet been compiled. Based on the papers reviewed in the present work it can be stated that both the optimum sample preparation method and the best instrument settings depend to a great extent on the physical and chemical properties of the soil to be measured. The suitability of the conversion methods used to compare the results with those obtained using conventional sedimentation methods (fraction size limit conversions, conversion equations) is also dependent on the soil sample and LDM technique. The use of laser diffraction particle size analysis for studying the aggregate stability of soils is a promising methodological option, but standardisation will be essential for the interpretation of the measurements and the achievement of comparability

A talajok mechanikai összetétel vizsgálata pipettás ülepítéses módszerrel: a hazai és a nemzetközi szabvány szerinti eljárások összehasonlítása és konverziója = Particle size distribution analysis using the pipet te method: comparison and conversion of Hungarian and internat ional standards

The particle size distribution (PSD) values obtained for a soil database representing the main Hungarian soil types using the Hungarian standard (MSZ-08-0205-78) and the international standard (ISO/DIS 11277:1994) were compared with the pipette method. The relationship between these PSDs and other physical soil characteristics (upper limit of plasticity according to Arany, water vapour adsorption according to Sík) was also analysed, and a suggestion was made of how these results could be converted into each other. Experience showed that the pre-treatments applied as part of the ISO/DIS method may change the ratio of particle size fractions: there was a significant increase in the clay content, while the silt content decreased to a lesser and the sand content to a greater extent, possibly because some of the particles remain in microaggregate form when the MSZ method is used. The results confirmed the greater accuracy of the ISO/DIS method: the clay contents measured with the ISO/DIS method exhibited stronger correlations with the upper limit of plasticity according to Arany and with hygroscopicity values than those measured with the MSZ method. The estimated ISO/DIS fractions became much closer to the measured ones when the suggested pedotransfer functions were applied. The conversion method proved to be more reliable for the prediction of clay and sand content than for silt content. In its present form the estimation method is not suitable for replacing the ISO/DIS method, but it could be of good service in research and comparative analysis in cases where only the MSZ method can be used or where only old MSZ PSD data exist

Evaluation of Soil Texture Determination Using Soil Fraction Data Resulting from Laser Diffraction Method

There are global aspirations to harmonize soil particle- size distribution data measured by the laser diffraction method and by traditional sedimentation techniques, e.g. sieve-pipette methods. The need has arisen therefore to build up a database, containing particle-size distribution values measured by the sieving and pipette method according to the Hungarian standard (sieve-pipette methods-MSZ) and the laser diffraction method according to a widespread and widely used procedure. In our current publication, 155 soil samples measured with sieve-pipette methods-MSZ and laser diffraction method (Malvern Mastersizer 2000, HydroG dispersion unit) were compared. Through the application of the usual size limits at the laser diffraction method, the clay fraction was under- and the silt fraction was overestimated compared to the sieve-pipette methods-MSZ results, and subsequently the soil texture classes were determined according to the results of both methods also differed significantly from each other. Based on our previous experience, the extension of the upper size limit of the clay fraction from 2 to 7 μm increases the comparability of sievepipette methods-MSZ and laser diffraction method, in this way the texture classes derived from the particle-size distributions were also more in accordance with each other. The difference between the results of the two kinds of particle-size distribution measurement methods could be further reduced with the pedotransfer functions presented