Tag Archives: peat

xxx M. Klavins, K. Upska, A. Viksna, M. Bertins, L. Ansone-Bertina and J. Krumins
A comparative study of the properties of industrially produced humic substances
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A comparative study of the properties of industrially produced humic substances

M. Klavins¹*, K. Upska¹², A. Viksna², M. Bertins², L. Ansone-Bertina¹ and J. Krumins¹

¹University of Latvia, Department of Environmental Science, 19 Raina Blvd, LV-1586 Riga, Latvia
²University of Latvia, Department of Analytical Chemistry, 19 Raina Blvd, LV-1586 Riga, Latvia
*Correspondence: maris.klavins@lu.lv

Abstract:

Humic substances (HSs) are produced industrially in large quantities from low rank coal, weathered coal, peat, also from soils, composts and other sources. Considering that the applications of industrially produced HSs also include food, pharmaceutical applications and environmental technologies, it is important to evaluate their composition and quality and to identify their sources. The aim of the present study is to compare the properties of industrially produced HS samples. HSs were characterised using spectroscopic and other methods. For the identification of origin of HSs, different methods can be used, such as elemental analysis and ratios of light stable isotopes. The results of the study indicate that many industrially produced HSs are of poor quality (low concentration of basic substance, admixture of undesirable substances, pollutants, no quality indications). In this situation, rigorous quality control should be implemented, providing detailed characteristics of the product. The composition of materials suggested for agricultural applications has not been analysed much. Most of the studied materials were designated as HAs, followed by fulvic acids (FAs) and HSs. However, an analysis of the humic matter types indicates that the majority of substances offered on the market are in fact mixtures of HAs and FAs; so, it would be more appropriate to designate them as HSs or their salts. This study identifies the main quality problems of industrially produced humic substances: 1) lack of strict quality indicators, 2) absence of indication of source materials/origins of HSs.

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228–240 V. Ozols, I. Silamikele, L. Kalnina, D. Porshnov, L. Arbidans, J. Krumins and M. Klavins
What happens to peat during bog fires? Thermal transformation processes of peat organic matter
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What happens to peat during bog fires? Thermal transformation processes of peat organic matter

V. Ozols, I. Silamikele, L. Kalnina, D. Porshnov, L. Arbidans, J. Krumins and M. Klavins*

University of Latvia, Faculty of Geography and Earth Sciences, Department of Environmental Sciences, Raina blvd. 19, LV 1586 Riga, Latvia
*Correspondence: maris.klavins@lu.lv

Abstract:

Bog fires are a serious natural phenomena. Major increase in the number of fires has happened during the last decades due to bog transformation into agricultural lands, accidents and human activities. During bog fires the peat is exposed to high temperatures due to which chemical transformation and even mineralisation of peat can occur. The aim of the study was to analyse the impacts of the bog fires on the bog as an ecosystem, advance the understanding and knowledge of fire impact on peat and humic matter properties and application possibilities. As the material for the study peat samples from burnt sites and thermally treated peat were used. To reveal peat transformation during bog fires, thermogravimetric analysis of peat samples were done, where amounts of bitumens, humic acids and mineral matter were estimated. During bog fires thermal modification of peat properties takes place, resulting in full mineralisation of peat and release of mineral substances. Bog fires lead to development of peat char, bitumens and significant changes in structure and properties of peat humic acids. However, from perspective of application of peat as a substrate and from perspective of impacts on the bog ecosystems, the effects are negligible.

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499-508 M. Klavins, O. Purmalis, S. Grandovska and L. Klavina
Properties of soil and peat humic substances from Latvia
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Properties of soil and peat humic substances from Latvia

M. Klavins*, O. Purmalis, S. Grandovska and L. Klavina

University of Latvia, Department of Environmental Science, Raiņa bulv. 19, LV 1586 Riga, Latvia
*Correspondence: maris.klavins@lu.lv

Abstract:

The acidity, elemental, functional and spectral (UV, fluorescence, IR spectra) characteristics of humic substances isolated from soils of different origin and peat in Latvia are described and compared with values common for humic substances of different origin, to evaluate the character of processes during humification. Substantial dependence of properties of humic substances on the humification conditions are found.

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759-768 T. Albert, K. Karp, M. Starast and T. Paal
The effect of mulching and pruning on the vegetative growth and yield of the half-high blueberry
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The effect of mulching and pruning on the vegetative growth and yield of the half-high blueberry

T. Albert¹, K. Karp¹, M. Starast¹ and T. Paal²

¹Estonian University of Life Sciences, Institute of Agricultural and Environmental
Sciences , Kreutzwaldi 1A, 51014 Tartu, Estonia
²Estonian University of Life Sciences, Institute of Forestry and Rural Engineering,
Kreutzwaldi 1A, 51014 Tartu, Estonia, e- mail: tairi.albert@emu.ee

Abstract:

The aim of this research was to determine the influence of different mulches (peat, sawdust, plastic) and different pruning methods (moderate, severe) on the growth and yield of the half–high blueberry (Vaccinium corymbosum x Vaccinium angustifolium) ´Northblue´. The effect of a mixture of soil and peat was studied in the case of peat alone and peat and plastic mulches. The experiment was established in 1996 in South Estonia and in 2002 blueberry bushes were pruned. The results of the study showed that mulching significantly influenced nutrient content and pH. Depending on the mulch, the soil pH ranged from 4.5 to 6.1 – there was more acid soil in the peat treatment. The use of mulches had some influence on productivity of pruned half-high blueberry plants. When peat was applied a canopy of pruned plants recovered very well after one year. Within three years the plants had the same yield as un-pruned variants but four years after pruning the yield was highest in the variants where peat was applied. Plastic mulch is not suitable for blueberries: it decreases the yield and four years after pruning the normal plant growth in our study had not recovered. Severe pruning is more suitable for half-high blueberry fruiting plants in northern climate conditions.

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149-160 G. Sokolov L. Szajdak and I. Simakina
Changes in the structure of nitrogen-containing compounds of peat-, sapropel-, and brown coal-based organic fertilizers
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Changes in the structure of nitrogen-containing compounds of peat-, sapropel-, and brown coal-based organic fertilizers

G. Sokolov¹ L. Szajdak² and I. Simakina¹

¹Institute for Problems of Natural Resources Use and Ecology, National Academy of Sciencesof Belarus, Skarina str. 10, 220114 Minsk, Belarus; email: agrico@ns.ecology.ac.by
²Research Centre for Agricultural and Forest Environment of the Polish Academy of Sciences,ul. Bukowska 19, 60-809 Poznań; email: szajlech@man.poznan.pl.

Abstract:

The three-stage acidic hydrolysis method was used for the degradation of three organic fertilizers prepared on the basis of peat, sapropel and brown coal. This method of hydrolysis may simulate the processes that occur in the natural environment, influenced by chemical and biological factors with a high degree of reliability, by taking substances from fractions depending on stability of compounds in the investigated organic materials. The investigation of changes in the content of nitrogen in the studied fractions allows judging the character and the degree of transformation of nitrogen-containing compounds in kaustobioliths organic substances and prepared fertilizers. In these three organic fertilizers the content of readily (“easy”) hydrolysable nitrogen ranged from 49.1 to 58.4%, the content of hard-to- hydrolyse nitrogen ranged from 4.6 to 19.5%, in unhydrolysable rest, content ranged from 31.6 to 37%. The results showed a significant supply of nitrogen included in amino acid structures in soils. Amino acids represent a form of organic nitrogen, readily hydrolysable by chemicals and enzymes, available for plants and soil microorganisms. The highest supply was observed for the fertilizer prepared on the basis of brown coal. This fertilizer supplied 93.7 % more nitrogen than the reference soil. Two other fertilizers prepared on the basis of peat and sapropel supplied 64.1 % and 56.3 %, respectively more than reference soil. A relationship and good correlation were found between the contents of readily (“easy”) hydrolysable forms of nitrogen and the total amount of amino acids, and also between the contents of readily hydrolysable forms of nitrogen and concentrations of nitrogen in amino acid structures.

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