The agricultural use of peatlands, the stabilization of the substrate for building or road construction or for increasing the capacity of soil to support heavy machinery for industrial activities (peat and petroleum extraction), harvesting to provide peat for energy, and the growing media and initiation of chemical processes must be preceded by drainage. As a consequence of drainage, peat underwent an irreversible conversion into moorsh (secondary transformation of the peat). The object of the study was to investigate comparatively the organic matter composition and molecular structure of humic acids (HAs) in the raised bog, fen, and peat-moorsh soils developed in various compositions of botanical cover, peat-forming species, and oxic and anoxic conditions as a result of the oscillation of ground water during drainage as well as to evaluate the vulnerability of soil organic matter (SOM) to decomposition. Drainage was shown to be the principal factor causing the various chemical compositions and physicochemical properties of HAs. Large and significant differences in chemical composition of peat and the properties of HAs were found to be related to the degree of decomposition. The HAs from drained peatlands were less chemically mature. In contrast, the HAs from fen and raised bog were found to be more mature than that of the corresponding drained peatlands. The above findings showed the distinguishable structure of HAs within the soil profile created by the plant residue biodegradation and formed in both oxic and anoxic conditions. The analytical methods of thermal analysis together with the optical densities and paramagnetic behaviour are suitable and effective tools for studying structure–property relationships characterizing the origin and formation process of HAs in various environmental conditions.
Было проведено сравнительное исследование физических, химических и биохимических свойств акротелма (торфогенный горизонт) и катотелма (горизонт накопления торфа) участков с доминированием сфагновых и осоковых торфов в Западной Сибири. Концентрация общего азота прямо пропорциональна содержанию нитрат-ионов и ионов аммония, активности уреазы, объемной плотности, и обратно пропорционально отношению C/N, пористости и влажности в обоих рассматриваемых типах почв. Полученные результаты указывают на низкий уровень азотной трансформации и замедление процессов разложения органического вещества в сфагновых и осоковых типах почв. Исследование показало, что сфагновые торфа претерпевают значительные химические и биохимические трансформации (окисление, гидролиз, полимеризация) с аккумуляцией наиболее устойчивых соединений по сравнению с органическим веществом осоковых торфов.
We investigated the varying concentrations of bound amino acids in humic acids (HA) extracted from soils under both crop rotation and continuous cropping of rye. The experiment was created in 1957. Since then, winter rye had been grown continuously and also the sequence of the 7 yr rotation had been started: potato, spring barley, alfalfa, alfalfa, oil seed rape, winter rye, and winter rye. Soils were fertilized with NPK and manure. Continuous cropping of rye increased total acidity of soils and the contents of carboxylic and phenolic groups in HA. The total amounts of the bound amino acids in HA from soils under crop rotation were higher than from continuous cropping of rye. Fertilization with NPK increased the contents of bound amino acids more than manure. Neutral amino acids dominated in all samples of HA, and basic amino acids had the lowest concentrations. In both types of cultivation, glutamic acids, glycine, alanine, valine, and lysine dominated. The proline contents in HA from continuous rye cropping were higher than in HA from soils under crop rotation. The concentrations of β‐alanine and lysine were higher in HA from crop rotation indicating a higher microbial biomass since these compounds are typical constituents of bacteria cell walls.
Oxidation-reduction reactions play a key role in ecologically important biogeochemical processes in soil and influence soil chemical, biochemical, and biological properties. The objective of this study was to compare the effect of a forest island located on two kinds of soils on the concentrations of iron forms and peroxidase activity participating in oxidation-reduction processes. The investigations were carried out in the Agroecological Landscape Park in Turew (40 km south of Poznan, Western Polish Lowland, 16°45'E, 52°0rN). The subject of the study was a palace park, which can be considered as a forest island. Part of this forest island is located on mineral soil and another part on mineral-organic soil. Our results showed that the flow of groundwater was accompanied by an increase in peroxidase activity, total iron concentration, and Fe(II) and Fe(in) ions in the mineral soils in most periods of sampling. However, an increase of peroxidase activity and a decrease of total iron concentration and Fe(II) and Fe(III) ions accompanying the flow of groundwater were observed in the mineral-organic soils.
The content of bounded amino acids in six entomopathogenic fungi was identified and determined. Analyzing the elements characterizing the pathogenicity of individual species of fungi based on infectivity criteria, ranges of infected hosts, and the ability to induce epizootics, these can be ranked in the following order: Isaria farinosa, Isaria tenuipes, Isaria fumosorose, Lecanicillium lecanii, Conidiobolus coronatus, Isaria coleopterorum. These fungi represent two types of Hyphomycetales-Paecilomyces Bainier and Verticillium Nees ex Fr. and one type of Entomophtorales-Conidiobolus Brefeld. Our study indicates that there are significant quantitative and qualitative differences of bounded amino acids in the entomopathogenic fungal strains contained in the mycelium between high and low pathogenicity strains. The richest composition of bounded amino acids has been shown in the mycelium of the Isaria farinosa strain, which is one of the most commonly presented pathogenic fungi in this group with a very wide range of infected hosts and is the most frequently recorded in nature as an important factor limiting the population of insects.
The Typic Hapludalfs soils under two old shelterbelts (200 years old) Robinia pseudacacia and Crataegus monogyna, multi species of trees (young shelterbelt - 20 years old) and neighbouring cultivated fields were investigated. The function of shelterbelts of different age and plant composition in agricultural landscape and estimation of biochemical and chemical soil conditions for the decrease of greenhouse gases release from soil to the atmosphere was the aim of the research. In soils under shelterbelts were estimated activities of several enzymes participating in the oxidation-reduction processes, ferric and ferrous ions and the evolutions of gases like N2, N2O, CO2, and CH4. The soils under old shelterbelts characterized higher peroxidase activity than in young shelterbelt and adjoining cultivated fields. However, no significant differences were observed for nitrate reductase activity between old and young shelterbelts. There were proved differences between emission of N2O in soils under shelterbelts and in adjoining cultivated fields. Furthermore, it was observed significant effect of the young shelterbelt on the decrease of carbon dioxide release than in the adjoining cultivated field. The manipulation of the landscape through the introduction of shelterbelts of different age and the composition of plants leads to the modification of biogeochemical soil conditions for N2O and N2 formation and finally decrease of the greenhouse gases evolution from soils to the atmosphere. Thus the creation of new shelterbelts is favourable factor for agricultural landscape.
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