Effect of composting plant material with copolyester on quality of organic matter

The problem of incorporating plastics into the environment will be aggravating, both regarding its scale and kind of these materials. Investigations were carried out using aliphatic-aromatic copolyester poly (succinate-co-glutarate-co-adipate-co-terephthalate 1,4-butylene) with addition of fatty acid dimers. The work aimed to determine the effect of composting the copolyester with plant biomass on changes of fractional composition of humus substances and their stability. Copolyester was supplemented to the biomass in the form of a nonwoven fabric in two doses. It constituted 8 and 16% of the dry mass of the composted substrates. The composting process was run within two ranges of ambient temperature 25-30°C and 40-45°C. After the completion of this process, the degree of material maturing was assessed using manometric methods and the carbon content was analysed in the individual organic matter fractions. On the basis of cumulated respiratory activity AT4 a lack of composted material activity was revealed in the higher temperatures of the process. However, in the objects where copolyester was transformed in the lower temperatures this activity was considerably diversified. Adding copolyester to the composted biomass led to a diversification of the Cha : Cfa ratio. The values of Cha : Cfa ratio most approximating 1.5, ie the value regarded as optimal, were registered in the object, where copolyester supplement constituted 16% and the plant biomass was maintained within the 40-45°C temperature range.

Chemical characteristics of gypsy moth larvae excrement and their possible impact on soil properties in the total defoliation period

Chemical properties of gypsy moth larvae excrement were analysed with an objective to ascertain their possible impact on forest ecosystem nutrient cycling. The content of nutrition macro-elements in excrements was determined and compared to the content of nutrition macro-elements in oak leaves. The content of nitrogen mineral forms in excrements and group-fractional composition of humus were determined. It was established that during the total defoliation period there had been no loss of nutrient in the ecosystem. The properties of dropped and incorporated excrements are such that in the period of new leave formation after the total defoliation provide a sufficient amount of nutrients for forest trees.

Group fractional composition of humus of alluvial soils of floodplain of Western Bug River

Fractionally-group composition of humus alluvial turf, meadow, meadow marsh and bog soils of floodplain of Western Bug River was characterized. The results of studies of quality of soil humus of floodplain of this river by Ukrainian and foreign researchers were analyzed. The main indicators of fractionally-group composition of humus soils were studied. Key words: alluvial soils, humus of soil, fractionally-group composition of humus, humic acids, fulvic acids.

Effect of land use on group and fractional composition of humus in rendzina soils in Serbia

The effect of land use on group and fractional composition of humus was examined in 13 rendzina profiles under forests, 12 profiles under grassland and 8 profiles under arable fields in different parts of Serbia where rendzinas are typically found. The difference regarding land use of rendzina soils (depending on cultural practices or absence of any, and different amounts and quality of plant residues) under forest, grassland or arable fields had a highly significant statistical effect on humus group composition and the fractional composition of humic and fulvic acids. Human activities have brought about some positive changes regarding humus composition by promoting its stable component in rendzinas under grassland and arable fields, which is not the case in forest rendzina. The conversion of forests into grasslands and arable fields did not significantly affect the type of humus in rendzina soils, which remained characteristic of that soil type.

Fractionation of humus and optical properties of humic acids originating from different soil types

Assesment of soil organic matter quality is one of the urgent problems of contemporary agriculture. Determination of humic acids (HAs) optical properties using spectroscopic techniques could be a reliable step for this evaluation. We followed differences in the functional groups of HAs preparations and showed correlation between optical indexes and fractional composition of humus. UV-VIS and SFS spectral lines and indexes were measured in mixture 0.1M pyrophosphate sodium solution and 0,1M NaOH, after filtration and appropriate dilution. Differences in the structural composition of HAs originating from different soil types were studied after isolation of HAs preparations using FTIR spectroscopy (KBr + HAs pellets, SRATR FTIR method). Results showed that studied HAs preparations could be divided into two groups. First group included HAs isolated from Chernozem and Haplic Luvisol with higher content of aromatic constituents and condensation degree. The second group were HAs isolated from Eutric Cambisol and Fluvi-Eutric Gleysol. They reflected lower content of aromatic compounds, lower condensation degree and more aliphatic structural groups in the HAs molecule. Linear correlation between fractional composition of humus and optical indexes (I501/I487, Q4/6) was found.