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Clear-cutting induces biogeochemical, ecological, and hydrological changes in the soil environment, especially in the conditions of climate change effect. This type of management affects soil carbon sequestration. In this paper, we generalize the effect of clear-cutting in mountainous mixed coniferous forests on the direction of organic matter transformation and the properties of humic substances. Soil samples of dystric Cambisols were taken two and ten years after clear-cutting (CC). Soil profiles located at the same elevation under forest cover without any harvesting were used as references. The contents of total organic carbon, total nitrogen, qualitative and quantitative characteristics of humic substances, as well as the mineralogical composition and the clay-associated C fraction, were analysed. Under mountainous conditions, clear-cutting in the mixed coniferous forest enhanced organic matter decomposition and decreased the low-molecular weight humic fraction. It also caused the accumulation of more stable humic acids, particularly in the upper soil horizons, and resulted in accumulation of humic substances with higher contents of C and O and lower H content in the first years after CC. Clear-cutting in the first two years reduced the aliphacity of humic acids in the topsoil. Ten years after harvesting, a significant increase in aliphacity in the Oa horizon confirmed organic matter recovery. Mixed coniferous forests are more resistant to biotic and abiotic disturbances, which is particularly important in the face of violent weather phenomena related to climate change. Thus, forest management plans should consider the conversion of spruce monocultures to mixed coniferous forests. [ABSTRACT FROM AUTHOR]

The constant influx of pesticides into soils is a key environmental issue in terms of their potential retention in the soil, thus reducing their negative impact on the environment. Soil organic matter (SOM) is an important factor influencing the environmental fate of these substances. Therefore, the aim of this research was to assess the chemical behavior of pesticides (flufenacet, pendimethalin, α-cypermethrin, metazachlor, acetamiprid) toward stable soil humin fractions (HNs) as a main factor affecting the formation of non-extractable residues of agrochemicals in soil. This research was conducted as a batch experiment according to OECD Guideline 106. For this purpose, HNs were isolated from eight soils with different physicochemical properties (clay content = 16–47%, pHKCl = 5.6–7.7, TOC = 13.3–49.7 g·kg−1, TN = 1.06–2.90 g·kg−1, TOC/TN = 11.4–13.7) to reflect the various processes of their formation. The extraction was carried out through the sequential separation of humic acids with 0.1 M NaOH, and then the digestion of the remaining mineral fraction with 10% HF/HCl. The pesticide concentrations were detected using GC-MS/MS. The pesticides were characterized based on the different sorption rates to HNs, according to the overall trend: metazachlor (95% of absorbed compound) > acetamiprid (94% of absorbed compound) > cypermethrin (63% of partitioning compound) > flufenacet (39% of partitioning compound) > pendimethalin (28% of partitioning compound). Cypermethrin and metazachlor exhibited the highest saturation dynamic, while the other agrochemicals were much more slowly attracted by the HNs. The obtained sorption kinetic data were congruous to the pseudo-first-order and pseudo-second-order models related to the surface adsorption and interparticle diffusion isotherm. The conducted research showed that the processes of pesticide sorption, apart from physicochemical phenomena, are also affected by the properties of the pollutants themselves (polarity, KOC) and the soil properties (SOM content, clay content, and pHKCl). [ABSTRACT FROM AUTHOR]

Lignite burning is still the main source of energy in many countries, generating huge amounts of alkaline residues deposited in dumping sites, which affects the surrounding environment. There are only a few publications dealing with the effects on pH changes of surface horizons, but there are no reports on the impact on other soil properties. The aim of this paper was to characterize the changes occurring in the soil organic matter (SOM) of ectohumus horizons of Podzols located near the dumping site and at the control site. Conventional one‐dimensional, synchronous, and three‐dimensional fluorescence can provided a new information on differences in the structure of humic substances (HS), which are crucial constituents of SOM. Humic acid (HA) and fulvic acid (FA), originally present in the ectohumus horizon, indicated a lower degree of humification, and were characterized by a looser structure, than HS that were extracted from soils affected by fly‐ash. The neutralization of the soil reaction resulting from the deposition of fly‐ash favored the formation of higher humified HS, characterized by a higher concentration of aromatic rings in the core of the molecule and the presence of double conjugated bonds. The fluorescence technique could be applicable to monitor the chemical modification of soils in regions affected by ashes but also all factors changing soil pH. The conducted research has shown that fluorescence spectroscopy can be successfully used as a sensitive technique to characterize qualitatively structures of different organic substances present in terrestrial and aquatic systems. [ABSTRACT FROM AUTHOR]

Highlights: [•] The effect of MSW composts on soil properties, nitrogen availability to plants and its uptake efficiency was investigated in the field experiment. [•] High doses of MSW compost increased triticale yield similarly to NPK mineral fertilisation. [•] The shortage of the plant-available N was the main factor limiting the residual effect of MSW compost. [•] The efficiency of MSW compost originated nitrogen uptake by triticale was very low. [•] In sandy soil MSW compost was intensively mineralised contributing to N loss. [ABSTRACT FROM AUTHOR]