Volume 25 (2022): Edizione 2 (November 2022)

The historical contribution of agriculture to human-induced climate change is indisputable; the removal of natural vegetation and soil cultivation to feed the growing human population has resulted in a substantial carbon transfer to the atmosphere. While maintaining their food production capacity, soft fruit production systems now have an opportunity to utilise a recent technology change to enhance their carbon sequestration capacity. We use an example of a farm in South-East England to illustrate how the soft fruit crop production system can be optimised for carbon storage. We performed an audit of carbon stocks in the soil and tree biomass and show that it is imperative to plan crop rotation to establish (semi) permanent inter-row strips that will remain in situ even if the main crop is replaced. These strips should be covered with grassland vegetation, preferable with deeper rooting grass species mixed with species supporting nitrogen fixation. Finally, grassland mowing cuttings should be left in situ and hedgerows and tree windbreaks should be expanded across the farm. Modern soft fruit production systems can enhance their carbon storage while maintaining commercially relevant levels of productivity.

Application of different types of feedstocks and conditions of their pyrolysis can result in different properties and sustainability of biochar during changes (aging) of its properties in soils. The aim of the studies was to assess the consequences of aging of biochar in soil for a content of adsorbed film water and a density of oxygen-containing functional groups on its surface. Sampling of soil and biochar was conducted in May and July of 2021 in a plot experiment with an applied rate of biochar of 20 t.ha⁻¹ in 2016. WP4-T dew point potentiometer was used for measurements of relationships of potentials of adsorbed film water and its content in soil and biochar. Infrared Fourier FSM 2201/2202 spectrometer was applied for determination of densities of oxygen-containing functional groups on surface of biochar in a mid-infrared spectrum. Results showed that retention capacity of adsorbed film water by soil increased from May to July, possibly because of increasing content of hydrophilic organic compounds of plant origin. Aging of biochar in soil also resulted in an increase of retention capacity of adsorbed film water on its surface. The results of infrared Fourier spectroscopy confirmed that densities of oxygen-containing functional groups on the surface of biochar increased from May to July at spectra of wavenumbers of 1,600–1,400 cm⁻¹ and 1,400–1,100 cm⁻¹.

Biochar application to agriculture soil has been recommended as a strategy to reduce increasing CO₂ emission in the atmosphere and mitigate climate change. In this study, we evaluated the impact of two doses of biochar (10 and 20 t.ha⁻¹) applied in 2014 and reapplied in 2018 combined with three fertilization levels (N0, N1, N2) on carbon dioxide emissions and selected physical and chemical soil properties in field conditions during spring season (April–June) in 2020. The field site is situated in the Nitra region of Slovakia (Malanta). The soil in the field was classified as a silt loam Haplic Luvisol. In this field research it was found that biochar application mostly in all treatments decreased cumulative CO₂ emissions in rage from 4.2% to 30.4% compared to controls (B0N0, B0N2), except treatments where biochar was applied with lower level of N-fertilizer (N1) and treatment B20N0. According to our study results, it was confirmed that biochar can be a promising material for improving soil physical and chemical properties. Mainly, it has very good impact on soil pH, even after seven years of field experiment established. However, the response of soil CO₂ fluxes to biochar application were regulated mainly by experiment length, biochar application rate, biochar properties, giving a new perspective for more comprehensive understanding on biochar.

The engineered multi-layered cover system (MLCS) is used to minimize rainwater infiltration into the wastes accommodated in near surface waste disposal facility (NSDF). It is important to assess the hydraulic performance of MLCS before deploying it in the field. For this purpose, an instrumented three-layered soil column representing MLCS was subjected to 1.5 m constant ponding head for 400 days. The variation of volumetric water content and soil water potential was monitored as a function of depth and time. The objective of the study is to understand the long-term hydraulic performance and rate of saturation of different layers of MLCS. Under constant water ponding, the time to saturation for 0.3 m in surface layer, 0.6 m in drainage layer and 1.0 m in hydraulic barrier layer was observed as 24, 223 and 262 days, respectively. The numerical analysis of the MLCS predicted comparable time duration of 25, 234 and 272 days, respectively. It was noted that the numerical simulation performed by using measured wetting hydraulic parameters matched well with the experimental observation. The importance of soil specific calibration of water content sensors to improve the accuracy of observations was demonstrated. Percentage error in the estimation of layer specific soil water storage, clearly indicates that the volumetric water content measurements using profile probe was marginally better than 5TM measurements.

This paper shortly introduces the topic of soil microplastics by presenting a comprehensive review of the current state of the art in this field. It focuses mainly on the role of primary microplastics, particularly glitters, due to their large surface-to-volume ratio. From conclusions about current challenges and research directions, after analysis of the crucial “knowledge gaps “, one can point out the lack of a detailed description of the influence of microplastics on biota. The earthworms are promising model organisms that may play in soil ecosystems a similar role to the bivalves in waters. Thus, this mainly review paper was enlarged by the preliminary results of studies on glitters and bioglitters naturally aged in milli-Q water and soil with Eisenia fetida. Fourier-transform Infrared (FTIR, microscopy in the reflectance mode) and Raman spectroscopy (780 nm) were used to identify the subsequent notable changes in studied materials. The presence of the polymer (PET) core in the standard glitter particles is confirmed. In addition, the leakage of dyes from bioglitters was observed within the 9-week experiment. Tested bioglitters decompose in a slightly different way. Blue and pink pigments had entirely different stability as only one disappeared without a trace under UV light (blu), and the other remained stable in solution, confirmed by UV-Vis spectra. The nephelometry shows sedimentation of glitters after turbulent agents in the environment. This paper presents the natural weathering of primary microplastics in the presence of Eisenia fetida.

Natural conditions highly predict further use of the locality. Current climate change, population growth and other crises open questions of better use and design of existing and new irrigation systems. Government of Uzbekistan currently highly invest in the water-saving irrigation systems which should correspond to natural conditions of the locality. Therefore, deep study of each area of interest is necessary. Based on the available information of natural conditions of Uzbekistan, the crop production localities overlap localities with low precipitation, high temperature rise in last years and middle groundwater level. Also, part of them lays on the soils with low water holding capacity and high salinity. Especially in those areas the proper design should be done.

Pyrolysis of feedstocks to produce biochar for soil remediation employed to be a convenient method regarding improvement of soil fertility, increasing carbon stability and decreasing greenhouse gas emissions. Biochar properties and its effect after incorporation into the soils vary depending on the characteristics of feedstocks and pyrolysis process. This paper aims to compare the effect of pyrolysis temperature on the frequency of functional groups in different biochars made from plant feedstocks over the temperature range from 300 °C to 700 °C. An increase in pyrolysis temperature positively affects biochar surface properties until the deformation step in C = O, –COOH, and OH groups and as a result, the surface area of biochar decreases at high temperature (more than 600 °C). The breakdown of hemicellulose, cellulose, and lignin also occurs at temperatures more than 600 °C. Consequently, the biochar quality is reduced with increasing pyrolysis temperature although such biochar may be suitable for rising the content of stable carbon in the soils. Over the long-term, the stability of biochar can contribute to carbon sequestration, retention of water and ions in the soil.

Polycyclic aromatic hydrocarbons (PAHs) are prevalent environmental pollutants produced by incomplete combustion of biomass including fossil fuels, wood, and coal. The majority of PAHs in the environment emits from anthropogenic activities, while some are released from naturally occurring phenomena, such as volcanic activities. Consequently, PAHs concentration is significantly higher in industrialized and urban areas than in rural areas. Human exposure to PAHs results in many health problems, depending on the PAH concentration type, time and method of exposure, and individual health status. The PAHs readily transport between soil, water, and the atmosphere. Four main processes involved in PAH transportation are volatilization, absorption, leaching, and erosion. However, many factors affect PAHs‘ transportation, including PAHs‘ molecular weight, vapor pressure, soil matrix, climate condition, and topography. Various remediation techniques have experimented in order to PAHs remove from the natural environment. Bioremediation, in particular, is an optimistic way that can be done by bacteria, fungi, and alga.

Antioxidants are compounds that inhibit combustion (oxidation) processes. Antioxidants are vital components of our body, which can be obtained in part through plant nutrition. Therefore, it is very important to study species that have significantly higher antioxidant capacity than other species. The aim of the study was to investigate the antioxidant capacity of total polyphenols (TPC) of European mistletoe (Viscum album L.) leafy shoots collected from different species of trees (black locust, European ash, white poplar, field maple and black walnut) based on different methods; DPPH (2,2-diphenyl-1-picrylhydrazyl), FRAP (ferric reducing antioxidant power) and TPC (total phenolic contents). The results proved that the antioxidant effect of leafy shoots from European ash (Fraxinus excelsior) against hydroxyl radicals (ROS) showed significantly higher values than those of the other four tree species. We found that the DPPH, FRAP and TPC methods show significant differences in antioxidant effect of European white mistletoe leafy shoots on the studied tree species and tea brands. However, the FRAP method shows higher sensitivity for trees but for tea brands, the DPPH method is more sensitive. The reason for the difference might be explained by the different methods of drying. In the future, we consider it feasible to plant ash groves at an altitude of at least 80 m above sea level in a closed area, where we can start growing European white mistletoe as an herb. Based on the results obtained European white mistletoe can be recommended as an herb to natural medicine for supplementary treatment of several cancer diseases.

Celosia (Celosia argentea), is an important tropical vegetable for households in sub-Saharan Africa. Despite the multifaceted usefulness, available genotypes are low-yielding, and the vegetable faces dangers of genetic erosion due to poor research attention. The magnitude and pattern of variability will guide the choice of breeding methods for improvement. Twenty-one celosia accessions were evaluated in 2018 and 2019 to determine study genetic variability and heterotic patterns among clusters. Accessions and clusters differed significantly (p ≤0.05/0.01) for plant height, number of leaves/plant, stem weight, harvest index and dry matter content. Genotypic coefficients of variation; ranging from 37.89 to 0.12, were lower than phenotypic coefficients of variation which ranged from 114.55 to 0.12, both for number of leaves/plant and harvest index respectively, indicating the importance of environment in the variability. Discriminant analysis indicated low (8.12%) classification error rate, indicating the possibility of heterotic patterns among clusters. Principal component (PC) analysis controlled 73% of the observed variability among accessions and identified all measured traits as important contributors with loadings ranging from 0.30 (in PC 1) to 0.63 (in PC 2) for harvest index and stem weight respectively. Useful levels of association were also observed among measured traits. The study concluded that there was sufficient genetic variability for effective selection. Discriminant and principal component analyses identified plant height, number of leaves/plant and dry matter content as major contributors to variation among accessions. Weight of edible parts of Celosia can be simultaneously improved with plant height and number of leaves/plants.

Climate change is increasingly occurring not only in Slovakia and Europe, but worldwide. One of the consequences is frequent droughts alternating with extreme rainfall. Drought, especially in the spring months, causes water shortages in the soil and limited crop growth. Extreme rainfall causes frequent floods and destroys crops and property. The aim of this work was to statistically evaluate precipitation during January–December for the period 1921–2020 in the most fertile part of Slovakia – the Danube Lowland. The results show a statistically significant (p <0.10) decrease in precipitation in April and an increase in September, with the annual total precipitation from 535 to 600 mm (except for extremes in some years). The work provides a statistical analysis of changes and rainfall distributions over 100 years, which can help identify and address drought problems.