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Earthworms dominate the soil biota, and different structural and functional features of their biology and ecology have been studied and exploited to evaluate their contributions as ecosystem services. Due to their feeding ecology, burrowing and casting activity, earthworms are involved in the nutrient cycles, and therefore it is opportune to be considered when the biogeochemical cycles of the terrestrial ecosystems are analysed. All structural, microbiological and biogeochemical impacts of earthworms in soil start with their feeding and digestive functions, which end in casting. The casting activity consisting of the excretion of the ingested soil and organic matter after digestion processes depends on earthworm feeding behaviours and ecology, even described in the current literature as a new ecological feature: the casting ecology. The complexity of the chemical relationships occurring inside earthworm casts between main nutrients (organic carbon, nitrogen, phosphorus, potassium, calcium) highlights the complexity of the biogeochemical cycles and the great earthworms’ contribution to these cycles in the ecosystems towards a better understanding of the soil sustainability through the soil biodiversity contribution. Due to this great contribution, the earthworms’ casts should be included as indicators in the integrative conservation management of the ecosystems, as a re-thinking of the concept of ecosystem sustainability.

This study aimed at investigating the effect of ontogenetic and diurnal variability on yield and quality criteria of Mentha piperita. The research was conducted in the Ordu province of Turkey for two years. The trial was established in a randomised complete block design with 3 replications according to factorial regulations. Four different harvesting periods (budding, first flowering, 50% flowering, 100% flowering) and three harvesting hours (9:00 a.m., 1:00 p.m., 5:00 p.m.) were evaluated. A significant difference was determined between the trial years in all characters examined: plant height 55.9-69.0 cm, fresh herb yield 3 236-16 438 kg/ha, drug-herb yield 1 748-2 862 kg/ha, fresh leaf yield 3 477-4 506 kg/ha, drug leaf yield 968-1 253 kg/ha, essential oil ratio 2.0-2.5% and essential oil yield that varied between 19-28 L/ha. The highest yields were obtained at the beginning of flowering in drug leaf yield and 100% flowering period for all other characteristics. Diurnal variability was statistically significant only in the rate of essential oil, and the highest rate occurred in the 9:00 a.m. harvest.

Foliar nutrients containing macronutrients, micronutrients and a combination of both were applied to Physalis peruviana, P. alkekengi and P. ixocarpa to determine their effect on fruit quality. A randomised complete block design study was conducted in a greenhouse on Madura Island, Indonesia. This study showed significant interactions between Physalis species and foliar nutrition to the physicochemical character of the fruit. Each species responded differently to the given nutrients. The combination of 1 g/L macronutrient (P and K) and 0.0625 g/L micronutrients (Zn, Fe, Cu, B, Mo and Mn) resulted in the highest fruit antioxidant activity, vitamin C, total soluble solids and redness of the three Physalis species. Generally, macronutrients and micronutrients in combination can be recommended to increase the quality of Physalis fruit.

The honey bee is one of the insects that is significantly endangered by the application of pesticides in the cultivation of crops. Not only is acute toxicity dangerous, but the importance of chronic poisoning by low doses of pesticides in hives is growing. The behavior of bees can be affected not only by insecticide residues but also by herbicide and fungicide residues. In 2016-2018, samples of bee bread were analysed for pesticide content at 25 different localities from intensive agricultural production areas of the Czech Republic. Substances were extracted by QuEChERS and determined by liquid chromatography, together with mass spectrometric detection. We detected up to 18 pesticides in one sample. In total, during 2016-2018, we identified 53 active substances. Fifteen substances (31%) were herbicidal, 23 substances (47%) of fungicidal nature and 6 substances (12%) of insecticidal nature. The coefficient of variation showed large differences in the frequency of revealed pesticides between years. For substances sprayed outside period attractive for pollinators (mainly herbicides and some fungicides), the usual methodology cannot reliably determine the degree of contamination, and thus the actual contamination with these substances may be even higher than demonstrated in this study.

The ameliorative effects and its mitigation mechanisms of selenium (Se) on cadmium (Cd) toxicity in cucumber seedlings were studied through hydroponic experiments. Cd and other mineral nutrient concentrations, antioxidant enzyme activities, and antioxidant contents in cucumber were studied. The results revealed that exogenous Se significantly decreased the Cd concentrations in all tissues, especially in the leaves. Moreover, exogenous Se (Cd + Se) could increase Zn, Na, leaf Cu, stem/root Fe, stem/root Ca, and stem/root Mg concentrations; and reduce leaf Mg concentration, compared with Cd alone treatment. Additionally, the application of Se ameliorated the toxicity of Cd by harmonising the activities of antioxidase, such as Cd + Se treatment reduced Cd-induced increase of superoxide dismutase, glutathione peroxidase, leaf/stem ascorbate peroxidase (APX) activities, which resulted in the significant decrease of the content of hydrogen peroxide, and malondialdialdehyde; increased root APX, and glutathione reductase activities. In addition, the content of nonenzymatic antioxidants such as root-reduced glutathione and oxidised glutathione was significantly increased by adding Se under Cd stress. Also, exogenous Se enhanced the total antioxidant capacity in terms of cupric-reducing antioxidant capacity and decreased total phenols, flavonoids, and leaf/root proline contents under Cd stress. In general, 3 μmol/L Se was conducive to plant growth and improved the cucumber's ability to alleviate Cd stress.

This study compares the effect of application of digestate, straw, cattle slurry and inorganic fertilizers on crop yield and soil organic matter content. Total organic carbon (C), total organic nitrogen (N), hot water soluble C, microbial biomass C and hydrophobic soil components were evaluated in soil from the field experiment in Prague-Ruzyně (Orthic Luvisol, clay loam) with winter wheat. All fertilized treatments significantly increased grain yield above the level of non-fertilized control (5.68 t/ha), and the sequence was as follows: digestate (9.88 t/ha) > NPK(9.80 t/ha) > cattle slurry (9.73 t/ha) > digestate + straw (9.35 t/ha). Average organic C content in the soil ranged from 1.668-1.704% and the effect of different fertilization was not significant. The highest increase of microbial biomass C was recorded in digestate + straw (43.2% increase compared to control). Highly significant correlations were found between hydrophobic soil components and hot water soluble C (r = 0.988; P ≥ 0.05) and microbial biomass C (r = 0.964; P ≥ 0.05). Total organic N content ranged from 0.157-0.160% and differences among treatments were insignificant. Fertilization with digestate itself brings an effect in increasing crop yield, but does not improve the level of soil organic matter significantly.

Cultivating crops influences soil organic matter (SOM), but the effect of different crops remains unclear, particularly under long-term monocropping. The objective of this study was to identify how different crops influence the content and chemical structures of SOM under long-term monocropping. Here, soils were sampled (0-20 cm) under 27-year soybean and maize monocropping and separated into different physical fractions. The content and chemical structures of SOM in all fractions were determined. SOM contents were higher under soybean than maize in bulk soil and macroaggregates and their light-fractions instead of microaggregates and silt and clay. The difference in SOM chemical structure was observed in aggregates and density fractions rather than bulk soils and supported by the result of principal component analysis. The proportion of O-alkyl C in macro- and microaggregates and all free light fractions and that of aromatic C in mineral-associated fractions were higher, while that of carbonyl C was lower under maize than soybean. These results demonstrated that different crops monocropping influences the content and chemical structures of SOM, and the variations were mainly in the light-fraction SOM and highlight a higher sensitivity of physical fractions than bulk soil to different crops.

Diallyl disulfide (DADS) is an organosulfur compound that is expected to exhibit inhibitory property against urease similar to allicin, affirmed through preliminary study. The research aims to optimize DADS's concentration and duration of inhibition and observe the effect of soil moisture, temperature and pH on the inhibitory action of DADS. The calorimetric method was applied to optimize DADS's concentration significant for inhibition. High-performance liquid chromatography was used to quantify DADS present under different parameters relevant to selected soil conditions. The results obtained suggested that 5% of DADS/urea-N (w/w) treatment exhibited the highest urea hydrolysis reduction by 27.91% compared to the control sample at the end of 30 days. ANOVA results observed urea hydrolysis is significantly slower by applying 5% DADS/urea-N (w/w) treatment compared to the other DADS treatments. DADS also retained its original form longer in soil when the soil conditions were altered to 15% moisture content, 20 °C and pH 4. The findings exhibit the potential of DADS as a natural based inhibitor that is effective at low concentrations, compatible with urea and chemically stable.

To evaluate the long-term effects of fertilisation on soil organic carbon (SOC) sequestration in rice-wheat cropping ecosystems, SOC dynamics, stocks and fractionation were determined. The treatments included no fertiliser, mineral N and P, mineral N, P and K, organic fertiliser (OF), OF plus NP and OF plus NPK. The results showed that the average carbon inputs that derived from crop stubble, root residues and organic fertilisers were between 1.47 and 4.33 t/ha/year over the past 34 years. The average SOC stocks measured in the samples collected in 2011-2013 ranged from 31.20 to 38.52 t/ha. The range of the SOC sequestration rate was 0.11-0.40 t/ha/year with a SOC sequestration efficiency of 6.3%. Overall, organic fertilisation significantly promoted C-input, SOC and the sequestration rate compared to mineral fertilisation. The "active pool" (very labile and labile fractions) and "passive pool" (less labile and recalcitrant fractions) accounted for about 71.0% and 29.0% of the SOC fractions, respectively. Significant positive relationships between C-inputs and SOC fractions indicated that SOC was not saturated in this typical rice-wheat cropping system, and fertilisation, especially organic amendment, is an effective SOC strategy sequestration.

Potato (Solanum tuberosum L.) is a plant typical mainly for temperate climate and develops best at about 20°C. Heat stress due to increased temperatures is an agricultural problem in many areas in the world. The aim of our work was to assess the response of selected new potato cultivars to heat and drought stress during the subsequent stages of plant growth starting from buds forming. The pot experiment was carried out over the course of two years with the following early cultivars: Lord, Miłek, Gwiazda, Hubal, Oberon and Tetyda. The impact of heat (38°C/25°C) and drought stress on potato plants was tested in four periods of two weeks. In these periods half of the plants were watered to a level close to optimal while the other half remained without irrigation. Our studies demonstrated that tested potato cultivars' response to heat stress depends on the growth stage, in which the temperature acts on the plants and on the soil moisture. Besides the decrease in yield and tubers' diminution, the biggest problem was the presence of tubers with physiological defects, particularly of immature tubers. The response of cultivars was differentiated.

Atrazine is still widely used in China. Atrazine residue (1.86-1 100 mg/kg) in the soil has exceeded the allowable limit (1.0 mg/kg), affecting soil structure and soil aggregate composition. To understand the long-term application of atrazine on soil aggregates and the binding agent, four treatments were established in cornfield planted since 1998, including without atrazine applied (AT₀), atrazine applied (28% atrazine, 1 200-1 350 mL/ha/year) once a year from 2012 to 2018 (AT₆, 167 mg/kg), from 2008 to 2018 (AT₁₀, 127.64 mg/kg) as well as from 2002 to 2018 (AT₁₆, 102 mg/kg) with three replications. Along with the increase of atrazine application time, the mass fraction of soil aggregates > 5 mm and 2-5 mm decreased significantly while the mass fraction of soil aggregates 0.5-2 mm and < 0.5 mm increased gradually, and the change of aggregate binding agents contents were the same as that of aggregates. The contents of soil organic carbon (SOC) and glomalin-related soil protein (GRSP) in the aggregates > 5 mm and 2-5 mm were significantly negatively correlated with the years of atrazine application. Our results show that although atrazine residue in the soil does not increase with the increased yearly application, its concentration is still markedly higher than the permitted limit value and seriously affected the content of SOC and GRSP of aggregates > 2 mm, which can lead to a decrease of soil aggregate stability and soil quality.

The ability to adapt, survive, and compete with weeds of transgenic plants is the necessary evaluation content to release transgenic lines in target regions. We compared weediness and agronomic traits of transgenic maize lines G1F-8 and G1F-19 carrying the mcry1F gene with their near-isogenic maize inbred line Zheng 58 in the wasteland and cultivated field under natural conditions for two consecutive years. The results showed that there was no significant difference identified in the species, quantity, and relative coverage ratio (RCR) of weeds between fields with G1F-8, G1F-19, and Zheng 58, regardless of the sowing pattern in the wasteland. Compared with the vigour of weeds, none of G1F-8, G1F-19, and Zheng 58 showed survival advantages, and all showed weak growth potential with no final grain yield. Meanwhile, no volunteer seedlings were found upon investigation in the following year. The simulated seed overwintering experiment in the wasteland further showed that the three kinds of maize could not germinate in the second year. In cultivated land, G1F-8 and G1F-19 had the same growth stages, plant height, and RCR as Zheng 58 throughout two years. In conclusion, the transgenic lines G1F-8 and G1F-19 exhibited no adaptability risk in Gongzhuling, Jilin, China.

In potato tubers of four cultivars, the impact of drought and waterlogging stress on total carotenoid content (TCC) and individual carotenoids profile variance and total carotenoids, chlorophylls (a, b, a + b) content in leaves during period 71 days of stress in two-year pot greenhouse experiments were investigated. The different response between potato cultivars was observed after exposure to drought stress (an increase of TCC was in Marabel and Laura cultivars) and after waterlogging stress (in Milva and Marabel cultivars). On average, of all cultivars, both drought and waterlogging stresses caused total carotenoid content to increase with a higher impact of drought stress. In potato tubers, eight carotenoids were identified with the most represented violaxanthin, luteoxanthin, antheroxanthin and lutein. Significant differences in individual carotenoid amounts between cultivars have been determined. On average, drought and waterlogging stresses of all cultivars significantly increased contents of violaxanthin, 9'-(Z)-neoxanthin and luteoxanthin, while antheraxanthin, lutein and zeaxanthin levels decreased. In leaves, both abiotic stresses decreased chlorophyll contents (a, b, a + b) with a very destructive impact of drought stress. While carotenoids accumulated in tubers as a result of stress, the opposite trend was characteristic in leaves, where their content decreased depending on the duration of stress.

One of the latest environmentally friendly methods in soybean production technology is the pulsed electromagnetic field of low frequencies (PEMP). The paper presents the results of the influence of electromagnetic stimulation of soybean seeds on grain yield, protein and oil yield, depending on different agroclimatic conditions, exposure time and frequency. In the 2012–2017 research period, the soybean cv. Valjevka was used in the Institute of Field and Vegetable Agriculture experimental field, Novi Sad, Serbia. Immediately before sowing, the seeds were subjected to PEMP treatment, with a pulse generator and a tape applicator, in the following variants: electromagnetic field frequencies of 16, 24 and 30 Hz, and exposure time of 0, 30 and 60 min. The most successful variant of seed stimulation for all three examined parameters was at 16 Hz and 30 min, where the research results show that this measure can increase the examined parameters by more than 10%. The average yield of grain for all years of research with seed stimulation was 4.85% (3 338 kg/ha) compared to the control (3 203 kg/ha). The average grain protein yield in the treatments with PEMP was 1 315 kg/ha, which was 4.26% higher compared to the variant without PEMP (1 260 kg/ha), and the treatment was 4% higher in the average oil yield, 703 kg/ha compared to the control 676 kg/ha. Also, the analysis of the mutual dependence of the indicators is in a positive correlation, which is essential for plant breeding and the development of new technologies, which have economic justification, are safe for use and have a positive impact on adverse effects such as drought.

Zinc (Zn) insufficiency and water deficiency are primary challenges in intensive rice production systems. This study aims to examine the influence of two irrigation regimes, flood irrigation (FI) and water-saving irrigation (WSI), on rice grain yield and mobile Zn accumulation in soil and rice grains. Experiments were conducted in An Vien rice fields in the Tien Lu district, Hung Yen province, located in the middle of the Red River delta during four rice seasons from 2015 to 2016. The results showed that the WSI regime dramatically increased the grain yield and Zn concentrations in grain of rice. Grain yield was increased by 14.76% and grain Zn concentration by 17.93% when compared with the FI regime. The decrease in the mobile Zn concentration in soil was only 5.7% in the WSI technique, compared with 73.6% for FI techniques. Therefore, it can be concluded that WSI can be effective agricultural practice to elevate grain yield and increase Zn retention in soil and bioavailability in rice grains.

A three-year experiment was conducted to investigate the effect of Z'Fix on soil physical properties and crop status. Z'Fix is an agent recommended as an addition to animal bedding to prolong its function and to lower ammonia emissions in stables. Concurrently, a positive effect on organic matter transformation in resulting manure is claimed. The experiment involved control, farmyard manure (FYM), and farmyard manure with Z'Fix (FYM_ZF) as variants. In-field sampling was conducted for cone index, water infiltration and implement a unit draft, where the latter two showed significant differences in favour of FYM_ZF. Also, concerning crop yields, FYM_ZF consistently attained the highest values, followed by FYM throughout all three seasons. Furthermore, remotely sensed data were analysed to describe crop status via normalised difference vegetation index where significant differences were found across all variants. Based on the study, FYM_ZF demonstrated positive effects both on soil properties and crop conditions.

Glyphosate is a widely used agrochemical. Nevertheless, only a few studies have investigated its effect on bees, specifically its influence on their foraging activity. This article provides a summary of the prominent research results on this issue, published in journals in the field of experimental biology. The effect of commonly used concentrations of glyphosate on honey bee navigation has been evaluated in several studies, as well as concentrations that are reportedly sublethal. Exposure to this herbicide increases the flight time back to the hive and affects the flight trajectories of these bees. These results imply that glyphosate at certain concentrations reduces their sensitivity to nectar rewards in associative memories. The contact of bees with non-lethal concentrations of glyphosate results in sublethal effects that affect foraging. In the future, the behaviour of glyphosate and its effect on bees in their natural environment need to be explored.

Although various studies of codon usage bias have been reported in a broad spectrum of organisms, no studies to date have examined codon usage bias for herbicide target genes. In this study, we analysed codon usage patterns for the acetolactate synthase (ALS) gene in eight monocot weeds and one model monocot. The base composition at the third codon position follows C3 > G3 > T3 > A3. The values of the effective number of codons (ENC or Nc) indicate low bias, and ENC or Nc vs. GC3 plot suggests that this low bias is due to mutational pressure. Low codon adaptation index and codon bias index values further supported the phenomenon of low bias. Additionally, the optimal codons, along with over- and under-represented codons, were identified. Gene design using optimal codons rather than overall abundant codons produce improved protein expression results. Our results can be used for further studies, including eliciting the mechanisms of herbicide resistance (occurring due to elevation of gene expression levels) and the development of new compounds, their efficiency and risk assessment for herbicide resistance evolution.

The aim of the study was to assess soybean response to sowing material inoculation with HiStick® Soy preparation, containing Bradyrhizobium japonicum. Based on the obtained results, it was found that the inoculation significantly increased the number and dry weight of nodules on soybean roots compared to control. The bacterial preparation significantly increased the number of pods per plant. As a result, a significant increase in seed yield (0.58 t/ha) was obtained compared to control. HiStick® Soy increased total protein content in seeds. Protein and fat yield was higher after seed inoculation by 318 kg/ha and 101 kg/ha, respectively, compared to control.

Drought stress is a major environmental factor limiting crop growth and productivity. Hydrogen peroxide (H₂O₂) plays an essential role during stress response by acting as a signal molecule that activates multiple stress tolerance mechanisms. In this study, the effects of H₂O₂ on agronomic traits were studied in rice (Oryza sativa L.) cv. Khao Dawk Mali 105 (KDML 105) was subjected to drought stress. H₂O₂ was applied by either seed priming or foliar application method with a concentration of 1, 5, and 15 mmol/L. The results showed that both seed priming and foliar application with H₂O₂ improved some yield components. The tiller numbers, number of panicles, number of filled grains, filled grain weight, and harvest index were improved approximately 1.13, 1.04, 1.23, 1.21, and 1.1 times compared to the untreated plants. Foliar application, however, helps the plant by reducing yield loss as indicated by a 0.5-time reduction in the number of unfilled grain and lower unfilled grain weight. It was suggested that 5 mmol/L H₂O₂ was the most effective concentration to alleviate the effect of drought stress during the reproductive stage in rice.

Research was conducted to determine the content of total polyphenols (TP) in table potato tubers obtained in a three-year field experiment arranged as a split-plot design with three replicates. The first experimental factor included two potato cultivars: Oberon and Malaga, the second one being an application of the following biostimulants: PlonoStart, Aminoplant, Agro-Sorb Folium and the herbicide Avatar 293 ZC (clomazone + metribuzin). The polyphenol content of potato tubers was determined in the fresh tuber mass by the spectrophotometric method with the Folin-Ciocalteu reagent. The tuber content of polyphenols was affected by cultivars and test biostimulants. Cv. Malaga accumulated more polyphenols than cv. Oberon. Biostimulants + herbicide significantly increased an accumulation of polyphenolic compounds compared with tubers cultivated in the control unit which was not treated with the test products.

Small field plot experiments were carried out at the testing station of the Central Control and Testing Institute in Agriculture in Veľký Meder (Slovakia) in the experimental years 2014/2015, 2015/2016 and 2016/2017. Selenium salts in the form of sodium selenite and sodium selenate were applied in growth phases: end of tillering (BBCH 29) and flag leaf ligule and collar visible (BBCH 39). The effect of experimental years 2014/2015, 2015/2016 and 2016/2017 on the yield of wheat grain was not statistically significant within the observed variants. The achieved mean yields were in the range from 10.06 ± 0.81 to 11.07 ± 0.29 t/ha in 2014/2015, from 9.82 ± 0.54 to 10.32 ± 0.10 t/hain 2015/2016 and from 11.23 ± 0.76 to 11.64 ± 0.51 t/ha in 2016/2017. Selenate in comparison with selenite influenced the selenium accumulation in wheat grains more positively. However, a significant difference was recorded in variants with selenite application in the flag leaf growth phase in comparison with the end of tillering phase. The influence on the content of macroelements P, K, Ca and microelements Cu and Fe was observed in sodium selenite only; its application decreased the element content in comparison with the control variant. Statistically significantly higher values of fiber and fat were achieved after application of selenium in the flag leaf growth stage in comparison with the end of tillering.

Biochar is a carbonaceous material derived from the pyrolysis of carbon-rich biomass that has attracted increasing research and attention because of its ability to enhance soil carbon storage, increase soil fertility, fix and transform pollutants in soil, and improve the soil environment. These enhancements directly or indirectly affect soil microorganisms’ metabolic activities and community structure. This paper reviews the effects of biochar on soil physicochemical properties, enzyme activities, nutrients, contaminants, and related microbial activities. In addition, this work summarises the possible mechanisms involved in the interaction between biochar and microorganisms and the potential hazards associated with biochar use. Finally, this study aims to provide a theoretical basis for future related research.

Insect pollination is one of the most important ecosystem services. Pollinator communities are rarely studied across years and crops in the same location. The aim of this study was to investigate the pollinator community structure on five different fruit crops, as well as the activity of different pollinator groups during the day and their temperature preferences. Pollinator activity was observed across two years on apple trees and blueberry, strawberry, blackcurrant and raspberry bushes. Pollinator community structure varied by plant and year. Honeybees were the most numerous pollinators on all plants except blueberry bushes (39-95% of visits). Bumblebee numbers were high on blackcurrant (up to 28%) and blueberry bushes (up to 61%). Solitary bees visited all plants except blueberries. Honeybees, solitary bees, and hoverflies were most active in the middle of the day, while bumblebees became active earlier in the morning and remained active later in the evening. Pollinators also differed greatly in their temperature preferences. This knowledge gained is necessary for less harmful pesticide application management and the development of more sustainable agriculture to maintain pollinator diversity and thus reliable pollination in extreme weather conditions.

Soil degradation caused by water erosion in sloping hop gardens is definitely a serious issue because the space in inter-rows is without plant residues for most of the year in traditional cultivation. Cover crops in inter-rows of hop gardens and their efficiency in soil conservation are assessed in this article. There is only little research available in this area, and our data bring unique information on water erosion in hop gardens. Technologies with different types of cover crops were always compared with the conventional cultivation. The research was conducted within the years 2016-2020. A field rainfall simulator was used to determine the soil conservation effectiveness of selected technologies. The simulated rainfall was performed in two stages of cover crops growth with the main aim to measure the overall soil loss. The outcomes from the measurements confirmed that cover crops in inter-rows of hop gardens protect the soil surface from falling raindrops and significantly (P-value < 0.05) reduce soil loss. It can be concluded that this technology had a soil conservation effect already one month after sowing, and it is a basis for sustainable agricultural management on sloping hop gardens.

The influence of toxic elements, such as arsenic (As), cadmium (Cd), lead (Pb), and zinc (Zn), in the root zone of As-hyperaccumulator Pteris cretica 'Albo-lineata' and non-As-hyperaccumulator P. straminea, on the enzymatic activity of β-glucosidase, dissolved organic carbon (C) in soil, toxic element accumulation in fern roots, and root biomass were evaluated in a pot experiment. Ferns were cultivated in soils from the locality of Suchdol (control) and Litavka (high contamination) for six months. For all toxic elements, an increasing trend in their contents in the roots was observed with soil contamination for both ferns. Differences between ferns were observed in As and Zn accumulation. Pteris cretica had a significantly higher As accumulation than P. straminea. Zinc accumulation in the roots showed an opposite trend. A significant difference between ferns was confirmed in the dissolved organic C content. Our results showed a significantly higher content of dissolved organic C in the P. straminea root zone than in P. cretica. The significant effect of toxic elements in the soil on β-glucosidase activity was observed. Toxic elements inhibited β-glucosidase activity in the root zone of P. cretica, and an increase in P. straminea was determined in the Litavka soil. The results suggest a higher sensitivity of P. straminea to toxic element contamination in soil, leading to increased β-glucosidase activity and increased dissolved organic C content.

The effects of potato drip irrigation on soil nitrogen dynamics and potato yield was studied in small-plot field trials. The trials were evaluated at during three experimental times seasons (2016-2018). Four variants of irrigation were determined, ie non-irrigated, 60, 65 and 70 ASWC (Available Soil Water Capacity). At the same time, two pre-planting fertilization dates were set at a maximum of 120 kg N/ha a in divided i.e. 60 kg N/ha before planting and 60 kg N/ha by fertigation during vegetation. Pre-planting crop fertilization or in-season fertigation did not have any significant effect on the potato yields of most variants. In all studied parameters, the positive beneficial effect of irrigation was recorded and compared to the non-irrigated control. The mitigation of drought stress in plants during the growing season is the most important advantage of irrigation. In the trials, on average across all years and varieties, the yield of the irrigated variant increased by 41 % compared to the non-irrigated variant. Maintaining optimal soil moisture has a favourable effect use of applied fertilizers. The highest mineral nitrogen content in the soil was recorded for the variant without irrigation. Considering the increased use of nitrogen fertilizers, the subsurface drip line appeared to be optimal for the creation of suitable conditions for nitrogen availability to plants in the root zone.

To investigate the effect of microbial inoculum on soil heavy metal immobilisation, pot experiments were conducted with paddy soils contaminated by cadmium (Cd), lead (Pb), arsenic (As), and mercury (Hg), respectively. The results showed that the inoculation of Rhodopseudomonas palustris was more effective in the immobilisation of Pb and Cd in soils than the composite of R. palustris and Bacillus subtilis. Interestingly, a lower dosage of inoculum immobilised significantly more heavy metals than the higher dosage, potentially due to the competition of bacteria with limited nutrients. The heavy metal contents in rice grains also supported this finding, as less Pb and Cd were accumulated under the lower dosage. However, there were limited effects of microbial inoculations on the immobilisation of Hg and As. In general, our study indicated the effectiveness of R. palustris in immobilising Pb and Cd in soils and highlighted the importance of determining the optimal dosage of inoculum in bioremediation.

The impact of drip irrigation on structural stability of soil aggregates was studied in soils of an apple (Malus domestica Borkh.) orchard, developed on marl. The field study was carried out in a sloping (20%) terrain in the north-eastern Slovenia at three slope positions (upslope, mid-slope and downslope), involving a comparison of irrigated versus non-irrigated situations after 6 years of drip irrigation practice. Structural stability was studied in three soil layers (0-5, 5-15 and 15-30 cm) at the end of the irrigation season (in September). In the same samples, soil organic carbon, total carbonates and soil moisture contents were determined. Drip irrigation significantly reduced structural stability and soil organic carbon in the surface soil layer (0-5 cm), while total carbonates increased. Based on the whole set of data, structural stability was strongly positively correlated with total carbonates and negatively correlated with soil organic carbon. This means that the effect of higher level of organic matter mineralisation on structural stability, due to irrigation, is counterbalanced by the increase of total carbonates content in the fine textured calcareous soils. Thus, a negative effect of irrigation on soil organic carbon had less destructive consequences on structural stability than expected.

The study aimed to estimate and characterise soil organic matter under different land uses (cropland, grassland, and forest) and soil depths. The soil organic matter composition of the soil was assessed by diffuse reflectance infrared spectroscopy (DRIFT). Humic and fulvic acids (HAs, FAs) were extracted from soils and their compositions were evaluated by DRIFT. Low molecular mass organic acids content was also measured. Our result revealed that the largest differences of the spectra in the composition of organic matter were observed in the upper parts of the soil profile. The forest soil spectra had more intense aliphatic bands, carboxylic, and CH bands than spectra of grassland and cropland soils. The difference of HAs spectra was at 3 010 to 2 800/cm where the most intensive aliphatic bands were in forest soil HAs, followed by grassland and cropland soil HAs. The grassland topsoil FAs spectrum differs most from the other land uses. It has lower peaks around 1 660-1 600/cm and 1 200/cm than cropland and forest. The concentration of low molecular mass organic acid (LMMOA) was the highest in the forest soil and the most abundant acid was citrate.