This paper presents the main characteristics of Eutric Cambisols, their productivity potential expressed as land-rating, and their spatial distribution in Slovenia. Differences in soil properties ...were evaluated among the six predominant groups of Eutric Cambisols; classification was based on the parent material. In addition to individual characteristics affecting soil quality (texture, soil depth, amount of plant available water, pH, base saturation, cation exchange capacity), a comparison of land-rating values between the groups was also performed. We analysed 200 profiles excavated as part of the Slovenian Soil Mapping or other soil surveys conducted by the Center for Soil and Environmental Sciences, Biotechnical Faculty, University of Ljubljana. Our results show that Eutric Cambisols cover 15.5% of the area of Slovenia. Most Eutric Cambisols are on flysch (19.3%, 600 km²), followed by Eutric Cambisols on marl (12.7%, 398 km²). Eutric Cambisols on sandy gravel alluvial sediments, an important soil for crop production, cover 295 km² (9.4%). They have a favourable loamy texture and optimal pH. The flat terrain also contributes to this soil’s highest average weighted land-rating value (70 points). The average weighted land-rating value of all Eutric Cambisols is higher than the average weighted land-rating value of all agricultural and forest land in Slovenia, which is 36 points; this must be considered in spatial planning, as this type of land has a small share and above all, it must be protected from various degradations.
In low-input farming systems, where plant nutrition strongly depends on either organic matter inputs or nitrogen fixation by legumes, it is crucial to understand the effects of different crop residue ...management strategies on microbially mediated processes that influence nutrient dynamics. To evaluate different straw management options, we conducted a pot experiment with the following treatments: (1) control with no straw added (CON), (2) applying straw to the soil surface (SRF), simulating no-till, and (3) straw incorporating straw to the top 10 cm (INC), simulating minimum tillage. Another factor was slurry fertilization (with 3.2 t d.m. ha−1 or without). Throughout the experiment, CO2 efflux (µmol/m2/s) was measured regularly over a period of four months. Soil sampling was performed to monitor the abundance of the total bacterial, crenarchaeal and fungal communities, as well as nitrogen cycle microbial guilds and the dynamics of labile N and C fractions in the soils at different depths. Among straw treatments, significantly higher soil respiration was observed in INC and SRF compared to CON. Slurry fertilization increased soil respiration in all straw treatments. In the top 10 cm soil layer, the fungal abundance increased in INC compared to SRF and CON, whereas bacteria and crenarchaea did not respond. This effect was even more pronounced with slurry addition. The slurry also stimulated the abundance of certain N-cycle guilds, with the greatest increase in bacterial amoA-bearing nitrifiers and nirS, nosZI and nozII-bearing denitrifiers, particularly in the uppermost 0–1 cm soil layer. Straw treatment effects on N-cycle microbial guilds were less pronounced, while the coupled effect of straw incorporation and slurry was beneficial mostly for nosZ, again mainly in the top 1 cm soil layer. Compared to straw management, slurry fertilization had more potent effects on the abundance and performance of the investigated microbial communities.
Agro-ecosystems experience huge losses of land every year due to soil erosion induced by poor agricultural practices such as intensive tillage. Erosion can be minimized by the presence of stable soil ...aggregates, the formation of which can be promoted by bacteria. Some of these microorganisms have the ability to produce exopolysaccharides and lipopolysaccharides that "glue" soil particles together. However, little is known about the influence of tillage intensity on the bacterial potential to produce these polysaccharides, even though more stable soil aggregates are usually observed under less intense tillage. As the effects of tillage intensity on soil aggregate stability may vary between sites, we hypothesized that the response of polysaccharide-producing bacteria to tillage intensity is also determined by site-specific conditions. To investigate this, we performed a high-throughput shotgun sequencing of DNA extracted from conventionally and reduced tilled soils from three tillage system field trials characterized by different soil parameters. While we confirmed that the impact of tillage intensity on soil aggregates is site-specific, we could connect improved aggregate stability with increased absolute abundance of genes involved in the production of exopolysaccharides and lipopolysaccharides. The potential to produce polysaccharides was generally promoted under reduced tillage due to the increased microbial biomass. We also found that the response of most potential producers of polysaccharides to tillage was site-specific, e.g.,
had higher potential to produce polysaccharides under reduced tillage at one site, and showed the opposite response at another site. However, the response of some potential producers of polysaccharides to tillage did not depend on site characteristics, but rather on their taxonomic affiliation, i.e., all members of
that responded to tillage intensity had higher potential for exopolysaccharide and lipopolysaccharide production specifically under reduced tillage. This could be especially crucial for aggregate stability, as polysaccharides produced by different taxa have different "gluing" efficiency. Overall, our data indicate that tillage intensity could affect aggregate stability by both influencing the absolute abundance of genes involved in the production of exopolysaccharides and lipopolysaccharides, as well as by inducing shifts in the community of potential polysaccharide producers. The effects of tillage intensity depend mostly on site-specific conditions.
The aim of the study was to examine whether the effect of projected temperature rises due to the global climate change could accelerate plant litter decomposition in soils of overgrown grasslands. ...The experiment was carried out under natural conditions at the locations of Bohinj-Polje and Uskovnica with similar environmental conditions (precipitation, parent material and soil development, plant communities) and the difference in air temperatures. The average difference in monthly air temperatures during our study were higher in Bohinj for 4.4 °C (± 1.5 °C) than in Uskovnica. Nylon mesh bags with mixed plant litter from both locations were placed into the Of horizon of the soil profiles at both locations in autumn 2007. The litter bags were sampled successively at 4 sampling times until May 2009 in 5 replicates. The litter degradation, expressed as mass loss, was throughout our study 57.1 ± 1.2 % (0 - 526 days) in Bohinj, 57.3 ± 2.6 % (0 - 555 days) at Uskovnica. No statistically significant differences in litter decomposition rate and seasonal pattern of mass loss was found between the sites. The dynamics of the total content of cellulose and lignin, Corg and N and their soluble forms (DOC and DON) were similar between the sites as well. The lignin content in the plant material did not statistically significantly change during the experiment. The results of our experiment did not confirm the effect of the difference in average air temperature on decomposition rate decreases. The results did not confirm any effect from the difference in the average monthly air temperature between the sites on the plant litter decomposition in our study.
In recent decades, the use of heavy machinery in forest management has increased, causing compaction and alternations in soil morphology. As soil vulnerability to compaction is highly dependent on ...the type of soil and the current soil water content, rapid assessment of the suitability of the conditions for the use of machinery is of great importance for practice. The article discusses methods for rapidly determining the mechanical properties of soil. We tested the soil clump method, which was supplemented by the assessment of the appearance of the hand and handprint during preparation of the soil clumps, soil water content measurements and determination of the lower and upper limits of soil plasticity. The following soil types, which are common in Slovenian forest stands, were selected: brown soil on limestone and dolomite (Eutric Cambisol), dystric brown soil (Dystric Cambisol) and hypogley (Eutric Gleysol). The results of the study showed that, when dropped, the surface area of the clump increases with the water content of the soil, while at the same time the appearance of the clump, the soil residue on the hands and the appearance of the handprint change. Evaluation of the appearance of the hands and handprint represent supplements to the existing clump method, but can also be an alternative to it, as they can be both used independently. By determining the lower and upper limits of plasticity or soil strength, we indirectly assessed the risk of soil damage in forest production. Through the use of soil condition indicators, such as the appearance of the soil clump, the soil residue on the hands and the appearance of the handprint, we can quickly and easily assess the current working conditions in practise and thus prevent excessive soil deformation in forest operations.
Gaseous conditions at natural CO₂ springs (mofettes) affect many processes in these unique ecosystems. While the response of plants to extreme and fluctuating CO₂ concentrations (CO₂) is relatively ...well documented, little is known on microbial life in mofette soil. Therefore, it was the aim of this study to investigate the abundance and diversity of CO₂-fixing bacteria in grassland soils in different distances to a natural carbon dioxide spring. Samples of the same soil type were collected from the Stavešinci mofette, a natural CO₂ spring which is known for very pure CO₂ emissions, at different distances from the CO₂ releasing vents, at locations that clearly differed in soil CO₂ efflux (from 12.5 to over 200 μmol CO₂ m⁻² s⁻¹ yearly average). Bulk and rhizospheric soil samples were included into analyses. The microbial response was followed by a molecular analysis of cbbL genes, encoding for the large subunit of RubisCO, a carboxylase which is of crucial importance for C assimilation in chemolitoautotrophic microbes. In all samples analyzed, the “red-like” type of cbbL genes could be detected. In contrast, the “green-like” type of cbbL could not be measured by the applied technique. Surprisingly, a reduction of “red-like” cbbL genes copies was observed in bulk soil and rhizosphere samples from the sites with the highest CO₂ concentrations. Furthermore, the diversity pattern of “red-like” cbbL genes changed depending on the CO₂ regime. This indicates that only a part of the autotrophic CO₂-fixing microbes could adapt to the very high CO₂ concentrations and adverse life conditions that are governed by mofette gaseous regime.
In this study, we investigated the importance of plant cover for secondary succession and soil fungal community development in remediated substrates after EDTA washing of metal-contaminated soils. ...The abundance of the total fungal community, determined by ITS fungal marker genes (Internal Transcribed Spacer region), and root colonisation by arbuscular mycorrhizal (AM) fungi were monitored in two types of soil material (
calcareous and acidic
) sown with perennial ryegrass (
Lolium perenne
L.) and without plant cover (
bulk soil
). Four months after the start of the experiment, the abundance of ITS genes in the soil clearly showed that the presence of plants was the main factor affecting the total fungal community, which increased in the rhizosphere soil in most treatments, while it remained at a low level in the bulk soil (without plants). Interestingly, the addition of environmental inoculum, i.e., rhizosphere soil from a semi-natural meadow, did not have a positive effect on the abundance of the total fungal community. While fungal ITS genes were detected in soils at the end of the first growing season, arbuscular mycorrhizal (AM) structures were scarce in
Lolium
roots in all treatments throughout the first season. However, in the second season, more than a year after the start of the experiment, AM fungal colonisation was detected in
Lolium roots
in virtually all treatments, with the frequency of colonised root length ranging from 30% to >75% in some treatments, the latter also in remediated soil. This study demonstrates the importance of plants and rhizosphere in the development and secondary succession of fungal communities in soil, which has important implications for the revitalisation of remediated soils and regenerative agriculture.
Nitrous oxide (N2O) emissions from different agricultural systems have been studied extensively to understand the mechanisms underlying their formation. While a number of long-term field experiments ...have focused on individual agricultural practices in relation to N2O emissions, studies on the combined effects of multiple practices are lacking. This study evaluated the effect of different tillage no-till (NT) vs. conventional plough tillage (CT) in combination with fertilisation mineral (MIN), compost (ORG), and unfertilised control (CON) on seasonal N2O emissions and the underlying N-cycling microbial community in one maize growing season. Rainfall events after fertilisation, which resulted in increased soil water content, were the main triggers of the observed N2O emission peaks. The highest cumulative emissions were measured in MIN fertilisation, followed by ORG and CON fertilisation. In the period after the first fertilisation CT resulted in higher cumulative emissions than NT, while no significant effect of tillage was observed cumulatively across the entire season. A higher genetic potential for N2O emissions was observed under NT than CT, as indicated by an increased (nirK + nirS)/(nosZI + nosZII) ratio. The mentioned ratio under NT decreased in the order CON > MIN > ORG, indicating a higher N2O consumption potential in the NT-ORG treatment, which was confirmed in terms of cumulative emissions. The AOB/16S ratio was strongly affected by fertilisation and was higher in the MIN than in the ORG and CON treatments, regardless of the tillage system. Multiple regression has revealed that this ratio is one of the most important variables explaining cumulative N2O emissions, possibly reflecting the role of bacterial ammonia oxidisers in minerally fertilised soil. Although the AOB/16S ratio aligned well with the measured N2O emissions in our experimental field, the higher genetic potential for denitrification expressed by the (nirK + nirS)/(nosZI + nosZII) ratio in NT than CT was not realized in the form of increased emissions. Our results suggest that organic fertilisation in combination with NT shows a promising combination for mitigating N2O emissions; however, addressing the yield gap is necessary before incorporating it in recommendations for farmers.
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•Rain events were the main triggers for N2O emissions over maize growing season.•Cumulative emissions were highest in mineral, followed by organic and no fertilisation.•Mineral fertilisation increased share of bacterial ammonia oxidizers within the bacterial community.•N2O genetic consumption potential was higher in no-till organic-fertilised than mineral or unfertilized plots.
The use of pesticides and their potentially negative effects on the environment are currently widely debated. However, it is difficult to imagine sufficient food production completely without their ...use; therefore, more attention has to be given to managing their use by considering site-specific spatial environmental data. In this study, the use of the FOOT-CRS (Footprint-Catchment Scale) tool, which was developed in the European project: “Functional tools for pesticide risk assessment and management”, is presented on a model location in the Apače Valley, Slovenia. The results clearly showed that the potential negative impacts of selected pesticides can be foreseen in advance; therefore, the pesticide usage can be adjusted accordingly to environmental and spatial characteristics of a given catchment. Pesticide leaching risk assessment on the catchment scale strongly depends on input spatial data quality. A soil map in the scale of 1:25,000 does not sufficiently cover the variability of soil properties; therefore, pedological data should be supplemented on a larger scale, with the final aim of knowing basic soil properties on the field level.
Uporaba fitofarmacevtskih sredstev (FFS) in njihovi potencialno negativni učinki na okolje so dandanes zelo odmevni. Vseeno pa si ne moremo predstavljati zadostne pridelave kmetijskih rastlin povsem ...brez njih, zato je treba več pozornosti nameniti obvladovanju njihove rabe z upoštevanjem prostorskih okoljskih podatkov. V prispevku smo prikazali uporabo orodja FOOT-CRS (Footprint-Catchment Scale), ki je bilo razvito v evropskem projektu z naslovom Functional tools for pesticide risk assessment and management na modelni lokaciji na Apaškempolju. Rezultati nazorno kažejo, da lahko potencialne negativne vplive izbranih FFS predvidimo vnaprej, na podlagi česar lahko izbor in uporabo FFS pravočasno ustrezno prilagodimo okoljskim in prostorskim specifikam posameznega vodozbirnega območja, porečja oziroma povodja. Ocene tveganja izpiranja FFS so močno odvisne od kakovostnih prostorskih vhodnih podatkov. Pedološka karta v merilu 1 : 25.000 ne zajame variabilnosti talnih lastnosti dovolj natančno, zato je nujno dopolnjevanje pedoloških podatkov v večjem merilu, s končnim ciljem poznavanja talnih lastnosti na ravni parcele.KLJUČNE BESEDEonesnažila, izpiranje, tla, podnebje, vodni viri, karte ranljivosti, Apaško polje
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