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Context. Although both plant cover and mulch are considered for erosion control in arid and semi-arid regions, they have divergent impacts on soil ecology. Aim. We examined the effects of orchard floor management practices on the density and diversity of soil free-living nematode communities and relevant soil abiotic properties. Methods. Soils were sampled in winter in a citrus orchard in the Sharon region of Israel from plots that for 6 years had been under (1) annual native species; or (2) Avena sativa and Vicia villosa, planted between tree rows; or (3) woodchip mulching along tree rows. There were two control sites: (4) bare soil between tree rows and (5) bare soil along the tree rows (both common practice). Key results. Nematode communities and their trophic diversity were significantly impacted by floor management. Significant increases in soil moisture under plant cover, and higher organic matter and water-holding capacity for all covered orchard floors could be related to nematode changes. Shifts in nematode feeding group structure suggest a shift in the type and availability of soil carbon pools. Conclusions. There was a strong association between orchard floor management and soil free-living nematode communities, indicating a shift in the soil food-web structure and functionality. Bare soil harboured fewer nematodes, but more complex communities dominated by persisters, while seeded plant cover had a greater nematode abundance dominated by coloniser communities, indicating increased availability of resources. Implications. Results reveal the importance of integrating biological information in performance index determinations for improving soil management decisions, suggesting these relationships as sensitive bio-indicators of soil health. Keywords: cover crops, functional diversity, mediterranean, mulching, nematodes, orchard, soil degradation, soil ecology., Introduction Any agricultural practice affects the functioning of soil biota (Dunn et al. 2021). This needs to be taken into consideration when contemplating a shift from conventional, intensive agriculture, characterised [...]

Conventional, sustainable or organic farming practices are assumed to have distinct effects on soil fertility and health. This is often supported by arguments linking management and resulting soil parameters to crop yield and produce quality. Soil microbial communities are sensitive to management practices that alter soil water fluxes and the pools and fluxes of nutrients. These effects might be accentuated in arid or semiarid agriculture. Conversion to vineyard use, under Mediterranean conditions, and the subsequent application of different management types creates the conditions for divergent soil microbial communities. An off-season survey of variably managed vineyards located in a Mediterranean climate showed that both organic and conventional vineyard management had the most distinct impact on soil abiotic parameters, and on the bacterial and fungal communities; both organic and sustainable management enhanced soil organic carbon, water holding capacity and nitrogen availability. The sustainable management led to soil microbial communities most similar to the natural conditions. Fungal diversity was better than bacterial diversity at discriminating between soils under different management types. Classes of the dominant Ascomycota phylum had best discriminating power; Mucoromycota declined significantly after conversion to vineyard use and was a key taxonomic indicator for such conversion. Regarding bacterial communities, a focus on functional categories, e.g. nitrogen-fixing taxa, may be more informative than total diversity assessments. Keywords: arbuscular mycorrhizae, land-use conversion, Mediterranean, microbial diversity, nitrogen-fixing bacteria, organic, soil fertility, vineyard., Introduction Demands from consumers and policy makers for more sustainable agriculture led to the emergence of numerous sustainable vineyard programs, which are then reflected in wine labels (Viers et al. [...]

Results of a recent multiyear experiment conducted on an agricultural plot that was recently converted from boreal forest (Labrador, Canada) suggested that NPK fertilizers contributed to better crop establishment and higher yield but only when it was applied along with biochar. The failure of fertilizer only treatments to allow crop establishment and desirable growth and yield could be related to the deficiency of one or more micronutrients. Consequently, a missing element trial with a number of micronutrients (Mn, Cu, Zn, and Mo) was initiated on the same soil to investigate whether biochar can facilitate the availability of one or more of these micronutrients, contributing to crop growth and yields. Results show that the incorporation of chemical fertilizers with biochar produced significantly higher yields than in the absence of biochar. Furthermore, in the absence of biochar, the addition of micronutrients (i.e., Mn, Cu, Zn, and Mo) did not significantly increase yield. On the other hand, among the treatments that included biochar, the absence of a micronutrient (i.e., only three of the four micronutrients included) had either no effect (e.g., absence of Mn or Zn) or was associated with the increased yields (i.e., absence of Cu or Mo). Thus, it is proposed that while all tested micronutrients were present in the podzolic soil, with Cu and Mo possibly oversupplied, co-application with biochar enhanced both macronutrient and micronutrient utilization by plants. The data on the availability of micronutrients in the soil, their concentration in plants, and total uptake also support this conclusion. Thus, biochar facilitates the plant uptake of both naturally occurring and added micronutrients, and associated crop productivity, in a podzolic soil typical for lands converted from forest to agricultural use in the boreal ecoregion of Labrador. These results also challenge the view that micronutrients must always be added to Podzols to achieve maximum productivity; biochar-mediated micronutrient plant uptake deserves consideration when managing Podzols.

Boreal lands have long been considered unsuitable for agriculture. Climate change projections support a shift towards increased agricultural production in boreal ecosystems via land use conversion. Depending on the conversion protocol, the new plough layer may variably reflect the properties of different soil depths. This study assessed how adding mineral or organic fertilizer sources to distinct soil layers within ploughing depth (0–15 cm [topsoil] or 15–30 cm [subsoil]) affects nutrient uptake and crop productivity. Locally relevant organic waste fertilizers (dairy manure [DMN], recirculating aquaculture system supernatant [SUP] and slurry [RAS]), were compared against mineral fertilizer. Tall fescue was used to verify agronomic responses. Starting available nutrient concentrations were balanced as necessary with mineral N and P fertilizers. Except for NH4‐nitrogen, both soils were of apparent similar fertility (total C < 1%); unfertilized, neither could support significant plant growth. Subsoil‐based growth was fast but limited in time reflecting immediately available nutrients. Topsoil led to delayed, extended growth. This might be due to dichotomous priming effects: during the duration of the experiment up to 36% of subsoil carbon was lost, while the topsoil gained up to 49% carbon, most apparent for DMN. While RAS led to the greatest N and P acquisition efficiencies for topsoil, it had no such effect for subsoil, suggesting distinct fixation and mineralization processes. Dissimilar C cycling and nutrient acquisition for the two soil depths indicates that site‐specific considerations that include soil health parameters with commonly tested available nutrients are needed where podzols are farmed after land‐use conversion. [ABSTRACT FROM AUTHOR]

Recovery of soil health offers insights into the mechanisms underpinning the stability of remediated ecosystems. Indirect assessment of enzymatic activity potential using substrate induced respiration (SIR), is commonly used to evaluate changes in soil microbial activity profiles, with their links to environmental and management factors. In this study, community level physiological profiling (CLPP) was employed to assess the impact of time on surface coal mine soil remediation. When compared with an adjoining control site, analysis of CLPP parameters offer useful insights and prospective tools for assessing soil health, following mining and remediation activities. [ABSTRACT FROM AUTHOR]

Repetitive long-term fertilizer application leads to phosphorus (P) accumulation in agricultural soils. This can pose environmental risks if the soil's phosphorus storage capacity is not well understood and considered when planning nutrient management. We investigated the P sorption capacity (PSC) in the surface (0-20 cm, n = 23) and subsurface (20-40 cm, n = 23) of long-term managed podzolic soils in Newfoundland (Nfld), Canada, through batch adsorption using two P concentrations of 150 and 500 mg P L-1, and developed pedotransfer functions to estimate PSC using selected soil properties. Also, the correlation between actual PSC, soil properties, and estimated Phosphorus saturation index (PSI) and soil P sorption capacity (SPSC) both from standard soil test were evaluated. The surface and subsurface soils provided similar median PSC (1.34 and 1.32 mg g-1, respectively, p = 0.16) when examined with the 150 mg P L-1 solution. With 500 mg P L-1 solution, the subsurface soils had significantly higher median PSC than the surface soils of the same fields (2.74 and 2.27 mg g-1, respectively, p = 0.02); and had a better linear relationship (R2 >0.40, p <0.05) with SPSC than at the lower P concentration. The surface soils had significantly higher extractable median P in water, citric acid, and Mehlich-3, higher soil organic matter (SOM), moisture content, Mehlich-3-Fe, -Ca, and -K, PSI, electrical conductivity, silt, and clay contents, while Mehlich-3-Al, Mehlich-3-Al: Fe ratio, SPSC, and sand were lower than those in the subsurface soils. All soils had comparable pH (~6.3). Pedotransfer function revealed that the PSC could be predicted using SOM, Mehlich-3-Al, and Mehlich-3-PICP and thus may be employed for developing testable hypotheses relevant to environmentally and economically viable P management strategies for acidic soils in boreal regions. [ABSTRACT FROM AUTHOR]

Abstract: Land application of organic wastes can lead to contamination of ground- and surface waters. The pathway taken by particulate contaminants, such as microorganisms, is entirely dependent on the partitioning [...]

We evaluated the impact of the manure type used in soil--manure mixtures on the detection of culturable E. coli as tested in water quality monitoring. A series of incubation experiments, lasting up to 200 d, allowed evaluation of the potential impact of manure x soil interactions on the augmentation of culturable E. coil Two soil types (sandy loam and a silt loam), two manure types (liquid swine manure and solid beef cattle manure), and three temperature levels (4, 12, and 20[degrees]C) were investigated. The significance of the presence of competing microorganisms was estimated by comparing results from manure mixtures with sterile and nonsterile soils. Water content in the soil-manure mixtures was maintained close to field capacity to eliminate the specific impact of water availability. We found that culturability of the indicator organism, E. coil changed with time and was dependent on the type of manure used and its interaction with soil. Escherichia coli could be cultured fur a longer time from soils with liquid manure additions. Whereas E. coli numbers were initially higher from soils treated with solid beef cattle manure, their numbers decreased more rapidly and the duration of their apparent survival was shorter. Resilience of culturable E. coli was independent of their initial numbers in manure.

A hypothetical study was conducted to prove that addition of biosolid nutrients to soil would enhance recovery of Escherichia coli naturally found in soil. The experimental effect was most marked for the deeper soil layers, with increases of about 2.6 orders of magnitude in E. coli most probable number.

Despite the agricultural expansion into Canada's boreal ecoregion, little is known about the phosphorus (P) adsorption capacity in natural and managed Podzols' soil profiles. This information is critical for informing management decisions for P use efficiency and mitigating related environmental risks. Thus, this study aimed to evaluate P adsorption characteristics of podzolic horizons in natural and managed soil using nonlinear Langmuir and Freundlich adsorption models. A batch adsorption experiment was conducted using soils collected from distinct horizons of forested and managed fields in eastern and central Newfoundland, Canada. Nonlinear Langmuir and Freundlich fitted models had r values >.99 regardless of horizons, locations, and management history. The organic LFH, a surface horizon typical for forested Podzols, and a long‐term managed Ap horizon had the highest P retention capacities when compared to either newly converted soils or soils used as tree nursery following conversion from natural forest. A significant linear correlation and multiple regression models (p <.05) were established between P adsorption parameters and selected soil properties. Results suggest that following conversion from forest to agricultural use, long‐term management that includes tillage and lime and fertilizer application creates an Ap horizon with strong adsorption capacity, which could still fix P and serve as a source of P. The newly converted soils and the deeper soil horizons, for both natural and converted lands, do act mainly as P sinks; hence, crops may need larger quantities of P fertilizer increasing fertilizer expenses and also increasing future legacy P. [ABSTRACT FROM AUTHOR]

Apparent magnetic susceptibility (MSa) as recorded by electromagnetic induction (EMI) instruments could offer relevant information about non-soil subsurface features. It is less affected by natural soil properties than its prominent counterpart, i.e., apparent electrical conductivity (ECa). Hence, MSa is generally a promising approach to investigate artificial inclusions and structures in soil. However, while the origin depth of EMI based ECa is widely accepted, the depth sensitivity (DS) of MSa measurements remains poorly understood. The depth interpretation of MSa is particularly challenging due to negative values especially for objects that are randomly distributed over different depths. Here we assessed the performance of both multi-coil (MC) and multi-frequency (MF) EMI sensors for identifying and determining the DS of MSa measurements in shallow soils through detection of buried small targets of known conductivity. Two experiments were conducted in a sandy loam podzolic soil in western Newfoundland, Canada. Materials of different conductivities, including metal and plastic targets, were buried at depths between 20 and 80 cm. Three inter-coil separations (32, 71 and 118 cm) of the MC sensor and four factory-calibrated frequencies (18, 38, 49 and 80 kHz) of the MF sensor were tested in both horizontal and vertical coil orientations. The MC sensor clearly detected all four metal targets from three coil separations in both coil orientations while the MF sensor identified more anomalies than targets limiting its information value. Based on the measurements from MC and the theoretical DS function, a criterion was developed and validated to assess the potential depth origin of MSa. We found that negative or less than the background values occur, if the depth of the target is shallower than 0.36 times the coil distance of the employed EMI sensor. According to this criterion, the depth origins of metallic targets were correctly identified under the assumption of low induction numbers, even if values were negative. [ABSTRACT FROM AUTHOR]

The spatial variability in soil physical and hydraulic properties for a managed podzol was assessed using soil apparent electrical conductivity (ECa). Two EMI sensors, the multi-coil (MC) and multi-frequency (MF), were adopted for measurement of ECa on a silage- corn experimental plot in western Newfoundland, Canada. Results demonstrated a significant relationship between the ECa mean relative differences (MRD) and the soil moisture content MRD (R2 = 0.33 to 0.70) for both MC and MF sensors. The difference in depth sensitivity between MC and MF sensors accounted for the variation (0.015 to 0.09) in ECa standard deviation of the relative differences. A significant linear relationship was found between the ECa MRD and sand (R2 = 0.35 and 0.53) or silt (R2 = 0.43), but not with clay (R2 = 0.06 and 0.16). The spatial variability of the ECa-based predictions (CV = 3.26 to 27.61) of soil properties was lower than the measured values (CV = 5.56 to 41.77). These results inferred that the temporal stability of ECa might be a suitable proxy to understand the spatial variability of soil physical and hydraulic properties in agricultural podzols. [ABSTRACT FROM AUTHOR]

Highlights • Human trampling on soil biota and abiota in Oulanka Natural Reserve was evaluated. • Soil compaction affected functional and taxonomic diversity of microbial communities. • Physicochemical features of soil were governed by the extreme abiotic environment. Abstract Functional and taxonomic diversities of microbial communities in Arctic soils are governed by the extreme abiotic environment and affected by human activities. We assessed the impact of trampling by humans on biotic and abiotic parameters relevant to soil health at the Kiutaköngäs Trail, Oulanka Nature Park, Finland. Soil was sampled from the 0 to 2 cm, 2 to 5 cm, and 5 to 10 cm layers for four levels of trampling pressure: heavily trampled, medium trampled, low trampled sites, and non-trampled control. Measured and estimated abiotic soil parameters included organic matter, pH, water-holding capacity, and bulk density for each soil sample. Biotic parameters included determination of microbial biomass, CO 2 evolution and MicroResp®-based community level physiological profiles, and as well as bacterial taxonomic diversity. Results have shown that total organic matter amount might not change significantly under trampling. Nevertheless, absolute substrate utilization, functional diversity, and respiration varied with depth, significantly declining in the immediate subsurface under the trampled sites. On the other hand, the most extreme stress associated with the greatest trampling intensity was associated with an increase in taxonomic diversity but with a proportional decline in Acidobacteria abundance, in line with the increase in pH. [ABSTRACT FROM AUTHOR]

Food webs and the functional status of soils are governed primarily by microbial carbon and nitrogen fluxes as determined by ecosystem type and management. In boreal regions, expanding and intensifying agriculture affects the functional status of soils due to biodiversity, carbon, and nitrogen losses. The status of northern soils must be monitored using informative, standardised methods that are comparable across land uses, managements, and scales. Food web nodes sensitive to complex changes in the soil environment, such as free-living nematodes, can be utilised to monitor alterations in the functional state of natural systems and inform management decisions to ensure that new and established agriculture is environmentally sustainable. The objectives of this a-priori review were to 1) describe the likely impacts of land use and land use change on nematode communities and indices in boreal regions, 2) determine if nematodes respond differently to land use and land use change in the global biomes, and 3) identify literature gaps related to nematodes in the boreal biome to draw attention to future research needs. Soil quality bioindicators were compared and 31 published, peer-reviewed, in-situ studies found in Web of Science and Scopus databases in March 2020 that assessed the impacts of land use and land use change on free-living nematode parameters across global biomes were systematically summarised. While the northern biomes have greater abundances of nematodes than other biomes, the literature search found zero articles pertaining to nematodes in boreal or Arctic agricultural systems highlighting the need for future work. Given the key roles that free-living nematodes have in the food web, their longer and more stable generation times than microbes, and relatively well-known taxonomy, life history traits, and feeding habits, the authors propose that nematodes could and ought to be employed as indicators of functional changes in boreal agricultural soils. [Display omitted] • New and existing boreal agriculture must be monitored for sustainability. • Bioindicators can support management decisions pertinent to soil functions. • Nematode assessments are reliable, cheap, and accessible. • Literature on free-living nematode from boreal and arctic ecosystems is limited. [ABSTRACT FROM AUTHOR]

Numerous studies conducted so far have shown that biochar has a significant effect on physical, chemical and biological properties of soils. Biochar can be used to alleviate the effects of soil contamination with organic and inorganic compounds, for instance, to reduce the mobility of heavy metals. The aim of the research was to evaluate the effect of pig manure and poultry litter, as well as biochars produced from these materials at a temperature of 300 °C on Cu, Cd, Pb and Zn contents in mobile and organic matter-bound forms in soil. The research was conducted under laboratory conditions. The materials were introduced into sandy acid soil in doses of 0.5, 1.0 and 2.0% w/w. The application of pig manure-derived biochar ( BPM) and poultry litter-derived biochar ( BPL), depending on the amount added, reduced the mobility of copper from 28 to 69%, from 77 to 100% in the case of cadmium, from 94 to 99% in the case of lead, and from 15 to 97% in the case of zinc. The 2% amendment of pig manure ( PM) and poultry litter ( PL) caused an increase in the content of Cu extracted with NH4 NO3 in comparison with the control treatment. A similar situation was observed in the case of zinc after the application of 0.5 and 1% amendments of pig manure ( PM). Cu, Cd, Pb and Zn contents extracted with 0.025 mol C10H22N4O8 were higher than contents of these elements extracted with 1 m NH4 NO3, mainly due to different extraction force of the extractants. The obtained results indicate that, compared with the content determined in soil from the control treatment, 1 and 2% amendments of both unconverted and thermally converted materials to the soil had a greater effect on contents of Cu, Pb and Zn in the organic matter-bound fraction than the 0.5% amendment. The organic materials applied did not affect the content of cadmium in organic matter-bound fraction. [ABSTRACT FROM AUTHOR]

In temperate climates with surplus precipitation and low temperatures during autumn and winter, nitrate catch crops have become crucial in reducing nitrate leaching losses. Preferably, the N retained by the catch crop should remain in the soil and become available to the next main crop. Fodder radish ( Raphanus sativus, L.) has emerged as a promising nitrate catch crop in cereal cropping, although the course of remineralization of residue N following termination of this frost-sensitive crucifer remains obscured. We incubated radish residues of different age (different planting and harvest dates) with a loamy sand soil; mineralization of residue N was determined after 1, 2, 4 and 7 months of incubation at 2 °C and 10 °C. Incubations with soil only and with residues of white mustard ( Sinapis alba, L) and perennial ryegrass ( Lolium perenne, L.) were included as references. Using linear regression, net N release was fitted to plant chemical characteristics (initial concentrations of N, fibre fractions, lignin and C/N ratio). Residue C/N ratio (ranging from 10 to 25) and N concentration (ranging from 17 to 40 mg N/g dry matter) showed superior fits to net N release at both temperatures ( r2, 0.64-0.94) while fibre analyses provided inferior fits ( r2, 0.12-0.64). This was true across planting date and plant age. Net N release after 7 months of incubation at 2 °C and 10 °C accounted for up to 40% and 50% of residue N, respectively. During most of the incubation period, nitrate dominated the mineral N pool at both temperatures. The N mineralization and nitrification potential at these low soil temperatures suggest that a considerable fraction of the N captured by nitrate catch crops may be remineralized, nitrified and thus available for plant uptake but also for loss by leaching and denitrification. [ABSTRACT FROM AUTHOR]