Soil Biological Quality Research Articles

Soil microbial activity improved while intensifying vegetable production by use of plant-based fertilisers, cover crops and reduced tillage

Frequent soil cultivation in intensive vegetable production is detrimental to soil quality. Combining several sustainable management techniques, such as increasing organic matter input and plant diversity, and reducing soil cultivation, could benefit biological soil quality. We designed a crop rotation with a system approach, combining plant-based fertilisers, cover crops and reduced tillage, while growing more crops (sustainable intensification, SI). We compared this approach to common practice (CP), where animal manure fertilisers, no cover crops and ploughing were employed in a standard organic crop rotation on sandy loam in Denmark. Treatments were initiated in 2017, and two sets of contrasts, each comparing across cropping systems and specific crop rotations, were investigated in the second and third year of implementation: lettuce-leek double-cropping (SI) vs. leek sole-cropping (CP), and onion-lettuce intercropping (SI) vs. lettuce-lettuce double-cropping (CP). Soil microbial activity was assessed by β-glucosidase and dehydrogenase activity and potential N mineralisation over 28-days incubation. Root growth was investigated using minirhizotrons. The risk of N leaching was estimated from soil mineral N content at 0–2.5 m depth in autumn. β-glucosidase and dehydrogenase activity increased by 27–107% under SI compared to CP in the third year after implementation. SI improved potential N mineralisation by 12–52 kg N ha−1 before and after spring fertilisation both years. Increased soil fertility under SI contributed to 1.3 to 2.3 times higher plant N uptake (except for lettuce/onion first year), and 1 to 2.7 times higher marketable yields, but only minimally affected root depth. Despite higher N fertilisation, risk of N leaching did not rise under SI. The beneficial effects of SI were attributed to the combination of higher N fertilisation (53–144 kg N ha−1 more) as organic matter addition (2–3 Mg carbon ha−1 more), growing cover crops, and reducing soil tillage. Combining these techniques is promising for improving soil microbial activity in a sustainable way for highly intensive organic vegetable production.

Sustainable soil management: Insights from a 47-year maize-wheat cropping system study

Continuous monitoring of soil quality is vital to understand the effects and to identify best management practices for sustainable agroecosystems. This study focuses on evaluating the soil quality and crop yield sustainability in a long-term maize-wheat cropping system experiment spanning 47 years. Physical, chemical, and biological soil quality indicators were assessed at two soil depths (0–0.15 m and 0.15–0.30 m) under eleven fertilizer and amendment regimes i.e., 50 % NPK, 100 % NPK, 150 % NPK, 100 % NPK + Zn, 100 % NPK+ hand weeding, 100 % NP, 100 % N, 100 % NPK + farmyard manure (FYM), 100 % NPK(S), 100 % NPK + lime and control, laid out in a completely randomized block design. Principal component analysis (PCA) was employed to select a minimum data set (MDS) of indicators for soil quality assessment, followed by weighted additive approach to calculate the soil quality index (SQI). Results showed that balanced dose of NPK fertilizers, in combination with FYM or lime, enhanced average wheat grain yield by 39.9 and 29.4 % over sole 100 % NPK fertilizers, respectively. Treatment 100 % NPK + FYM recorded a significant improvement in aggregate stability, available nutrients, microbial biomass over control and 100 % NPK. The highest value of SQI (0–0.15 m) was recorded in 100 % NPK + FYM (0.99), followed by 100 % NPK + lime (0.86) and lowest in 100 % N (0.41). Omission of NPK, PK, K and S from fertilizer regime caused a decline of respective 33, 39, 22 and 6 % in the SQI, whereas, all the treatments recorded a decline in SQI in sub-surface layer. The average contribution of MDS towards the SQI of 0–0.15 and 0.15–0.30 m depth was labile carbon (LC) (30 %) > microbial biomass N (MBN) (28 %) > mean weight diameter (MWD) (17 %) > pH (16 %) > available K (6 %) and LC (33 %) > N mineralization (24 %) > MWD (22 %) > pH (21 %), respectively. The SQI positively correlated with average grain yield and SYI, highlighting the importance of soil quality for sustainable crop production. This research underscores the significance of continuous soil quality monitoring and use of balanced fertilization, organic manure and lime in maintaining soil health and crop productivity in agroecosystems.

Biochar derived from rice husk: Impact on soil enzyme and microbial dynamics, lettuce growth, and toxicity

This study was set to investigate the effects of rice husk biochar (RHB) on soil characteristics and growth of lettuce (Lactuca sativa). A comprehensive research approach was employed to examine the effect of different RHB concentrations (i.e., 0–1.5%) on soil pH, soil enzyme activities (i.e., alkaline phosphatase, beta-glucosidase, and dehydrogenase), soil microbial community, lettuce growth, and earthworm toxicity. The results showed that, within the studied RHB concentration range, the RHB application did not have significant effects on the soil pH. However, the enzyme activities were increased with increasing RHB concentration after the 28 d-lettuce growth period. The RHB application also increased the abundances of the bacterial genera Massilia and Bacillus and fungal genus Trichocladium having the plant growth promoting abilities. Furthermore, the study revealed that the root weight and number of lettuce leaves were significantly increased in the presence of the RHB, and the growth was dependent on the RHB concentration. The improved lettuce growth can be explained by the changes in the enzyme and microbial dynamics, which have resulted from the increased nutrient availability with the RHB application. Additionally, the earthworm toxicity test indicated that the tested RHB concentrations can be safely applied to soil without any significant ecotoxicity. In conclusion, this study underscores the potential of RHB as a soil amendment with positive effects on crop growth, highlighting the utilization of agricultural byproducts to enhance soil biological quality and plant growth through biochar application.

Meta-analysis unveils differential effects of agroforestry on soil properties in different zonobiomes

AimsCurrent comprehensive meta-analysis study aims to explore how agroforestry practices influence soil quality across different climate zones. Since numerous studies proposed agroforestry as the promising agroecological farming systems over conventional monoculture systems to maintain soil quality and to regenerate disturbed soil to counteract the negative consequences of global extensive agricultural approaches.MethodsBy employing the comprehensive meta-analysis technique on data from 125 studies conducted in tropical, temperate, and Mediterranean environments, we quantitatively assessed the effects of agroforestry on physical, chemical, and biological soil quality indicators.ResultsRates of soil erosion, the most important indication of land degradation, were improved in agroforestry systems compared to monocultures, especially in temperate (-138%) and Mediterranean soils (-40%), due to agroforestry-induced improved soil texture, aggregate stability, and soil water regulation. Soil acidification was decreased in tropical (-128%) and Mediterranean soils (-96%), but increased in temperate soils (+ 104%) due to agroforestry practices. Low temperate soil pH suggests high Ca2+ leaching losses as evidenced by decreased Ca2+ (-68%) and increased Fe2+ (+ 129%) and Al3+ (+ 235%) contents. Agroforestry systems increased organic matter accumulation in temperate (+ 86%) and Mediterranean soils (+ 65%), carbon sequestration in all climatic zones (+ 48%: 33–73%), and respiration rates in temperate (+ 119%) and tropical soils (+ 105%). Soil microbial communities, enzyme activities as well as nutrient cycling and availability were generally enhanced in agroforestry systems compared to monocultures.ConclusionsOur results provide compelling evidence that agroforestry practices can contribute substantially to sustainable improvement of global soil quality.

Sources, Persistence, Ecotoxicology and Transformations of Anticancer Pharmaceutical Drug Residues in the Soil Environment: A Review

Release and environmental consequences of drug residues pose a major challenge for soil quality management. This review aims to synthesis the literature related to the transformations of anticancer drugs at the soil-water interphase and their ecological effects. Pharmaceutical drugs, including anticancer drugs originate form point and non-point sources of human and animal background. While detrimental effects of anticancer drug residues on human health are widely reported, a relatively little body of knowledge focuses on their persistence, decomposition and interaction with soil biological health and quality. Assessment of the potential ecotoxicological effect of the residues of anti-cancer drugs is far less frequent compared to other xenobiotics. However, a substantial concern is growing to understand the fate of these drug residues in the environment, particularly, under high environmental risk scenarios. Sewage sludge and hospital wastewaters are the primary sources of anticancer drug residues into the soil and their effects and transformations in soil depend on nature and persistence of drug residues. Depending upon their structure, anticancer drug residues can undergo biodegradation and biochemical transformations to form highly mobile molecules, which move into surface and ground waters, ultimately end up in the soil to alter microbial communities and their functions associated with flow of energy, nutrient cycling and ecosystem functions. This manuscript reviews the behavior of anticancer pharmaceutical residue in the soil environment in terms of effects on soil functions and quality by summarizing the limited available data.

Soil microbial biomass carbon and Jatropha curcas yield intecropping with forages and crop species

The domestication of Jatropha curcas L. in the Brazilian territory has been boosted by its great potential in the production of grains, oil and, in particular, its adaptation in different soil and climatic conditions. The aim of this research was evaluate the soil biological quality through the soil microbial biomass carbon and its indices derivate (metabolic and microbial quotient) under J. curcas intercropping with many forages species, legumes and annual crop rotation systems, as well as the accumulated production of J. curcas grains and oil. The experiment was conducted in a commercial area in the randomized blocks experimental design with the treatments arranged in a 12 x 2 factorial design, with four repetitions, resulting in 12 treatments with cropping systems and 2 sampling times (February 2012 and May 2012). Soil sampling was performed in February and May 2012, at 0 at 10 cm layer and four composite samples were collected in each cropping system, from five subsamples in each plot. J. curcas intercropping with B. ruziziensis, favors the maintenance of the community of soil microorganisms compared to the treatment with the species P. maximum cv. Massai and Cajanus cajan, which promoted decreasing in soil organic matter dynamics, when compared to the other cropping systems. The monocropping systems of J. curcas and intercropping in rotation systems 2 and 3 achieved higher yields of J. curcas grains and oil over three seasons.

Effect of Different Plant Growth-Promoting Rhizobacteria on Biological Soil Properties, Growth, Yield and Quality of Oregano (Origanum onites L.)

Intensive agriculture uses continuous chemical fertilizers to increase crop yields, but excessive use of fertilizers leads to environmental pollution, permanent changes in physicochemical conditions in soil ecology, deterioration of soil biological health, leaching of nutrients, surface and groundwater pollution and eutrophication. Plant growth-promoting rhizobacteria (PGPR) are becoming increasingly important for ensuring crop safety, increasing nutrient uptake and output, lowering fertilizer costs, preventing environmental contamination and promoting sustainable agriculture and agricultural resources. Therefore, the purpose of this study was to identify and evaluate the effects of fifteen bacteria strains that were isolated from various acidic rhizospheric soils as biofertilizers on soil biological properties. Growth, yield and quality traits were analyzed, and various PGPR were identified using 16S ribosomal RNA of Turkish oregano. Fifteen bacterial inoculations with 1-aminocyclopropane-1-carboxylate (ACC) deaminase, N2-fixing, P-solubilizing and/or IAA-producing genes were used in the experiment, which was carried out in a randomized block design with five replicates (each with three pots) and a control without inoculation. Increased biological activity in soil inoculated with bacteria with multiple traits was confirmed by high C and N content in microbial biomass, urease, dehydrogenase and acid and alkaline phosphatase activities. Essential oil content, oil yield, thymol and carvacrol contents increased by 0.5–40.1%, 5.9–71.9%, 0.07–16.7% and 0.3–9.2%, respectively, as a result of bacterial inoculation. Oil content ranged from 2.02% to 2.83%; carvacrol (66.1–72.2%) was the main constituent, followed by thymol (14.5–16.9%) and linalool (1.38–3.68%). Two large PGPR groups were formed based on genetic distance analysis. Responses were variable and depended on the inoculant strain and the parameters being evaluated. The results indicate PGPR has clear potential for improving the yield of cultivated aromatic and essential oil plants, such as oregano.

Impact of different co-composted poultry manures on the chemical and biological quality of the calcareous soil

Impact of different co-composted poultry manures on the chemical and biological quality of the calcareous soil

Estimating Soil Organic Matter (SOM) Using Proximal Remote Sensing: Performance Evaluation of Prediction Models Adjusted at Local Scale in the Brazilian Cerrado

The quantification of soil organic matter (SOM) has increased over the years, especially in the Brazilian Cerrado region, one of the most important areas for grain production in the country. In this area, SOM content tends to be low, which directly impacts the physical, chemical and biological quality of soils. Thus, the use of spectroradiometry has been widely evaluated to investigate whether it can be used as a faster, more reliable and cheaper solution to meet the SOM estimation. In this context, the objective of the present paper was to evaluate the performance of a local spectral model for SOM prediction generated through the spiking strategy. The research was developed in the municipality of Passos, Minas Gerais State, located in the Brazilian Cerrado. Soil samples (0–0.2 m and 0.2–0.4 m depths) were collected in a zigzag pattern and split in calibration of the local models from a test area (90 soil samples) and recalibration and validation from a target area (46 soil samples). After this stage, the SOM contents were determined in a laboratory, and the spectral responses (350–2500 nm) of each soil sample were collected. From the target area, 10, 25 and 50% of soil spectra were selected for recalibration of the local models generated for the test area. Although median results were observed in the post-recalibration, due to the type of sample selected and the relative similarity among the spectral curves of both areas, improvement was observed for all statistical indices, especially when using 50% (23) of samples for recalibration of the local models, reaching r2 = 0.43, RMSEP = 2.34 gdm−3 and RPIQ = 4.58. These results are important for the SOM estimation in the Brazilian Cerrado considering its importance to the food security and socioeconomic activities. However, considering the lack of similar research in the study area, it is necessary to further investigate the development of spectral models on a local scale and their contribution to improve the identification of SOM spatial variability.

A citizen science program to evaluate soil biological quality in urban areas

A citizen science program to evaluate soil biological quality in urban areas

Changes in Enzyme Activities in Salt-Affected Soils during Incubation Study of Diverse Particle Sizes of Rice Straw

Soil enzymes are linked to the plant–soil–enzyme–soil nutrients of the soil system, which play an important role in carbon cycling and phosphorus mineralization in soil. Monitoring soil biological quality, particularly enzyme activities, after receiving organic amendments is a prerequisite for the sustainable management of soils. An incubation study was conducted to evaluate the effect of different particle sizes of rice residue (control, powdered, 1 cm, 2 cm, 5 cm, and 10 cm) on the enzymatic activities in three soils (normal, saline, and sodic). The soils used in the study were alkaline in reaction with a pH range of 7.05–8.86 and an electrical conductivity (EC) gradient from 0.41 to 2.5 dS m−1. Significant changes in the soil enzyme activity (dehydrogenase, fluorescein diacetate, and alkaline phosphatase) were observed with the incorporation of rice residue as compared to control. The enzymatic activities were substantially enhanced with a decrease in the size of the residue up to 28 days during the incubation period. The maximum enzymatic activity in the three soils was found to be in the order of normal > sodic > saline soils. These results suggest that the particle size of rice residues and salt levels should be considered important factors in residue decomposition in soils, as they directly influence the activity of soil enzymes for the overall improvement of the biological pools in soils.

Impact of long-term resource conservation techniques on biogeochemical characteristics and biological soil quality indicators in a rice green-gram farming system.

Nutrient management in resource conservation practices influence the structural and functional microbial diversities and thereby affect biological processes and biochemical properties in soil. We studied the long-term effects of resource conservation technologies on functional microbial diversity and their interactions with soil biochemical properties and enzymatic activities in tropical rice-green gram cropping system. The experiment includes seven treatments viz., conventional practice (CC), brown manuring (BM), green manuring (GM), wet direct drum sowing, zero tillage, green manuring-customized leaf colour chart based-N application (GM-CLCC-N) and biochar (BC) application. The result of the present study revealed that microbial biomass nitrogen (N), carbon (C) and phosphorus (P) in GM practice were increased by 23.3, 37.7 and 35.1%, respectively than CC. GM, BM and GM-CLCC-N treatments provide higher yields than conventional practice. The average well color development value, Shannon index and McIntosh index were significantly higher by 26.6%, 86.9% and 29.2% in GM as compared to control treatment. So, from this study we can conclude that resource conservation practices like GM, GM-CLCC N and BM in combination with chemical fertilizers provide easily decomposable carbon source to support the microbial growth. Moreover, dominance of microbial activity in biomass amended treatments (GM, GM-CLCC N and BM) indicated that these treatments could supply good amount of labile C sources on real time basis for microbial growth that may protect the stable C fraction in soil, hence could support higher yield and soil organic carbon build-up in long run under rice-green gram soil.

Co-culture between Miscanthus x giganteus and Trifolium repens L. to enhance microbial activity, biomass and density in a PAH contaminated technosol

Phytoremediation is a biological soil remediation technique using plants and their associated microorganisms to clean-up contaminated soils and improve soils’ quality. We tested whether a co-culture between Miscanthus x giganteus (MxG) and Trifolium repens L. would enhance the soil biological quality. The objective was to determine the influence of MxG in mono- and in co-culture with white clover on the soil microbial activity, biomass and density. MxG was tested in mono- and in co-culture with white clover in a mesocosm over 148 days. The microbial respiration (CO2 production), the microbial biomass and the microbial density of the technosol were measured. Results showed that MxG induced an increase in microbial activity in the technosol compared to the non-planted condition with the co-culture having a greater impact. Regarding the bacterial density, MxG in mono- and in co-culture significantly increased the 16S rDNA gene copy number. The co-culture increased the microbial biomass, the fungal density and stimulated the degrading bacterial population, contrary to the monoculture and the non-planted condition. We can conclude the co-culture between MxG and white clover was more interesting than MxG monoculture in regards to the technosol biological quality and its potential for PAH remediation improvement.

Influence of Bio-Fertilizer Type and Amount Jointly on Microbial Community Composition, Crop Production and Soil Health

To ensure long-term food production in a changing world, it is critical to identify field management practices that increase crop yields and maintain soil health. Additionally, sustainable agriculture needs to provide experimental evidence to support the use of traditional agricultural practices. In this study, a 20-year investigation of the effects of different combinations of fertilizer types (control, chemical fertilizer, organic fertilizer, and bio-fertilizer) and fertilization amount (conventional dosages and high dosages) on wheat yield and soil health, including soil enzyme activity and microbial biomass, soil microbial diversity, and crop yield. Our long-term study indicates that the use of high dosages of bio-fertilizer can increase the fertilizer yield contribution rate by a minimum of 76.7% compared to other management combinations. Furthermore, this practice can improve soil biological quality, including the concentration of soil microbial biomass carbon, promote bacterial biodiversity, and enhance the soil health index. The effect of high dosages fertilizer was greater than that of conventional dosages fertilizer. The highest soil health index was 0.88 in high dosage bio-fertilizer, and the lowest was 0.12 in chemical fertilizer. In summary, these results suggested that the use of bio-fertilizer can help maintain soil health and crop productivity in the long term.

Effect of Different Arsenic and Biochar Levels on Soil Microbial Population and Enzymatic Activity

Arsenic (As) poses a pervasive environmental contamination problem on a global scale. Human activities have significantly contributed to the extensive presence of arsenic (As) in soils. Recently, there has been growing interest in exploring the potential of biochar in addressing the issue of As-contaminated soils. This study focused on evaluating the effects of two types of biochar, namely straw biochar and iron-modified biochar, on the composition of soil microbial communities and enzymatic activity in soil contaminated with arsenic. After conducting a pot experiment for a duration of 9 months, the microbial communities and enzymatic activity were analyzed. Biochar refers to carbon-rich porous solids that are produced by heating biomasses under low oxygen conditions. These biochars are regarded as environmentally friendly sorbents that can be employed for the treatment of different types of arsenic contamination. The increased abundance of soil microbial populations and the enhanced enzymatic properties suggest that biochar fosters the richness and diversity of bacterial communities. Consequently, these improvements in the soil environment and biological quality highlight the potential of iron-modified biochar as an alternative agent for remediating arsenic-contaminated soils.

Impact of Chemically Diverse Organic Residue Amendment on Soil Enzymatic Activities in a Sandy Loam Soil

To monitor soil biological quality, it is of paramount importance to assess how chemically diverse organic residue amendments reciprocate to organic matter. The present incubation study aimed to evaluate the effect of organic residue amendments varying widely in their biochemical composition on the dynamics of soil enzymatic activity. The changes in the pattern of soil enzymatic activity have been monitored over a period of 63 days using a total of eleven different crop residues. The enzyme activity (dehydrogenase, fluorescein diacetate hydrolysis, acid phosphatase, alkaline phosphatase and phytase) in soils amended with chemically diverse organic residues were significantly higher as compared to the control. It was further observed that the enzymatic activities in Azadirachta indica, Avena sativa and Lens culinaris continued to be higher up to 28 days after their incorporation (DAI). Our study showed that plant residues varying in different cellulose and hemicellulose contents influenced the enzymatic activities as well as functional diversity of soil microbial communities.

Soil microbial community composition and functions are disrupted by fire and land use in a Mediterranean woodland

The intersection of fire, land use transformations, and climate change is putting Mediterranean climate-type ecosystems at risk of soil degradation and loss of ecosystem services. Ondik et al. (2022b) showed that in a Mediterranean dry sclerophyll woodland of South Australia, high severity fire and clearing and grazing practices impacted both physicochemical and biological soil quality indicators. Building upon the work of Ondik et al. (2022b) this study aims to 1) identify soil physicochemical properties impacted by fire and land management that are indirect drivers of changes to soil microbial community composition and 2) determine whether the observed changes to soil microbial community composition affect soil microbial functions. Via a redundancy analysis, we identified fire and management-induced changes to pH, soil water repellency, nutrient stoichiometry, and total nutrient content as significant drivers of the composition of soil microbial communities. We then measured basal respiration, substrate induced respiration, and the carbon mineralisation quotient, and calculated functional trait distributions among microbial communities by linking 16S and 18S rRNA sequences to respiration modes and functional guilds, respectively. We found that fire reduced soil microbial respiration and the relative abundance (RA) of microbial symbionts, anaerobic bacteria, and microaerophilic bacteria, while increasing the RA of aerobic bacteria. Furthermore, management increased the RA of post-fire ectomycorrhizal fungi and may have reduced pathogenic load, microbial efficiency, and wood saprotrophs, while increasing litter, soil, and other saprotrophic species that are adapted to grasslands. This study shows that, through changes to microbial community composition, high severity wildfire and land management affected soil respiration rates, bacterial modes of respiration, prevalence of symbiotic bacteria and fungi, and microbial substrate preference. Having identified the main physicochemical drivers of changes to microbial community composition, we provide valuable insights into how fire and land management can impact soils in Mediterranean woodland.

Linking agricultural diversification practices, soil arthropod communities and soil health

Abstract Soil arthropods comprise a substantial portion of soil biodiversity and regulate processes in the soil ecosystem. Despite this, cropping system diversification designed to improve soil health for agriculture is rarely evaluated for its effects on soil arthropod biodiversity and community structure. As a result, soil arthropods are not usually considered in management decisions. To address this gap, we evaluated the effects of agricultural diversification through rotation on soil arthropods and soil properties using replicated large‐plot field studies representing two climatically distinct agroecological classes (AECs) in the dryland cereal‐growing region of the inland Pacific Northwest, USA. We investigated how different 3‐year annual crop rotations affected soil arthropod biodiversity and community structure. Treatments reflected ‘business‐as‐usual’ rotations in dryland systems and diversified rotations achieved by incorporating novel winter pea (WP) or forage crops (FORs). We also assessed relationships between the Soil Biological Quality index (QBS‐ar), which uses soil arthropods as bioindicators of soil health, and other biological and physiochemical soil health indicators. We collected 710 community samples with 82,509 arthropod specimens across 66 taxa. Novel crops in diversified rotations promoted soil arthropod abundance and biodiversity relative to crops they could replace in rotation. Crop type determined community composition. Most taxa driving differences in community structure were predators and detritivores associated with WP and FORs. In addition to effects on soil arthropods associated with specific crops, effects were also detected across rotations. Incorporating WP into rotations improved QBS‐ar across entire rotations, not just in the WP phases, in both AECs. Links between QBS‐ar and other soil health indicators were complex and varied by AEC. Synthesis and applications: Soil arthropods respond to agricultural diversification and can be used as bioindicators to assess the effects of diversification on soil health. Below‐ground arthropod communities are structured by crop type, suggesting that planting specific crops may promote soil arthropods and their services. We showed that incorporating winter pea and forage crops into dryland cereal rotations supported soil arthropod biodiversity and soil health. Results indicate that soil arthropod assessments can be included in the soil health framework to guide agricultural management decisions.

Arthropod Community Structure Indicating Soil Quality Recovery in the Organic Agroecosystem of Mount Ciremai National Park’s Buffer Zone

<a name="_Hlk128052096"></a><a name="_Hlk128036424"></a><span lang="EN-US">The</span><span lang="EN-US"> Mount Ciremai National Park (TNGC) buffer zone is designed to support conservation efforts. However, agriculture in this area is dominated by conventional farming that excessively uses synthetic fertilizers, which threatens soil quality. Introducing an organic fertilizer and plant growth-promoting rhizobacteria (PGPR) is expected to enhance soil quality recovery in this area. This study aimed to analyze the differences in soil arthropod communities between organic and conventional agriculture and a forest in the TNGC buffer zone to assess soil quality improvement generated by the application of the organic fertilizer and PGPR. Soil arthropods were collected with Berlese-Tullgren funnels and pitfall traps. Several associated environmental parameters, including soil pH, C-organic, temperature, and moisture, were also measured. Data were analyzed using ecological indices (i.e., richness, diversity, evenness, dominance, similarity) and soil biological quality (QBS-ar). Non-metric multidimensional scaling (NMDS) was performed to examine the relation of arthropods with environmental parameters. In total, 957 individuals of soil arthropods belonging to four classes and 15 orders were recorded. Berlese-Tullgren and pitfall traps resulted in a similar tendency in most variables, with higher richness, diversity, and evenness values in the forest, followed by organic and conventional habitats. In addition, similarity and QBS-ar indicated that forest and organic communities were more similar than conventional community. C-organic, soil moisture and pH were considered the most deciding environmental parameters for arthropod assemblages. All measured variables in this study illustrated better soil quality in organic than in conventional agriculture. This study implicates the benefit of utilizing organic fertilizers and PGPR for soil quality restoration in agroecosystems.</span>

Assessment of soil quality in wetlands in Eastern Sicily

Wetlands are of great importance for biodiversity as they support a rich variety of plant and animal species, and the presence of endemic and migratory species is frequent. It is therefore necessary to protect and monitor such areas. The work conducted, reported in the present paper, aimed to verify the quality of soil in most wetlands in eastern Sicily. Specifically, four areas were studied: three Oriented Nature Reserves (RNO), the Saline di Priolo, with the adjacent Penisola di Magnisi, the Saline di Siracusa, and the Faunistic Oasis of Vendicari11The Oasis takes the overall name of Vendicari, in reality it is made up of various localities that take on different names: Vendicari, Marianelli, Cittadella, Calamosche., and one Special Protection Area (SPA), the Biviere di Lentini. The study areas were sampled in 12 different sites, in spring and in autumn, to monitor soil fauna and assess the soil biological quality through the calculation of the QBS-ar. The results represent the first data relating to the QBS-ar in Sicily and, in particular, relating to wetlands.The QBS-ar values recorded were all higher, for both seasons, than the averages reported for land use by Menta et al., 2018. The statistical analysis regarding annual QBS-ar divides the sites into two groups: Saline di Priolo1, Marianelli1, Cittadella1, Vendicari1, Biviere di Lentini2 with a QBS-ar > 200 and Biviere di Lentini1, Saline di Priolo2, Penisola di Magnisi1, Penisola di Magnisi2, Saline di Siracusa1 and Saline di Siracusa2 with QBS-ar < 200; Calamosche1 site show no significant difference between the two groups. Although the number of individuals varied considerably in the two seasons, there are no seasonal differences in the number of taxa and in the QBS-ar.The chemical-physical parameters that influenced the fauna composition and the QBS-ar were mostly those related to the soil texture; some groups were positively correlated with the percentage of silt, while others were negatively correlated with the percentage of sand. The QBS-ar show the same correlations with silt and sand. Proximity or non-proximity to water did not determine variations in the fauna composition and in the QBS-ar values. Soil salinity appeared to be a factor influencing the fauna composition, but further studies are needed to confirm such relief.