World Soil Day (WSD) is held annually on 5 December as a means to focus attention on the importance of healthy soil and to advocate for the sustainable management of soil resources for a food-secure future. The date of 5 December for WSD was chosen because it corresponds with the official birthday of H.M. King Bhumibol Adulyadej, the King of Thailand, who officially sanctioned the event
Soil is home to more than 1/4 of our planet's biodiversity. Yet, we only know 1% of this universe. There are more living creatures in a single teaspoon of healthy soil than there are people on Earth. Soil organisms are responsible for many critical ecosystem processes on which humans depend: from supporting plant growth, to storing carbon and being a vast reservoir for pharmaceuticals.
But soil biodiversity is under threat. Half of the topsoil on the planet has been lost in the last 150 years, with a staggering 26.4 billion tons of soil lost each year, a rate that is 10 times faster than soil is being replenished. Soil erosion is also a significant yet largely overlooked contributor to carbon emissions.
In support of this year's theme - 'Keep soil alive, protect soil biodiversity' - Elsevier presents a curated, open access collection of over 60 journal articles to raise awareness of the importance of maintaining healthy soil ecosystems.
The ploughing-induced compaction of the interface between topsoil and subsoil negatively affects the connectivity and continuity of the complex pore system through plough pans as artificial boundary resulting in water-logged conditions. The conversion of arable land into hayfield is an opportunity for breaking up plough pans and recovering pore networks in the long-term. The basic idea of the current study was to investigate the potential pore structure recovery effect by growing either deep-rooting alfalfa or shallow-rooting grass on former conventionally-tilled cropland.
Common soil characteristics, nutrients and microbial activity at deeper soil depths are topics seldom covered in agricultural studies. Biogeochemical cycles in deep soils are not yet fully understood. This study investigates the effect of different mineral and organic fertilisation on soil organic matter dynamics, nutrients and bacterial community composition in the first meter of the soil profiles in the long-term maize cropping system experiment Tetto Frati, near the Po River in northern Italy.
More meaningful and useful soil health tests are needed to enable better on-farm soil management. Our objective was to assess the relationship between field management, soil health, and soil microbial abundance and composition (phospholipid fatty acid analysis (PLFA)) in soil collected from two fields (farmer-designated ‘good’ versus ‘poor’) across 34 diverse (livestock, grain or vegetable cropping) farms in Maritime Canada.
The rapid global conversion of biodiverse landscapes to intensively managed arable fields may decrease microbial diversity and threaten the long-term fertility of native soils. Previous laboratory and experimental studies provide conflicting results: some have recorded declines in overall microbial diversity and certain beneficial microorganisms under intensified cultivation while others report no change (or even increased) diversity. However, few studies have been carried out in actual agricultural fields.
Soil health is the capacity of soil to function as a vital living system, within ecosystem and land-use boundaries, to sustain plant and animal productivity, maintain or enhance water and air quality, and promote plant and animal health. Anthropogenic reductions in soil health, and of individual components of soil quality, are a pressing ecological concern.
The plant root system influences plant growth and development due to its phenotypic, physiological, metabolomic, and microbiomic traits. Broadly speaking, it is characterized by primary (stem-attached large), secondary (primary-attached medium), and fine (secondary-attached hair-like) roots. The role of root branching order and categories (fine, medium, and large) in influencing microbial communities in the rhizosphere and root environments is not clear.
Salinity stress adversely affects root nodulation symbiotic relationships, and ultimately the nitrogen fixation capacity and the growth and yield of leguminous plants. Improving growth and biological nitrogen fixation of leguminous plants grown on salt–affected soils are considered to be a striking challenge.
This study aimed to characterize endophytic bacteria associated with root-nodules of a wild legume (Genista cinerea: Fabaceae) growing in arid soils of Algeria. A total of ten non-symbiotic endophytic bacterial strains were isolated and identified using a combination of conventional and molecular approaches based on 16S rRNA gene sequencing. Moreover, growth variations of the isolates under different environmental conditions were examined using advanced statistical modeling techniques (Markov Chain Monte Carlo sampler for multivariate generalized linear mixed models-MCMCglmm).
Endophytic fungi were able to protect their host plants against pathogens and promote plant growth. No previous studies have been conducted on the growth promotion of sunchoke by endophytic fungi. This research was the first to characterize plant growth promoting properties of endophytic fungi including, Macrophomina phaseolina BUP2/3 and Diaporthe phaseolorum BUP3/1 isolated from sunchoke and Daldinia eschscholtzii 2NTYL11, Trichoderma koningii ST-KKU1, Trichoderma erinaceum ST-KKU2, Macrophomina phaseolina SS1L10 and Macrophomina phaseolina SS1R10 from medicinal plants.
Plant parasitic nematodes (PPNs) cause huge agricultural and silvicultural losses every year. Most studies that investigated various mechanisms for killing nematodes used the model organism Caenorhabditis elegans. Pseudomonas chlororaphis is an important biocontrol bacterium with great application potential in agriculture. Pseudomonas chlororaphis strains have the potential to control PPNs. In our previous study, we obtained one P. chlororaphis-like bacterium, namely, SPS-41, from the rhizosphere of sweet potato. This strain exhibited wide-spectrum of antifungal activity.
The assessment of microbial functional diversity is an important indicator of soil quality. Different methodological approaches are currently used; among them are enzyme activities (EA) and CLPP (community level physiological profile) techniques (e.g. MicroResp™ MR).
Non-vascular plants such as mosses, lichens and especially microalgae are widespread in terrestrial ecosystems, but their contribution in the nutrient cycling and energy budget of soil food webs is generally neglected. Despite a relatively low total biomass, soil microalgae can be very productive and contribute to the diet of many soil decomposers such as Collembola. Using 15N/14N ratios we showed that phycophagy is of particular importance for Collembola in extreme habitats like rock surfaces, or seasonally during the wintertime.
When biochar (BC) ages in soil, its properties change substantially: cation exchange capacity (CEC), surface area and porosity increase and water repellency decreases, consequently affecting the interactions with soil microorganisms. Activation of BC by organic acids may be regarded as artificial aging. Here, we study the effect of acid-activated BCs on soil microbial enzyme activities (EA) in comparison to several different control treatments without activated BC. A greenhouse pot experiment was conducted using a vineyard soil treated with multiple soil additives (four replications).
Ectomycorrhizal (ECM) fungi are crucial in the functioning of most forest ecosystems. Increased understanding of ECM symbiosis has led to numerous advancements in environment protection and forestry. The ECM fungi are a diverse group, both phylogenetically and functionally. Research covering their community structure on distinct sites shows that the presence of certain taxa depends on particular stand traits, such as tree species and age structure.
Plant diversity was shown to influence the N cycle, but plant diversity effects on other nutrients remain unclear. We tested whether plant species richness or the presence/absence of particular functional plant groups influences P partitioning among differently extractable pools in soil, P concentrations in soil solution, and exploitation of P resources (i.e.
In many tropical regions, such as New Caledonia, soil erosion from anthropogenic activities and subsequent ecological restoration are major issues that require detailed soil and vegetation data for the production of management plans. To determine if some plant species are more useful for stabilizing soil aggregates and thus reducing erodibility, we examined three species endemic to New Caledonia, and measured how root traits and associated mycorrhizas and fungi influenced Ferralsol aggregate stability (MWD).
This study assessed the carbon (C) budget and the C stocks in major compartments of the soil food web (bacteria, fungi, protists, nematodes, meso- and macrofauna) in an arable field with/without litter addition. The C stocks in the food web were more than three times higher in topsoil (0–10 cm) compared to subsoil (>40 cm). Microorganisms contained over 95% of food web C, with similar contributions of bacteria and fungi in topsoil. Litter addition did not alter C pools of soil biota after one growing season, except for the increase of fungi and fungal feeding nematodes in the topsoil.
It has long been established that the spatial scale of inquiry affects the ecological patterns that are revealed. However, studies of the ecological drivers underlying the assembly of soil animal communities rarely adopt a multi-scale perspective. Here, we quantified the distribution of oribatid richness along a chronosequence of temperate hardwood forests in a deglaciated region of eastern North America and analyzed variation in oribatid community structure at two grain sizes: 0.1 m2 and 900 m2, and two spatial extents: 20–150 m and 80–420 km.
It is commonly acknowledged that ants improve the hydraulic properties of soils in which they build their nests. To date, however, most studies of such soil modifications have focused on one ant species and one type of ecosystem, rather than investigating how different ant species affect different types of land cover within the same landscape. Our study focused on modifications to water infiltration and surface texture of Haplic Luvisols by two ant species—one of them present only in a forest and the other present only in a pasture.
The biochemical effects of trees may significantly influence local pedogenesis as well as pedocomplexity, biodiversity and forest dynamics on both stand and landscape scales. One such effect is the decay of tree trunks, which is driven by organisms, and especially by the microbiome. Decomposition modifies soil formation, which due to the existence of many feedbacks affects the composition of the decomposer community.
Over the last two decades, there has been growing interest on the effects of agricultural practices on soil biology in Europe. As soil biota are known to fluctuate throughout the season and as agro-environmental conditions may influence the effect of agricultural practices on soil organisms, conclusions cannot be drawn from a single study. Therefore, integrating the results of many studies in order to identify general trends is required. The main objective of this study was to investigate how soil biota are affected by repeated applications of organic amendments (i.e.
Elucidating relationships between the soil food web, soil processes, and agroecosystem function is a critical step toward a more sustainable agriculture. Soil and crop management practices can alter these relationships, and their effects can persist even after imposing new management practices. In 2005, the Cornell Organic Grain Cropping Systems Experiment was established in central New York. Four cropping systems that varied in fertilizer inputs, tillage practices, and weed control were compared: High Fertility, Low Fertility, Enhanced Weed Management, Reduced Tillage.
Land-use intensification at the field and landscape scale is a strong driver for declining biodiversity and ecosystem service provision. Vineyards are characterised by non-productive inter-rows, which could potentially host diverse plant communities. Mulching, tillage or herbicides are used to mitigate the competition between vines and the inter-row vegetation.
Annelids (Lumbricidae and Enchytraeidae) and nematodes are common soil organisms and play important roles in organic matter decomposition, nutrient cycling and creation of soil structure and porosity. However, these three groups have rarely been studied together and only few studies exist for urban soils.
Many studies have investigated whether microbiota has been adapted to decompose a given litter type but we have limited information about the specific role of microarthropods in litter decaying processes. This experiment studied functional redundancy of microarthropods in a litter decomposition system by interchanging mesofauna among three different litter types. The study hypothesized that total microarthropod densities would be lower in foreign litter type than in original ('home') litter; and litter with foreign mesofauna would decompose slower than with native one.
Recent perspective has highlighted the microbial importance of interplay between catabolic breakdown and anabolic synthesis in influencing soil organic carbon (SOC) dynamics and persistence. However, studies on these contrasting activities remain rare, despite value to global discussions on economic and ecologically sustainable ecosystem management. Here we investigate microbial response in a no-till farm in Northeast China after an 8-year manipulation of plant residue returns of varying quantity including control (0%, NT0), low (33%, NT33), medium (67%, NT67) and high (100%, NT100).
Previous studies already demonstrated that biochar addition reduces nitrogen (N) leaching in soil, but little information is available about its effects on N leaching and bacterial community structure under the application of organic N. This study investigated the effects of corn-straw biochar under the application of urea (250 kg N ha-1) in layered soil columns. The PCR-amplified partial 16S rRNA genes in soil were sequenced before and after biochar treatment in order to assess the change of bacterial diversity and community structure utilizing the Illumina technology.
Climate change is modifying global biogeochemical cycles. Microbial communities play an integral role in soil biogeochemical cycles; knowledge about microbial composition helps provide a mechanistic understanding of these ecosystem-level phenomena. Next generation sequencing approaches were used to investigate changes in microbial functional groups during ecosystem development, in response to climate change, in northern boreal wetlands.
Manual chamber-based measurements of CO2 (and H2O) fluxes are important for understanding ecosystem carbon metabolism. Small opaque chambers can be used to measure leaf, stem and soil respiration. Larger transparent chambers can be used to measure net ecosystem exchange of CO2, and small jars often serve this purpose for laboratory incubations of soil and plant material. We developed an Android application (app), called Flux Puppy, to facilitate chamber-based flux measurements in the field and laboratory.
One mechanism by which land use change influences biodiversity and ecological processes is through changes in the local climate. Here, the relationships between leaf area index and five climate variables - air temperature, relative humidity, vapour pressure deficit, specific humidity and soil temperature - are investigated across a range of land use types in Borneo, including primary tropical forest, logged forest and oil palm plantation.
The net ecosystem exchange (NEE) is the difference between ecosystem CO2 assimilation and CO2 losses to the atmosphere. Ecosystem respiration (Reco), the efflux of CO2 from the ecosystem to the atmosphere, includes the soil-to-atmosphere carbon flux (i.e., soil respiration; Rsoil) and aboveground plant respiration. Therefore, Rsoil is a fraction of Reco and theoretically has to be smaller than Reco at daily, seasonal, and annual scales.
Soils host the vast majority of life on Earth including microorganisms and animals, and supporting all terrestrial vegetation. While soil organisms are pivotal for ecosystem functioning, the assemblages of different biota from a taxonomic and functional perspective, as well as how these different organisms interact, remains poorly known. We provide a brief overview of the taxonomic and functional diversity of all major groups of soil biota across different scales and organism sizes, ranging from viruses to prokaryotes and eukaryotes.
Non-ribosomal peptides (NRPs) and polyketides (PKs) are among the most profuse families of secondary metabolites (SM) produced by bacteria. These compounds are believed to play an important ecological role in microbe-microbe and microbe-plant interactions in soil and roots microbiomes. Over the years, screening of NRPs and PKs in soil bacteria has resulted in high rates of rediscovery, mainly due to challenges associated with bacterial isolation.
Fire is an ecological disturbance that alters soil microbiomes and the functions they mediate in terrestrial ecosystems. Soil microbial diversity in Mediterranean Basin ecosystems shows resilience to fire following the restoration of plant-soil feedbacks. We hypothesised that microbial functions related to organic matter decomposition and nutrient cycling might show similar patterns of recovery.
Non-target effects of deliberately released organisms into a new environment are of great concern due to their potential impact on the biodiversity and functioning of ecosystems. Whereas these studies often focus on invasive species of macro-organisms, the use of microbial inoculants is often expected to have specific effects on particular functions but negligible overall effects on resident microbial communities. Here, we posit that such introductions often impact native microbial communities, which might influence ecosystem processes.
Improving rice yield potential is crucial for global food security. Taoyuan, China, is famous worldwide as a special ecosite for ultrahigh rice yield. Climatological factors affecting this phenomenon have been identified, but the potential molecular processes and environmental mechanisms promoting ultrahigh yield remain mysteries.
Urbanisation involves major changes in environmental conditions such as light, temperature, humidity and noise levels, but the effect of urbanisation on soil conditions and soil biodiversity has received less attention. The reported effects on species richness across a rural to urban landscapes are not unequivocal. Positive, negative and neutral effects have been found, but what is causing this ambiguity in the relationship between species richness and urbanisation is poorly understood.
Produced water (PW) is the main waste stream generated from oil and gas extraction. Nowadays, half of the global PW volume is managed through environmentally controversial and expensive disposal practices, such as re-injection through deep wells. In dry areas such as in the Arabian Peninsula, PW could be reused to irrigate crops, creating environmental, economic and social value. However, the quality of most PWs remains challenging as their high salinity, sodicity and alkalinity can degrade soil fertility and crop yield.
With ongoing global climate change and human activities, increasing desertification plays a predominant role in increasing soil nutrient losses. Soil nitrogen (N) is the essential limiting nutrient supporting plant growth and evaluating soil nutrient content, especially in desert ecosystems. N microbial processes will ultimately restore and maintain the balance in the soil N cycle, but the damage caused by desertification to soil N functional microorganisms associated with N supply, transformation, and loss is poorly understood.
This study investigates the ostracod assemblages obtained from a sediment core from a paleolake in the Sağlık plain in south-central Anatolia (Turkey). In addition to ostracods, oxygen and. carbon stable isotopes of ostracod shells were analysed and pollen analysis of the core undertaken. The sediments comprise the Late Glacial and early Holocene interval with an approximate 14C age from 18,000 to 6700 14C years ago, after applying a correction for reservoir effects. Eight podocopid ostracod species were recorded, among them Cyprideis torosa and Candona sp.
In limestone quarries, after quarry abandonment, ecological restoration takes place subsequently over several years, often with the use of different procedures and backfilling materials. The success of the different restoration actions performed at a limestone quarry (Colle Pedrino, Lombardy Prealps, Italy) in terms of vegetation cover and biodiversity levels, compared to the surrounding natural areas, was evaluated in this work.
As an important component of global change, plant invasion threaten the sustainability of global ecosystems and may alter the carbon dynamics in the invaded area. Knowledge of the effects of Spartina alterniflora invasion on soil organic carbon (SOC) and soil inorganic carbon (SIC) stocks and their profile distribution is limited in coastal salt marshes, which are referred as important “blue carbon” ecosystems. A short-term invasion chronosequence of 2–10 years was used to evaluate the responses of SOC and SIC over the invasion period in the Yellow River Estuary, China.
This research examines high-elevation biocrusts on volcanic tephra in Haleakalā Crater, Maui, Hawai′i; geomorphic, ecological, and pedological processes are discussed, in order to provide an integrated geoecological view of linkages that have influenced biocrust genesis. The study considers four spatial scales: (i) the landscape scale; (ii) the site scale; (iii) the miniature scale and, (iv) the microscopic scale.
Although the effects of nitrogen (N) fertilization on soil microflora have been well studied, the effects should be verified across soil types and N-added levels. To understand the impacts of N fertilization on shifts in soil biological traits and bacterial communities and to further explore the coupling mediation of these parameters with respect to crop yields, we sampled soils from three experimental sites (each site received three levels of N fertilization (0, 168 and 312 kg N ha−1)) that share the same climatic conditions but have different soil types (clay, alluvial and sandy soils).
At the 21st session of the United Nations Framework Convention on Climate Change (UNFCCC, COP21), a voluntary action plan, the ‘4 per 1000 Initiative: Soils for Food Security and Climate’ was proposed under the Agenda for Action. The Initiative underlines the role of soil organic matter (SOM) in addressing the three-fold challenge of food and nutritional security, adaptation to climate change and mitigation of human-induced greenhouse gases (GHGs) emissions. It sets an ambitious aspirational target of a 4 per 1000 (i.e.
The no-tillage system combining winter cover crops and crop rotation may increase the efficiency use of soil P and phosphate fertilizer. The objective of this study was to evaluate the effect of three decades of different soil management systems and winter cover crops on the fractions of P in a clayey Oxisol of Paraná State, Brazil. The bi-factorial experiment with three replicates was established in 1986. The main plots consisted of seven winter cover crops. In the subplots, two tillage systems were used: no-tillage and conventional tillage.
Multiple nutrient deficiencies related to severe soil fertility depletion have emerged as the major constraint to the sustainability of agriculture on a global scale. Use of biochar and biochar-compost mixtures from different alternative organic sources have been proposed as an option for improving soil fertility, restoring degraded land, and mitigating the emissions of greenhouse gasses associated with agriculture.
Irrigation management may influence soil greenhouse gas emissions (GHG). Solid-set sprinkler irrigation systems allow to modify the irrigation time and frequency. The objective of this study was to quantify the effect of two irrigation times (daytime, D; nighttime, N)and two irrigation frequencies (low, L; high, H)on soil carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O)emissions in a solid-set sprinkler-irrigated maize (Zea mays L.)field located in NE Spain during 2015 and 2016 growing seasons and the fallow period between growing seasons.
Climate change and population growth generates a decrease in water availability around the world which can compromise the maintenance of sustainable agriculture. Thus, treated wastewater (TWW) became an alternative to minimize water shortage. However, this may indirectly affect the soil's microbial properties. In this study different soils irrigated for 0, 1, 8 and 20 years with TWW were sampled and from the east central region of Tunisia.
Water harvesting techniques have shown promising outcomes in mitigating risks, increasing yields and delivering positive influences on other ecosystems. A field study was conducted in Northern Jordan to assess the influence of combined in-situ water harvesting techniques, micro-catchment and mulching on soil moisture content, plant morphology, gas exchange [photosynthesis (Pn), transpiration (E), and stomatal conductance (gs)] and midday stem water potential (Ψsmd) of young pistachio (Pistacia vera cv. Ashori) trees.
Soil and water salinity and associated problems are a major challenge for global food production. Strategies to cope with salinity include a better understanding of the impacts of temporal and spatial dynamics of salinity on soil water balances vis-à-vis evapotranspiration (ET) and devising optimal irrigation schedules and efficient methods. Both steady state and transient models are now available for predicting salinity effects on reduction of crop growth and means for its optimization.
Viticulture is a valuable sector worldwide with an extraordinary socio-economic impact in Spain. Numerous pests and diseases threaten vineyards, and their management primarily relies on the use of conventional agrochemicals. The current paradigm of sustainability pursues the implementation of ecologically sound strategies in vineyard ecosystems. The use of cover crops is arising as an alternative with numerous benefits, including favoring above-belowground biodiversity and the presence of beneficial soil organisms such as the entomopathogenic nematodes (EPNs).
The diversification of tropical pastures with legumes (trees) for increased forage and animal productivity has been advocated. Nevertheless, effects on soil quality and belowground biodiversity, and the implications for sustainable intensification remain poorly documented, particularly when cattle grazing is included in the study. We evaluated the impact of forage system diversification with herbaceous and woody legumes on soil properties and soil macrofauna communities and their spatial heterogeneity in a three-year-old field trial in Cauca Valley, Colombia.
Agroecosystems make up a significant portion of terrestrial ecosystems and receive a disproportionally high amount of terrestrial nitrogen inputs from fertilizer, leading to nitrogen loss and associated environmental problems. Integrated crop livestock systems, such as pasture-integrated crop rotations, may be more environmentally sustainable however the long-term effects of this management practice on soil microorganisms and nitrogen transformations are not well understood.
Critical knowledge gaps about environmental fate and unintentional effects of currently used pesticides (CUPs) hamper the understanding and mitigation of their global impacts on ecological processes. We investigated the exposure of earthworms to 31 multiclass CUPs in an arable landscape in France. We highlighted the presence of at least one pesticide in all soils (n = 180) and 92 % of earthworms (n = 155) both in treated crops and nontreated habitats (hedgerows, grasslands, and cereals under organic farming).
Anthropogenic climate change is altering the functioning of terrestrial ecosystems. Agricultural systems are particularly vulnerable to climate change as they are frequently disturbed by intensified management practices. This also threatens belowground organisms that are responsible for providing crucial ecosystem functions and services, such as nutrient cycling and plant disease suppression. Amongst these organisms, earthworms are of particular importance as they can modulate the effects of climate change on soil organisms by modifying the biotic and abiotic soil conditions.
As a response to the worldwide challenge raised by soil degradation, Conservation Agriculture (CA) was proposed to help restoring the three main soil functions, i.e. carbon transformation, nutrient cycling and structure maintenance. However, there is still a lack of integrative studies that assess the overall impact of CA on soil health. To fill the gap, Biofunctool®, a set of in-field indicators, was developed to monitor changes in soil biological functioning.
Soil organic matter (OM) stratification and macro and micro fauna are both good indicators for the evaluation of soil ecological functioning, which is interrelated with nutrient cycles. To the best of the authors’ knowledge, responses of the degree of OM stratification with soil depth expressed as a ratio, and belowground biota to forest degradation and land cover changes have received little attention, particularly in northern Iran.
Historically, tillage has been essential for seedbed preparation and weed control, but it has also accelerated soil degradation through erosion and loss of soil organic matter (SOM). Our objective was to quantify the changes in soil physical properties and earthworm abundance under six tillage treatments on an Endocalcic Chernozem (Loamic) soil (2016 and 2017).
The artificial drainage of heavy textured gley soils is prevalent on pasture. Drainage of a soil profile reduces the water filled pore space (WFPS) in the upper soil horizons with consequences for N2 and N2O emissions, the fate of nitrogen (N), transformational processes and microbial and bacterial communities. The present intact soil column study with isotopically enriched fertiliser investigates all these aspects simultaneously under two WFPS treatments (80% (HS) and 55% (LS) saturation).