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Soils provide habitat, regulation and utilization functions. Therefore, Germany aims to reduce soil sealing to 30 ha day - 1 by 2030 and to eliminate it by 2050. About 55 ha day - 1 of soil are damaged (average 2018–2021), but detailed information on its soil quality is lacking. This study proposes a new approach using geo-information and remote sensing data to assess agricultural soil loss in Lower Saxony and Brandenburg. Soil quality is assessed based on erosion resistance, runoff regulation, filter functions, yield potential and the Müncheberg Soil Quality Rating from 2006 to 2015. Data from the German Soil Map at a scale of 1:200,000 (BÜK 200), climate, topography, CORINE Land Cover (CLC) and Imperviousness Layer (IMCC), both provided by the Copernicus Land Monitoring Service (CLMS), are used to generate information on soil functions, potentials and agricultural soil loss due to sealing. For the first time, soil losses under arable land are assessed spatially, quantitatively and qualitatively. An estimate of the qualitative loss of agricultural soil in Germany between 2006 and 2015 is obtained by intersecting the soil evaluation results with the quantitative soil loss according to IMCC. Between 2006 and 2015, about 73,300 ha of land were sealed in Germany, affecting about 37,000 ha of agricultural soils. This corresponds to a sealing rate of 11 ha per day for Germany. In Lower Saxony and Brandenburg, agricultural soils were sealed at a rate of 1.9 ha day - 1 and 0.8 ha day - 1 respectively, removing these soils from primary land use. In Lower Saxony, 75% of soils with moderate or better biotic yield potential have been removed from primary land use, while in Brandenburg this figure is as high as 88%. Implementing this approach can help decision-makers reassess sealed land and support Germany’s sustainable development strategy. [ABSTRACT FROM AUTHOR]

Biostimulants are gaining prominence in scientific research, with the potential to enhance plant productivity through benefits to crop yield/quality and tolerance to environmental stresses. Through possible improvements to nutrient use efficiency, they may also lessen the adverse environmental impacts of conventional inorganic fertilizer use in agriculture. The application of biostimulants is currently uncommon as a farming practice, with uncertain effectiveness in delivering these potential benefits. Current research focuses on biostimulant effects on plant physiological changes. There is little scientific evidence on the impact of biostimulants on soil properties (biological, physical, or chemical) or soil functions. This knowledge gap should be addressed considering the vital role of soil processes in the bioavailability of nutrients, as reflected in crop productivity. This review evaluates laboratory and field experimental work on the effectiveness of common, non-microbial biostimulants, with a focus on their modes of action within the soil matrix. Of 2,097 initial articles returned through the search strings, 10 were within the scope of this review. A common soil biostimulant mechanism emerges from this literature. This relates to the supply of nutrients provided by the biostimulants, which stimulate native soil microbiology in mineralizing organic material in the soil, thus producing more bioavailable nutrients for plant uptake. Additionally, some articles link biostimulant effects to soil physical and chemical changes, which in turn impact soil biology (and vice versa). However, there is inconsistent evidence to provide full support for these explanatory mechanisms. This review highlights the need for further research into the effect of biostimulants on the native soil microbiology and associated soil properties, to provide greater clarity on biostimulants' modes of action and greater mechanistic insights into how they can be used to improve crop production. [ABSTRACT FROM AUTHOR]

Biostimulants are gaining prominence in scientific research, with the potential to enhance plant productivity through benefits to crop yield/quality and tolerance to environmental stresses. Through possible improvements to nutrient use efficiency, they may also lessen the adverse environmental impacts of conventional inorganic fertilizer use in agriculture. The application of biostimulants is currently uncommon as a farming practice, with uncertain effectiveness in delivering these potential benefits. Current research focuses on biostimulant effects on plant physiological changes. There is little scientific evidence on the impact of biostimulants on soil properties (biological, physical, or chemical) or soil functions. This knowledge gap should be addressed considering the vital role of soil processes in the bioavailability of nutrients, as reflected in crop productivity. This review evaluates laboratory and field experimental work on the effectiveness of common, non-microbial biostimulants, with a focus on their modes of action within the soil matrix. Of 2,097 initial articles returned through the search strings, 10 were within the scope of this review. A common soil biostimulant mechanism emerges from this literature. This relates to the supply of nutrients provided by the biostimulants, which stimulate native soil microbiology in mineralizing organic material in the soil, thus producing more bioavailable nutrients for plant uptake. Additionally, some articles link biostimulant effects to soil physical and chemical changes, which in turn impact soil biology (and vice versa). However, there is inconsistent evidence to provide full support for these explanatory mechanisms. This review highlights the need for further research into the effect of biostimulants on the native soil microbiology and associated soil properties, to provide greater clarity on biostimulants' modes of action and greater mechanistic insights into how they can be used to improve crop production. [ABSTRACT FROM AUTHOR]

Essential soil functions such as plant productivity, C storage, nutrient cycling and the storage and purification of water all depend on soil biological processes. Given this insight, it is remarkable that in modeling of these soil functions, the various biological actors usually do not play an explicit role. In this review and perspective paper we analyze the state of the art in modeling these soil functions and how biological processes could more adequately be accounted for. We do this for six different biologically driven processes clusters that are key for understanding soil functions, namely i) turnover of soil organic matter, ii) N cycling, iii) P dynamics, iv) biodegradation of contaminants v) plant disease control and vi) soil structure formation. A major conclusion is that the development of models to predict changes in soil functions at the scale of soil profiles (i.e. pedons) should be better rooted in the underlying biological processes that are known to a large extent. This is prerequisite to arrive at the predictive models that we urgently need under current conditions of Global Change. [ABSTRACT FROM AUTHOR]

Whether soil structure should be viewed mostly as a system of pores or a set of aggregates is a question soil scientists keep debating in the literature, but it is unclear whether the wider soil science community is also divided. In a quick survey among mainly German soil scientists of all career levels and sub‐disciplines, most participants agreed that both pores and aggregates are important to describe soil structure. The debate can nevertheless be fruitful if it is led more efficiently, avoiding generalisations, misunderstandings and potential emotional barriers. [ABSTRACT FROM AUTHOR]

Halophyte-based remediation emerges as a novel strategy for ameliorating saline soils, offering a sustainable alternative to conventional leaching methods. While bioremediation is recognized for its ability to energize soil fertility and structure, the complex interplays among plant traits, soil functions, and soil microbial diversity remain greatly unknown. Here, we conducted a 5-year field experiment involving the continuous cultivation of the annual halophyte Suaeda salsa in saline soils to explore soil microbial diversity and their relationships with plant traits and soil functions. Our findings demonstrate that a decline in soil salinity corresponded with increases in the biomass and seed yield of S. salsa, which sustained a consistent seed oil content of approximately 22% across various salinity levels. Significantly, prolonged cultivation of halophytes substantially augmented soil microbial diversity, particularly from the third year of cultivation. Moreover, we identified positive associations between soil multifunctionality, seed yield, and taxonomic richness within a pivotal microbial network module. Soils enriched with taxa from this module showed enhanced multifunctionality and greater seed yields, correlating with the presence of functional genes implicated in nitrogen fixation and nitrification. Genomic analysis suggests that these taxa have elevated gene copy numbers of crucial functional genes related to nutrient cycling. Overall, our study emphasizes that the continuous cultivation of S. salsa enhances soil microbial diversity and recovers soil multifunctionality, expanding the understanding of plant-soil-microbe feedback in bioremediation. IMPORTANCE The restoration of saline soils utilizing euhalophytes offers a viable alternative to conventional irrigation techniques for salt abatement and soil quality enhancement. The ongoing cultivation of the annual Suaeda salsa and its associated plant traits, soil microbial diversity, and functionalities are, however, largely underexplored. Our investigation sheds light on these dynamics, revealing that cultivation of S. salsa sustains robust plant productivity while fostering soil microbial diversity and multifunctionality. Notably, the links between enhanced soil multifunctionality, increased seed yield, and network-dependent taxa were found, emphasizing the importance of key microbial taxa linked with functional genes vital to nitrogen fixation and nitri fication. These findings introduce a novel understanding of the role of soil microbes in bioremediation and advance our knowledge of the ecological processes that are vital for the rehabilitation of saline environments. [ABSTRACT FROM AUTHOR]

Acid rain and invasive plants have quintessential adverse impacts on terrestrial ecosystems. As an environmentally safe method for disposal of invasive plants, we tested the effect of biochar produced from these plants in altering soil deterioration under acid rain as compared with lime. Given the impacts of the feedstock type and soil properties on the response of soil to the added biochar, we hypothesized that the microbial community and functions would respond differently to the charred invasive plants under acid rain. A pot experiment was conducted to examine the response of soil microbiomes and functions to the biochar produced from Blackjack (Biden Pilosa), Wedelia (Wedelia trilobata), and Bitter vine (Mikania micrantha Kunth), or quicklime (CaO) at a rate of 1 % (w/w) under acid rain. Like soil pH, the nutrient contents (nitrogen, phosphorus, and potassium), calcium, and cation exchange capacity (CEC) were important as dominant edaphic factors affecting soil microbial community and functionality. In this respect, lime decreased nutrients availability, driven by 11-fold, 44 %, and 2-fold increments in calcium content, pH, and C/N ratio. Meanwhile, biochar improved nutrients availability under acid rain owing to maintaining a neutral pH (∼6.5), increasing calcium (by only 2-fold), and improving CEC, water repellency, and aggregation while decreasing the C/N ratio and aluminum content. Unlike biochar, lime decreased the relative abundance of Nitrosomonadaceae (the dominant ammonia-oxidizing bacteria) while augmenting the relative abundance of some fungal pathogens such as Spizellomycetaceae and Sporormiaceae. Given the highest nitrogen and dissolved organic carbon content than other biochar types, Wedelia-biochar resulted in the greatest relative abundance of Nitrosomonadaceae; thus, the microbial carbon and nitrogen biomasses were maximized. This study outlined the responses of the soil biogeochemical properties and the related microbial community structure and functionality to the biochar produced from invasive plants under acid rain. This study suggests that biochar can replace lime to ameliorate the effects of acid rain on soil physical, chemical and biological properties.

Digital soil mapping (DSM) relies on machine-learning and geostatistics to represent soil property observations across space. DSM techniques are powerful but often empirical, being limited to the quality and density of point samples. Water dynamics are closely related to soil variability, and the physics that govern water movement are well known. Hydrological properties can hence be simulated by physical models through space and time, unveiling key characteristics about soils. We propose the use of hydrologic models to map soils across the surface (2D), depth (1D), and time (1D)–which provides a 4D approach to digital soil mapping (4DSM). The Distributed Hydrology Soil Vegetation Model (DHSVM) was applied to a watershed currently under pasture. Moisture sensors and wells were installed at different depths in the watershed on summit, sideslope and toeslope positions to validate the model. DHSVM simulations of soil moisture distribution and depth to saturation were performed during the hydrological year (October 2008-September 2009). Clusters of similar pixels based on soil moisture values were determined using Dynamic Time Warping (DTW) to align temporal data and K-means. Clustering was performed both seasonally and for the entire year. Temporal patterns simulated by DHSVM matched measurements given by moisture sensors and wells. Seasonal clusters differed from the annual cluster. Distinct clusters were observed for each season and with depth, showing that spatiotemporal soil variability is lost when statically assessing soils. Spatiotemporal clusters corroborated field observations of fragipan occurrence not explicitly spatially mapped by Soil Survey Geographic Database (SSURGO). If a connection can be made between water and soils, static and dynamic soil variability can be predicted using physically based hydrologic models. Hydrologic models can benefit soil mapping by enabling reliable 4D simulation of water dynamics, which are fundamental to soil variability and soil classification and directly relate to biological, physical and chemical soil processes not captured by typical soil sampling protocols.

Although crop conversion from annual to perennial crops has been considered as one path towards climate-smart and resource-efficient agriculture, the effects of this conversion on soil multifunctionality and biomass yields remain unclear. The objective of the study is to enhance soil multifunctionality while exerting a marginal influence on farmer income. Here, we investigated the effects of annual winter wheat (Triticum aestivum L.) and two perennial crops (a grass (Lolium perenne L.), a legume (Medicago sativa L.), and their mixture) on soil multifunctionality and biomass yield on the Yellow River floodplain. Soil multifunctionality was assessed by the capacity of water regulation and the multifunctionality of carbon (C), nitrogen (N), and phosphorus (P) cycles. C cycle multifunctionality index is the average of β-xylosidase, β-cellobiosidase, and β-1, 4-glucosidase. N cycle multifunctionality index is the average of L-leucine aminopeptidase and β-1, 4-N-acetyl-glucosaminidase, and acid phosphatase represented (and dominated) P cycle functions. The results showed that perennial crops enhanced soil multifunctionality by 207% for L. perenne, 311% for M. sativa, and 438% for L. perenne + M. sativa, compared with annual winter wheat (T. aestivum). The effect of perennial crops on soil multifunctionality increased with infiltration rate, dissolved organic C, microbial biomass C, and extracellular enzymatic activities for both C and N acquisition. However, we observed that perennial crops had a lower biomass yield than annual crop. Therefore, the transition of agricultural landscapes to perennials needs to take into account the balance between environmental protection and food security, as well as environmental heterogeneity, to promote sustainable agricultural development. [ABSTRACT FROM AUTHOR]

The aim of the study was to assess the impact of the specialization of agricultural production on selected parameters of soil health, i.e., soil organic carbon content (SOC), soil acidification, soil nutrient status, i.e., total nitrogen content (NT), available forms of phosphorus, potassium, and magnesium, and microelements content, as well as the content of selected potentially toxic metals (PTMs). For the study, 18 farms located in the Masovian Voivodeship in Central Poland were selected. They were grouped into six types, and each type was represented by three farms. The study included organic farms; farms specializing in: crop, vegetable, poultry, dairy cattle, and pigs production. A total of 144 soil samples were analyzed. The results showed that the specialization of agricultural production and fertilizer management had a significant impact on most of the tested soil health parameters, except SOC and NT content. Despite the high organic fertilizer doses introduced into soils in poultry (170 kg N per hectare as poultry manure) and pig farms (150 kg N per hectare as pig manure), there was no significant influence of these amendments on SOC content. This may indicate low organic carbon sequestration potential in some Polish agricultural soils. Organic farms had the lowest levels of plant nutrients in the tested soil samples, which may limit soil productivity. All the tested soils were strongly acidified, which could restrict both production and regulatory soil functions. Based on the synthetic index of soil fertility (SSFI), vegetable and poultry farms were characterized by very high fertility, while crop, dairy cattle, and pig farms fell into the medium fertility class. Organic farms were in the lowest fertility class. However, the study suggests that the SSFI may not be the best indicator for assessing soil fertility and health; therefore, further research is needed. [ABSTRACT FROM AUTHOR]

Introduction: Forage culture is a common way to restore degraded grasslands and soil functions, in which the reconstruction of the soil microbial community and its relationship with extracellular enzyme activity (EEAs) can characterize the recovery effects of degraded grasslands. However, the impacts of forage culture on the interaction between soil microbes and EEAs and whether the recovery effect of soil functions depends on the varying degradation statuses remain unclear. Methods: We conducted a plantation of a dominant grass, Leymus chinensis, in the soil collected from severe, moderate, light, and non-degradation statuses in the Songnen grassland in northeastern China. We measured soil microbial diversity and soil EEAs, and predicted microbial functional groups using FUNGuild. Results: The results showed that L. chinensis culture promoted soil bacterial alpha diversity and soil EEAs only in the moderate degradation status, indicating a dramatic dependence of the recovery effects of the grass culture on degradation status of the grassland. After planting L. chinensis for 10weeks, a decreasing trend in the chemoheterotrophy and nitrate-reduction microbial functional groups was found. In contrast, the abundance of the nitrogen (N)-fixing microbial functional group tended to increase. The positive correlation between soil EEAs and the nitratereduction and N-fixing microbial functional groups was enhanced by planting L. chinensis, indicating that grass culture could promote soil N cycle functions. Conclusion: We illuminate that grass culture may promote the restoration of soil functions, especially soil N cycling in degraded grasslands, and the recovery effect may depend on the grassland degradation status. We emphasized that selection of the plant species for restoration of grasslands needs to consider the restoration effects of microbial functional groups and soil functions. [ABSTRACT FROM AUTHOR]

A failure to select a suitable location to grow organic coffee translates into low plantation productivity and degradation of such agroecosystems. Therefore, we need to know a priori the suitable environmental conditions. Twenty-eight soil profiles were described in this study in the Mixteca Alta, Oaxaca. Physical and chemical properties were measured, and a regression model approach identified the main properties associated with the peasant perception of soil suitability for organic coffee production. We found that peasant perception of high soil suitability is in altitudes higher than 1400 masl, soil depth greater than 1 m, slightly basic condition in its maximum pH value, 0.4 to 1 dS m−1 of Electric Conductivity at its maximum, and low values of Na. [ABSTRACT FROM AUTHOR]

The identification of societal impacts resulting from interdisciplinary research is a complex task. This complexity is particularly evident for agricultural research, which strives to mitigate trade-offs between agricultural production and multiple societal targets, including food provision, ecosystem services, soil and biodiversity conservation, climate action and rural development, all contributing to the Sustainable Development Goals (SDGs). To address this issue, this article presents an Impact Mapping Framework for systematically assessing such societal impacts. The use case on soil health shows how ZALF, an interdisciplinary agricultural landscape research institute in Germany, uses the framework to map its research activities and their contributions towards the improvement of ecosystem services and biodiversity, and the SDGs. The Impact Mapping Framework is presented in a circular format, with research activities mapped in the outermost circle and their contributions to SDGs in the center. The article provides step-by-step instructions for applying the impact mapping framework and a supplementary Impact Map Table. It concludes by emphasizing the importance of using a systemic approach to formatively assess the societal impact of interdisciplinary research, to visualize it for external communication, to identify research gaps and collaboration opportunities, and to build impact literacy.

Biostimulants are gaining prominence in scientific research, with the potential to enhance plant productivity through benefits to crop yield/quality and tolerance to environmental stresses. Through possible improvements to nutrient use efficiency, they may also lessen the adverse environmental impacts of conventional inorganic fertilizer use in agriculture. The application of biostimulants is currently uncommon as a farming practice, with uncertain effectiveness in delivering these potential benefits. Current research focuses on biostimulant effects on plant physiological changes. There is little scientific evidence on the impact of biostimulants on soil properties (biological, physical, or chemical) or soil functions. This knowledge gap should be addressed considering the vital role of soil processes in the bioavailability of nutrients, as reflected in crop productivity. This review evaluates laboratory and field experimental work on the effectiveness of common, non-microbial biostimulants, with a focus on their modes of action within the soil matrix. Of 2,097 initial articles returned through the search strings, 10 were within the scope of this review. A common soil biostimulant mechanism emerges from this literature. This relates to the supply of nutrients provided by the biostimulants, which stimulate native soil microbiology in mineralizing organic material in the soil, thus producing more bioavailable nutrients for plant uptake. Additionally, some articles link biostimulant effects to soil physical and chemical changes, which in turn impact soil biology (and vice versa). However, there is inconsistent evidence to provide full support for these explanatory mechanisms. This review highlights the need for further research into the effect of biostimulants on the native soil microbiology and associated soil properties, to provide greater clarity on biostimulants’ modes of action and greater mechanistic insights into how they can be used to improve crop production.

The azonal organo-accumulative soils (Umbrisols) on shungite rocks and the effect of land use on their properties and ecosystem carbon stock have been studied. The changes in soil profile morphology, main agrochemical and microbiological characteristics of the upper horizons, Corg and Cmic stocks in the 100-cm soil layer, and the structure of carbon pools are analyzed. Pine forest (control), arable land, hayfield, young alder stand, and middle-aged mixed forest are examined. In contrast to zonal soils, a change in land use does not considerably transform the properties of shungite soils. The removal of stones has the greatest effect, leading to the formation of developed arable horizons. The soils are characterized by highly skeletal shallow weakly differentiated profile, low bulk density, and pH close to neutral. A wide range of the Corg content (1.6 to 11.7%) results from a heterogeneous composition of the parent rock. Agricultural development contributes to the accumulation of exchangeable bases and available potassium and phosphorus, the contents of which are initially elevated in shungite soils. Characteristic of all examined sites is a high rate of organic matter mineralization (C/N ratio ≤17). A low Cmic content (84–245 mg C/kg) is recorded in the soils, which is explainable with a low availability of the substrate determined by a lithogenic nature of carbon and increased concentrations of heavy metals and lanthanides in shungite rocks. Soil Corg stock varies in the range of 17–251 t C/ha and Cmic stock, of 6–43 g C/m2. The total ecosystem carbon stock is the highest in hayfield (259 t C/ha) and lowest in young forest (74 t C/ha). The total carbon stock in the arable sites, middle-aged forest stand, and control forest is within 169–211 t C/ha. [ABSTRACT FROM AUTHOR]

Habitat for biodiversity is a crucial soil function. When assessed at large spatial scales, subjective assessment models are usually constructed by integrating expert knowledge to estimate soil biodiversity potentials (SBP) and predict their trends. However, these regional evaluation methods are challenging to apply mechanistically to other regions, especially in China, where soil biodiversity surveys are still in their infancy. Taking China (9.6 × 106 km2) as the study area, we constructed a Decision EXpert (DEX) multi-attribute decision model based on abiotic factors from soil and climate data that are known to be relevant for the habitat of soil biota. It was used to indirectly assess and map national SBP based on the habitat suitability for fungi, bacteria, nematodes, and earthworms in the topsoil. The results show: (1) the SBP in China was classified into five grades: low, covering 19.8% of the area, medium-low (21.2%), medium (16.0%), medium-high (38.5%), and high (4.5%); (2) the national SBP is at a moderate level, with hotspot areas (1.3 × 106 km2) located in the Yangtze Plain Region, the southeastern Southwest China Region, and the central-eastern South China Region; while the coldspot areas (2.6 × 106 km2) are located in the Gansu–Xinjiang Region and the northeastern Qinghai–Tibet Region; (3) Soil (pH, SOC, CEC, texture, total P, and C/N ratio) and climate (arid/humid regions, temperature zones) were identified as driving this SBP variation. This study presents a general approach to describing soil habitat function on a broad scale based on environmental covariates. It provides a systematic basis for selecting indicators and maps them to SBP from an objective perspective. This approach can be applied to regions where no soil organism survey is available and can also serve as a pre-survey for planning soil resource utilization and conservation. [ABSTRACT FROM AUTHOR]

Many ecological functions in cities are based on urban soils. In order to meet the needs of the expanding human population and the ensuing strain on natural resources, it is essential for soil-based ecosystems to function. Approximately 80% of the total urban land use in Akure and Okitipupa, Nigeria, are used for commercial, residential, and agricultural purposes. Thus, we investigated the potential of these three urban land use types (ULUTs) to offer a variety of ecosystem services in the two different cities. Soil properties that serve as proxy indicators for four ecosystem services were measured in the ULUTs: hydraulic conductivity (Kunsat) and available soil water for rainwater retention; soil organic carbon (SOC) stock for carbon storage; soil microbial respiration (SMR) for the capacity to support biological activity; and soil compaction (PR) and total nitrogen (TN) for promoting plant growth. The location and ULUT resulted in distinct ecosystem service provisioning. In comparison to Akure, Okitipupa soils had lower PR (1.0 vs 1.1 MPa) but higher Kunsat (36.9 vs 10.3 cm h−1), SOC stock (6.9 vs 5.7 Mg C ha−1), and SMR levels (35.2 vs 23.6 mg CO2-C g−1 soil). Commercial soils exhibited more compaction than residential and agricultural soils but less SOC stock and Kunsat, and TN in both locations. The properties of the urban soils showed that the soils could support a variety of ecosystem services. Different soil properties at the city level led to variations in the potential for ecosystem services in various locations, and these variations were observable in commercial, residential, and agricultural soils. Understanding urban soils would thus necessitate both cross-city comparative studies as well as within-city examinations of the potential for ecosystem services for various urban land use types. [ABSTRACT FROM AUTHOR]

Amorphous iron- and aluminium-(hydr)oxides are key soil properties in controlling the dynamics of phosphorus availability and carbon storage. These oxides affect the potential of soils to retain phosphorus and carbon, thus affecting ecosystem services such as crop production, water quality and carbon sequestration. In this study, we spatially predicted oxalate-extractable Fe and Al (FeOX, AlOX) contents in the Netherlands at 25 m resolution across six soil depth layers between 0 and 200 cm and quantified the associated prediction uncertainty using quantile regression forest. For model training and validation, geo-referenced data of FeOX and AlOX contents were used including 12,110 wet-chemical observations and 102,393 NIR spectroscopy observations. Over 150 spatial covariates were selected that provide information about soil typology, climate, soil organisms, land use, relief, parent material and space (sampling depth and oblique coordinates). Map quality was assessed by comparing predictions with observations using an independent data set of 4841 soil samples from agricultural fields. Soil sample locations were selected by stratified random sampling, allowing us to assess map quality using design-based statistical inference. Map quality was evaluated using the metrics Model Efficiency Coefficient (MEC), Root Mean Square Error (RMSE) and Mean Error (ME). Map quality differed, depending on the target variable and soil depth, with MEC ranging from 0.19 to 0.80, RMSE from 13.5 to 56.9 mmol kg−1 and ME from −6.8 to 6.8 mmol kg−1. Overall, map quality was better for topsoil than for subsoil and better for AlOX contents than for FeOX contents. Prediction uncertainty quality was evaluated by calculating the Prediction Interval Coverage Probability of the 90 per cent Prediction Interval, which were close to 0.90 in all cases and slightly below 0.90 for AlOX. Thus, prediction uncertainties were generally reliable, though for AlOX contents uncertainty was slightly underpredicted. The maps are a valuable tool for site-specific manure and fertiliser management strategies aiming to balance crop production, water quality and carbon sequestration in agriculture.

This review article aims to acknowledge the multifaceted functions of soil, and given its status as the largest terrestrial carbon store, to reaffirm its previously established importance in carbon sequestration. The article outlines the key variables that affect soil's ability to trap carbon and highlights the significance of soil in halting climate change. A bibliometric study of seven sets of keywords relating to the significance of soil in carbon sequestration for climate change mitigation laid the foundation for this review. The literature review that followed, which was based on the bibliometric analysis, concentrated on carbon sequestration and the impact of the key factors that affect the amount of organic carbon in soil, including (1) climatic conditions; (2) topography; (3) parent material; (4) organisms; and (5) soil qualities. The goal of this review article is to recognize the diverse roles of soil, while reasserting its well-documented significance in carbon sequestration. This is particularly important considering soil's position as the largest terrestrial storehouse of carbon. [ABSTRACT FROM AUTHOR]

An evaluation of soil quality sustainability can support decision making for the sustainable use of land resources. However, certain current problems associated with these evaluations remain unaddressed, e.g., the evaluation indicators do not fully reflect soil quality risks and the evaluation scale is not sufficiently small. In this study, 25,000 spatial grids of dimensions 3 km × 3 km are used to divide the major grain-producing regions in China, namely, the Sanjiang Plain and the Songnen Plain of Heilongjiang. Then, the soil erosion modulus, nutrient balance index, soil organic carbon (SOC) storage, heavy metal soil pollution index and crop productivity are calculated for each grid using the RULSE model, nutrient balance index model, soil type method, geoaccumulation index method and mechanism method, respectively. A spatial grid cluster analysis method is used to thoroughly evaluate and analyze the sustainability of soil quality in each grid. The results show that the overall soil status of the study area is good. The soil and water conservation levels are high, the soils show low levels of contamination, the crop production potential is high and the ratio of highly sustainable to moderately sustainable soils is approximately 2:1. Only 2.74% of the land is rated extremely unsustainable and needs to be restored to a basic level of productivity before subsequent functional restoration can be carried out. This study provides a new method for the fine-scale evaluation of soil quality and contributes to the management of land resources. [ABSTRACT FROM AUTHOR]

Forest restoration is considered among the most affordable and effective practices to address ecosystem and biodiversity loss and mitigate the impacts of human‐induced global change. Soils are intrinsically complex systems that mediate and regulate multiple processes and functions vital for forest ecosystem restoration. Although monitoring soil attributes are critical for evaluating the success of forest restoration projects, research, and development of soil function indicators are still limited. Here, we have reviewed the most commonly reported soil indicators in forest restoration research and their recovery trajectory on a global scale. We also identified and discussed less frequently used indicators that have the potential for monitoring ecosystem recovery. We found that soil indicators have considerably increased in the literature. However, research is regionally concentrated, and a significant proportion of publications neither considered reference ecosystems (41%) nor provided basic information about soil types (<21%). The most reported indicator types were chemical (76%) (e.g., soil carbon, nitrogen, and pH). A significant proportion of the studies (46%) performed long‐term evaluations (>15 years) of indicators. The majority of the indicators tended to resemble the levels of the reference ecosystem in the long term, with a few exceptions (e.g., water content and bulk density). We identified several less used but more integrative indicators with great potential for monitoring forest ecosystem recovery (e.g., aggregate stability, oxidizable carbon, soil respiration, and enzyme activity). Our results emphasize the need to effectively develop standardized soil health indicators to monitor ecosystem recovery under different conditions and expand their use in underrepresented regions. [ABSTRACT FROM AUTHOR]

Soil is a precious and non‐renewable resource that is under increasing pressure and the development of indicators to monitor its state is pivotal. Soil organic carbon (SOC) is important for key physical, chemical and biological soil properties and thus a central indicator of soil quality and soil health. The content of SOC is driven by many abiotic factors, such as texture and climate, and is therefore strongly site‐specific, which complicates, for example, the search for appropriate threshold values to differentiate healthy from less healthy soils. The SOC:clay ratio has been introduced as a normalized SOC level metric to indicate soils' structural condition, with classes ranging from degraded (<1:13) to very good (>1:8). This study applied the ratio to 2958 topsoils (0–30 cm) in the German Agricultural Soil Inventory and showed that it is not a suitable SOC level metric since strongly biased, misleading and partly insensitive to SOC changes. The proportion of soils with SOC levels classified as degraded increased exponentially with clay content, indicating the indicator's overly strong clay dependence. Thus, 94% of all Chernozems, which are known to have elevated SOC contents and a favourable soil structure, were found to have either degraded (61%) or moderate (33%) normalized SOC levels. The ratio between actual and expected SOC (SOC:SOCexp) is proposed as an easy‐to‐use alternative where expected SOC is derived from a regression between SOC and clay content. This ratio allows a simple but unbiased estimate of the clay‐normalized SOC level. The quartiles of this ratio were used to derive threshold values to divide the dataset into the classes degraded, moderate, good and very good. These classes were clearly linked to bulk volume (inverse of bulk density) as an important structural parameter, which was not the case for classes based on the SOC:clay ratio. Therefore, SOC:SOCexp and its temporal dynamic are proposed for limited areas such as regions, states or pedoclimatic zones, for example, in a soil health monitoring context; further testing is, however, recommended. [ABSTRACT FROM AUTHOR]

Abstract Background Microbes typically live in communities where individuals can interact with each other in numerous ways. However, knowledge on the importance of these interactions is limited and derives mainly from studies using a limited number of species grown in coculture. Here, we manipulated soil microbial communities to assess the contribution of interactions between microorganisms for assembly of the soil microbiome. Results By combining experimental removal (taxa depletion in the community) and coalescence (mixing of manipulated and control communities) approaches, we demonstrated that interactions between microorganisms can play a key role in determining their fitness during soil recolonization. The coalescence approach not only revealed the importance of density-dependent interactions in microbial community assembly but also allowed to restore partly or fully community diversity and soil functions. Microbial community manipulation resulted in shifts in both inorganic nitrogen pools and soil pH, which were related to the proportion of ammonia-oxidizing bacteria. Conclusions Our work provides new insights into the understanding of the importance of microbial interactions in soil. Our top-down approach combining removal and coalescence manipulation also allowed linking community structure and ecosystem functions. Furthermore, these results highlight the potential of manipulating microbial communities for the restoration of soil ecosystems. Video Abstract

The aim of the study was to assess the impact of the specialization of agricultural production on selected parameters of soil health, i.e., soil organic carbon content (SOC), soil acidification, soil nutrient status, i.e., total nitrogen content (NT), available forms of phosphorus, potassium, and magnesium, and microelements content, as well as the content of selected potentially toxic metals (PTMs). For the study, 18 farms located in the Masovian Voivodeship in Central Poland were selected. They were grouped into six types, and each type was represented by three farms. The study included organic farms; farms specializing in: crop, vegetable, poultry, dairy cattle, and pigs production. A total of 144 soil samples were analyzed. The results showed that the specialization of agricultural production and fertilizer management had a significant impact on most of the tested soil health parameters, except SOC and NT content. Despite the high organic fertilizer doses introduced into soils in poultry (170 kg N per hectare as poultry manure) and pig farms (150 kg N per hectare as pig manure), there was no significant influence of these amendments on SOC content. This may indicate low organic carbon sequestration potential in some Polish agricultural soils. Organic farms had the lowest levels of plant nutrients in the tested soil samples, which may limit soil productivity. All the tested soils were strongly acidified, which could restrict both production and regulatory soil functions. Based on the synthetic index of soil fertility (SSFI), vegetable and poultry farms were characterized by very high fertility, while crop, dairy cattle, and pig farms fell into the medium fertility class. Organic farms were in the lowest fertility class. However, the study suggests that the SSFI may not be the best indicator for assessing soil fertility and health; therefore, further research is needed.

Although crop conversion from annual to perennial crops has been considered as one path towards climate-smart and resource-efficient agriculture, the effects of this conversion on soil multifunctionality and biomass yields remain unclear. The objective of the study is to enhance soil multifunctionality while exerting a marginal influence on farmer income. Here, we investigated the effects of annual winter wheat (Triticum aestivum L.) and two perennial crops (a grass (Lolium perenne L.), a legume (Medicago sativa L.), and their mixture) on soil multifunctionality and biomass yield on the Yellow River floodplain. Soil multifunctionality was assessed by the capacity of water regulation and the multifunctionality of carbon (C), nitrogen (N), and phosphorus (P) cycles. C cycle multifunctionality index is the average of β-xylosidase, β-cellobiosidase, and β-1, 4-glucosidase. N cycle multifunctionality index is the average of L-leucine aminopeptidase and β-1, 4-N-acetyl-glucosaminidase, and acid phosphatase represented (and dominated) P cycle functions. The results showed that perennial crops enhanced soil multifunctionality by 207% for L. perenne, 311% for M. sativa, and 438% for L. perenne + M. sativa, compared with annual winter wheat (T. aestivum). The effect of perennial crops on soil multifunctionality increased with infiltration rate, dissolved organic C, microbial biomass C, and extracellular enzymatic activities for both C and N acquisition. However, we observed that perennial crops had a lower biomass yield than annual crop. Therefore, the transition of agricultural landscapes to perennials needs to take into account the balance between environmental protection and food security, as well as environmental heterogeneity, to promote sustainable agricultural development.

The UN Sustainable Development Goals (SDGs) have a deadline of 2030 so, restricting attention to agriculture, development and implementation of management measures, aimed at reaching the goals, is urgent. Even though the current 159 very broad targets and 234 indicators for the SDGs don't mention soils, soils play a key role when addressing indicators 2.4.1 and 15.3.1 aimed at “sustainable agriculture” and “degraded land”, by introducing operational methods to assess soil health and interdisciplinary ecosystem services in line with the SDGs. Application of the soil security concept, combining biophysical and socioeconomic approaches, is essential for sustainability research where dominant socioeconomic considerations by stakeholders should frame the biophysical analysis. If stakeholders don't embrace SDG-inspired innovative management, nothing will materialize in the real world. Much research is still needed to address inter- and transdisciplinary sustainability issues but a plea is made at this critical point in time to also apply a relatively straightforward and pragmatic research approach, essentially based on available data and methods, to assess ecosystem services, defining indicators and thresholds, in line with five key SDGs. Reference is made to an exploratory Dutch case study in a:”Living Lab”. The National Soil Health Institute in the US has already pioneered such a pragmatic approach by first emphasizing socioeconomic aspects and by incorporating the soil health analysis in regenerative farm management that is recognized by farmers. But the five ecosystem services will still have to be assessed here to maintain the link with the SDGs and the policy arena. The 5C's of soil security apply very well at farm level. The soil science profession will benefit from showing specific examples of “Living Labs” where five thresholds of ecosystem services are met, creating: ”Lighthouses” showing examples of achieved sustainable development in which soil health plays a key role as demonstrated by specific measurements.

The response of the microbial community of soils to different levels of oil contamination was studied in a model experiment by the parameters: basal respiration (BR), substrate induced respiration (SIR), carbon of microbial biomass (Cmic), potential denitrification (DNF), methanogenesis, and catalase activity. We analyzed light-chestnut (Haplic Kastanozems Sodic) and meadow-chestnut (Gleyic Kastanozems Chromic) soils of the dry-steppe zone of Stavropol region, differing in the organic matter amount, salinity, and the content of physical clay. The intensity of BR increased within a 30-day-period after the crude-oil input to the soils and caused the growth of Cmic due to activation of oil-oxidizing microorganisms in anaerobic zones of soils. The variations in DNF in light-chestnut and meadow-chestnut soils were in different directions, which was probably related to the organic-matter content and salinity of the soils. The catalase activity was a sensitive indicator of petroleum hydrocarbons in light-chestnut soil, but salinity was the determining factor for its activity in meadow chestnut soil. Biotesting with the use of worms Eisenia fetida showed the inability of test organisms to survive in non-contaminated chestnut soils. The BR and SIR related to it were significant indicators, which did not depend on natural factors in chestnut soils. Catalase activity and DNF are limited by the salinity factor. [ABSTRACT FROM AUTHOR]

Soil biology encompasses a vast diversity of organisms contributing to soil processes and functions that underpin the delivery of soil ecosystem services. We review the response of soil biology to long-term phosphorus (P) and nitrogen (N) fertiliser application, focusing on trials conducted at Winchmore and Ballantrae Research Stations under sheep grazing. Application of P and N fertiliser increases soil fertility and pasture production and can have impacts on soil biology. Higher earthworm abundance was associated with increasing P, but not N fertiliser application. Microbial biomass or respiration tended to increase with P application but decrease with N application. Both P and N fertiliser decreased fungal biomass. The few microbial functional groups studied also appear responsive to fertilisation. A decline in soil pH may have driven some of these changes and could have been mitigated with lime. Other factors, such as plant composition, may also be important to the soil biology but have received limited attention in these studies. There are currently few indicators that can be used on-farm to assess soil biology. We discuss these as well as measures that can be used in a research context to inform the impacts of fertiliser use on soil biology and its functioning. [ABSTRACT FROM AUTHOR]

Over the last few years, in the literature on the incorporation of crop residues in agricultural fields to mitigate climate change, there has been a growing tendency to no longer distinguish between the storage and the sequestration of organic carbon in soils. Applying, apparently for the first time, a simple "back‐of‐the‐envelope" calculation to available mineralization kinetics data, we show graphically that there are fundamental differences, both quantitatively and qualitatively, between the two concepts of storage and sequestration. To avoid confusion, they should therefore never be used interchangeably, especially when addressing farmers and policymakers. Several simplifying assumptions made in the calculations, and about which a considerable lack of understanding persists, mean that at this stage, the graphical visualization we obtained is likely to still be optimistic in terms of the already low (10%) efficacy of sequestering carbon in soils. Several research avenues are outlined to deepen our grasp of the processes involved. [ABSTRACT FROM AUTHOR]

In summer 2018, Central Europe was hit by an extreme drought event that widely impacted ecosystems and markedly increased tree mortality in forest ecosystems across the continent. As climate models predict an increase in frequency and severity of such events, there is an urgent need to adapt forests in order to maintain the diverse benefits they provide. Soil processes play an essential role in this context and are key for a plethora of terrestrial ecosystem functions, but they are strongly dependent on water availability. Here, we investigated how tree species richness (TSR), composition, and identity in a 13‐year‐old temperate tree diversity experiment influenced selected ecosystem functions (as important representatives of different ecosystem processes) during the 2018 summer drought. We focused on the stability of soil microbial biomass and standard litter decomposition, as well as tree species‐specific mortality rates. Contrary to our expectations, TSR did not generally increase the resistance of soil functions or decrease tree mortality rates. However, the resistance of these functions was determined by tree species identity and community composition. For the resistance of both soil functions (microbial biomass and litter decomposition), we found that TSR effects depended on the presence of certain tree species. Moreover, we found that the performance of a specific tree species in monoculture, Norway spruce, was a poor predictor of its response to drought in tree species mixtures. Taken together, the results of our study demonstrate that the species composition of tree stands determines tree mortality and the resistance of soil functions under drought. This indicates that enhancing multiple ecosystem functions under environmental disturbance requires maintaining diverse forests. [ABSTRACT FROM AUTHOR]

Diagnostic horizons, properties and materials are commonly applied building units of national and international soil classification systems. The presence, depth or absence of diagnostic information supports the process of objective soil classification, such as the World Reference Base (WRB). While the diagnostic units and associated descriptive qualifiers convey information that reflect pedogenesis, they also indicate important, and often complex properties that are related to soil fertility and other soil functions. The spatial extent or the continuum of diagnostic information is often different from the spatial extent of the mapping units in general soil maps (mostly reflecting soil types). This paper presents the spatial distribution of selected diagnostic units and qualifiers for the European Union and describes their significance for key soil functions. The derivation of selected diagnostics was performed based on the information provided in the European Soil Database and by taking into consideration the definitions, rules and allocation procedure of soils to the appropriate Reference Soil Group (RSG) defined by the WRB key. The definition of the presence/absence of the diagnostic units were performed by extracting information related to the first level of the WRB classification and to the qualifiers provided by the ESDB on the Soil Taxonomic Units (STU) level. The areal percentage of the STUs (thus, the derived diagnostics) within Soil Mapping Units (SMUs) was calculated and was visualized on separate maps. The study demonstrated the importance of the spatial information that the diagnostic elements convey, especially related to soil functions.

Soil is often described as a ‘black box’, as surprisingly little is known about the high levels of biodiversity that reside there. For aboveground organisms, we have good knowledge of the distribution of the species and how they might change under future human impacts. Yet despite the fact that soil organisms provide a wide variety of ecosystem functions, we have very limited knowledge of their distribution and how their diversity might change in the future. In order to create accurate and generalisable models of biodiversity, the underlying data need to be representative of the entire globe. Yet even with our recently compiled global earthworm dataset of over 11000 sites, there are gaps across large regions. These gaps are consistent across many other datasets of both above- and belowground diversity. In order to fill the gaps we propose a sampling network (SoilFaUNa), to create a comprehensive database of soil macrofauna diversity and soil functions (e.g. decomposition rates). Building on the existing dataset of earthworm diversity and early data from the SoilFaUNa project, we will investigate changes in earthworm diversity. From our current work, we know that both climate and land use are main drivers in predicting earthworm diversity, but both will change under future scenarios and may alter ecosystem functions. We will, using space-for-time substitution models, estimate how earthworm diversity and their functions might change in the future, modelling earthworm diversity as a function of climate, land use and soil properties and predicting based on future scenarios. Previous studies of aboveground diversity changes over time using time-series analysis have found no-net-loss in richness, but analyses have criticisms. We aim to use time-series data on earthworms to move this debate forward, by using data and statistical methods that would address the criticisms, whilst increasing our knowledge on this understudied soil group. Field experiments and micro-/mesocosm experiments have been used to investigate the link between a number of soil organisms and ecosystem functions under few environmental conditions. Meta-analyses, which can produce generalisable results can only answer questions for which there are data. Thus, we have been lacking on information on the link between the entire community of soil fauna and ecosystem functions and impact of changes to the soil fauna community across environmental contexts. Using data collected from the SoilFaUNa project, we will, for the first time, synthesise globally distributed specifically-sampled data to model how changes in the community composition of soil macrofauna (due to changes in land use, climate or soil properties) impact the ecosystem functions in the soil.

Background: Microbes typically live in communities where individuals can interact with each other in numerous ways. However, knowledge on the importance of these interactions is limited and derives mainly from studies using a limited number of species grown in coculture. Here, we manipulated soil microbial communities to assess the contribution of interactions between microorganisms for assembly of the soil microbiome. Results: By combining experimental removal (taxa depletion in the community) and coalescence (mixing of manipulated and control communities) approaches, we demonstrated that interactions between microorganisms can play a key role in determining their fitness during soil recolonization. The coalescence approach not only revealed the importance of density-dependent interactions in microbial community assembly but also allowed to restore partly or fully community diversity and soil functions. Microbial community manipulation resulted in shifts in both inorganic nitrogen pools and soil pH, which were related to the proportion of ammonia-oxidizing bacteria. Conclusions: Our work provides new insights into the understanding of the importance of microbial interactions in soil. Our top-down approach combining removal and coalescence manipulation also allowed linking community structure and ecosystem functions. Furthermore, these results highlight the potential of manipulating microbial communities for the restoration of soil ecosystems. 1hnKtMhPkxX_a_nwXw9y6K Video Abstract [ABSTRACT FROM AUTHOR]

Healthy soils provide the foundation for sustainable agriculture. However, soil health degradation has been a significant challenge for agricultural sustainability and environmental quality in water-limited environments, such as arid and semi-arid regions. Soils in these regions is often characterized by low soil organic matter (SOM), poor fertility, and low overall productivity, thus limiting the ability to build SOM. Soil health assessment frameworks developed for more productive, humid, temperate environments typically emphasize building SOM as a key to soil health and have identified the best management practices that are often difficult to implement in regions with water limitations. This study reviewed existing soil health assessment frameworks to assess their potential relevance for water-limited environments and highlights the need to develop a framework that links soil health with key ecosystem functions in dry climates. It also discusses management strategies for improving soil health, including tillage and residue management, organic amendments, and cropping system diversification and intensification. The assessment of indicators sensitive to water management practices could provide valuable information in designing soil health assessment frameworks for arid and semi-arid regions. The responses of soil health indicators are generally greater when multiple complementary soil health management practices are integrated, leading to the resilience and sustainability of agriculture in water-limited environments. [ABSTRACT FROM AUTHOR]

Contamination of soils in agroecosystems with microplastics (MPs) is of increasing concern. The contamination of the environment/farmland soils with MPs (1 µm to 5 mm sized particles) and nanoplastics (NPs; <1 µm sized particles) is causing numerous effects on ecological soil functions and human health. MPs enter the soil via several sources, either from intentional plastic use (e.g., plastic mulch, plastic greenhouses, plastic‐coated products) or indirectly from the input of sewage sludge, compost, or irrigation water that is contaminated with plastic. Once in the soil, plastic debris can have various impacts such as changes in soil functions and physicochemical properties and it affects soil organisms due to its toxic behavior. This review paper describes the different effects of plastic waste to understand the consequences for agricultural productivity. Furthermore, we identify knowledge gaps and highlight the required approaches, indicating future research directions on sources, transport, and fate of MPs in soils to improve our understanding of various unspecified abiotic and biotic impacts of MP pollution in agroecosystems. [ABSTRACT FROM AUTHOR]

Soil degradation threatens agricultural production and soil multifunctionality. Efforts for private and public governance are increasingly emerging to leverage sustainable soil management. They require consensus across science, policy, and practice about what sustainable soil management entails. Such agreement does not yet exist to a sufficient extent in agronomic terms; what is lacking is a concise list of soil management measures that enjoy broad support among all stakeholders, and evidence on the question what hampers their implementation by farmers. We therefore screened stakeholder documents from public governance institutions, nongovernmental organizations, the agricultural industry, and conventional and organic farmer associations for recommendations related to agricultural soil management in Germany. Out of 46 recommended measures in total, we compiled a shortlist of the seven most consensual ones: (1) structural landscape elements, (2) organic fertilization, (3) diversified crop rotation, (4) permanent soil cover, (5) conservation tillage, (6) reduced soil loads, and (7) optimized timing of wheeling. Together, these measures support all agricultural soil functions, and address all major soil threats except soil contamination. Implementation barriers were identified with the aid of an online survey among farmers (n = 78). Results showed that a vast majority of farmers (> 80%) approved of all measures. Barriers were mostly considered to be economic and in some cases technological, while missing knowledge or other factors were less relevant. Barriers were stronger for those measures that cannot be implemented in isolation, but require a systemic diversification of the production system. This is especially the case for measures that are simultaneously beneficial to many soil functions (measures 2, 3, and 4). Results confirm the need for a diversification of the agricultural system in order to meet challenges of food security and climate change. The shortlist presents the first integrative compilation of sustainable soil management measures supporting the design of effective public or private governance. [ABSTRACT FROM AUTHOR]

Soil provides essential ecosystem services sustaining and improving human life, but mapping soil functions is an ongoing challenge. Denmark has a long history of carrying out soil assessments - originally in order to determine tax revenues for the king, and, more recently, for aiding policymakers and farmers. This knowledge has supported the development of intensive agricultural systems while maintaining the provision of ecosystem services (e.g., clean water). Getting an overview of historical soil surveys and pedological mapping approaches can generate useful information for mapping soil, identifying gaps and proposing directions for future research. In this review, we explore the evolution of soil and environmental inventories, the historical development of soil mapping methods, and how these factors contributed to a better spatial understanding of soil functions. Specifically, we discuss soil functions related to water regulation (e.g., drainage, groundwater and water surface interactions, water table), water filtering (e.g., nitrogen leaching), carbon sequestration (e.g., peatlands), agricultural production (e.g., land suitability, wheat yields), and threats related to soil degradation (e.g., soil erosion). Denmark has benefitted from a government-coordinated approach, promoting detailed and systematic national soil surveys and environmental monitoring programmes. The large databases produced in the surveys formed the basis for mapping several soil properties and functions at increasingly high resolutions over the last many years based on developments in machine learning. In contrast to methodological advances in soil mapping and relevant contributions to pedometric research, we identified a lack of spatial information on soil biodiversity. Detailed spatial information about soil functions is essential to address global issues, such as climate change, food security and water security, and the experience of mapping soil functions in Denmark can be a source of inspiration to other parts of the world. [ABSTRACT FROM AUTHOR]

Grazing is the main way of utilizing understory vegetation in the tropics. However, the effects of grazing on vegetation diversity and soil functions in coconut plantations remain unclear. Therefore, this study was conducted in a young coconut plantation that was grazed by geese in Wenchang, China. We identified four grazing intensities according to the aboveground biomass, namely, no grazing (CK), light grazing (LG), moderate grazing (MG), and heavy grazing (HG). In April 2022, we used the quadrat method to investigate the composition and traits of vegetation, collected and analyzed 0-40-cm soil samples in each grazing intensity. The results showed that grazing changed the composition of understory species. The predominant species changed from Bidens pilosa to Praxelis clematidea + Paspalum thunbergii and then to P. clematidea with increasing grazing intensity. The richness, Shannon-Wiener index, evenness, modified functional attribute diversity (MFAD), functional divergence (Fdiv), and functional evenness (Feve) of CK were 4.5, 1.0, 0.29, 0.20, 0.84, and 0.80, respectively. Taxonomic diversity did not respond to LG, but responded significantly to MG and HG. Compared with CK, MG and HG increased richness by 96% and 200%, respectively, and Shannon-Wiener index increased by 40% and 98%, respectively. HG increased evenness by 95%. For functional diversity, MG and HG increased MFAD by 164% and 560%, respectively, but Fdiv and Feve did not respond to grazing intensity. The carbon (C) functioning, nitrogen (N) functioning, phosphorus (P) functioning, and multifunctionality in the 0-10-cm topsoil of CK were -0.03, 0.37, -0.06, 0.20, and 0.14, respectively. Grazing increased C functioning, P functioning, and multifunctionality in the 0-10-cm topsoil but decreased N functioning. Multiple linear regression showed that the taxonomic diversity and functional diversity could be used to estimate soil functions, but these vary among soil layers. In general, MG and HG can increase vegetation diversity and soil function. It may be possible to promote even distribution of geese by adding water sources or zoning grazing. Furthermore, quantitative grazing experiments are needed to determine the efficient use pattern of the understory in coconut plantations in tropics. [ABSTRACT FROM AUTHOR]