•No-till and reduced tillage systems improved the quality of surface soil.•Strategic tillage improved soil functions and overall quality compared to no till.•High organic matter content did not ...significantly improve water relation function.•Productivity function in reduced tillage is higher than conventional and no tillage.
Agricultural practices should be carefully monitored for long-term impacts on soil quality to avoid further deterioration in ecosystem services provided by soils. The aim of this study was to evaluate and compare the effects of two conventional (CT), three reduced (RT) and two no-till (NT) tillage practices on soil quality of a clayey soil in a ten-year experiment using Soil Management Assessment Framework (SMAF). The field experiment was established in 2006 with six tillage methods, and winter wheat (Triticum aestivum L.), soybean (Glycine max. L.) – grain corn (Zea mays L.) crop rotation. The NT plots were divided into two parts, i.e., half of them were plowed with a moldboard plow during November 2015, and this practice was defined as strategic tillage (ST), while the remaining half was left undisturbed (NT). Disturbed and undisturbed soil samples were collected at three depths (0−10, 10−20 and 20−30 cm) from experimental plots in 2016. Fourteen soil quality indicators, including physical, chemical and biochemical properties were determined to assess soil quality. Soil productivity, water relations (WR), resistance and resilience (RR), and physical stability and support (PSS) functions defined in SMAF were calculated. The RR and PSS function scores were significantly higher at 0−10 cm depth under conservational tillage methods (RT and NT) compared to CT methods. Low nutrient content, compaction, aggregate size and stability values in 10−30 cm depth decreased the functioning potential. The RR function at 0−10 cm depth in NT method was 103 % and 72 % higher than CT-1 and CT-2, respectively. All soil functions under RT and NT methods decreased with depth. The ST significantly increased PSS and WR functions in all sampling depths and overall soil quality in 10−20 and 20−30 cm depths compared to long-term NT method. The comparison of soil functions and overall soil quality indices helped to identify the effects of different tillage practices on functional potential of the soil. Furthermore, soil quality assessment using soil functions provides an overview to distinguish the pros and cons of tillage practices on sustainability of the crop production.
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•Introducing a digital soil mapping method that uses a physically based model.•Water movement functions as a proxy for pedogenesis through covariate relationships.•Hydrologic models ...captured temporal trends of water tables and soil moisture.•Spatial-temporal patterns of water movement were related with fragic properties.•Hydrologic models add a time and depth component to bidimensional soil maps.
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.
Primary or secondary forests around the world are increasingly being converted into plantations. Soil microorganisms are critical for all biogeochemical processes in ecosystems, but the effects of ...forest conversion on microbial communities and their functioning remain unclear. Here, we conducted a meta‐analysis to quantify the impacts that converting forests to plantations has on soil microbial communities and functioning as well as on the associated plant and soil properties. We collected 524 paired observations from 138 studies globally. We found that conversion leads to broad range of adverse impacts on soils and microorganisms, including on soil organic carbon (−24%), total nitrogen (−29%), bacterial and fungal biomass (−36% and −42%, respectively), microbial biomass carbon (MBC, −31%) and nitrogen (−33%), and fungi to bacteria ratio (F:B, −16%). In addition, we found impacts on the ratio of MBC to soil organic C (qMBC, −20%), microbial respiration (−18%), N mineralization (−18%), and enzyme activities including β‐1,4‐glucosidase (−54%), β‐1,4‐N‐acetylglucosaminidase (−39%), and acid phosphatase (ACP; −34%). In contrast, conversion to plantations increases bacterial richness (+21%) and microbial metabolic quotient (qCO2, +21%). The effects of forest conversion were consistent across stand ages, stand types, and climate zone. Soil C and N contents as well as the C:N ratio were the main factors responsible for the changes of microbial C, F:B, and bacterial richness. The responses of qCO2, N mineralization, and ACP activity were mainly driven by the reductions in F:B, MBC, and soil C:N. Applying macro‐ecology theory on ecosystem disturbance in soil microbial ecology, we show that microbial groups shifted from K to r strategists after conversion to plantations. Our meta‐analysis underlines the adverse effects of natural forests conversion to plantations on soil microbial communities and functioning, and suggests that the preservation of soil functions should be a consideration in forest management practices.
Conversion of primary or secondary forests to plantations is constantly increasing worldwide. This study conducted a meta‐analysis to quantify the impacts that converting forests to plantations has on soil and microbial properties and functions. We found that forest conversion significantly decreased soil organic C and N contents, microbial biomass, fungi to bacteria ratio, microbial respiration, and N mineralization, but increased bacterial richness and microbial metabolic quotient. Microbial groups were found shifted from K‐strategist dominated to r‐strategist dominated after conversion to plantations. We therefore suggest that the preservation of soil functions should be a consideration in forest management practices.
•We develop a conceptual framework on Functional Land Management to inform and support policies on sustainable intensification in agriculture.•Conceptual diagrams are used to illustrate the ...individual supply of five key soil ecosystem services (soil functions) in the agronomic sector.•A functional soil matrix shows the variation in the multi-functional capacity of the soil under different types of land use and soil drainage.•A case study is provided to demonstrate the application of multi-functional land use planning at national level.
Agricultural soils offer multiple soil functions, which contribute to a range of ecosystem services, and the demand for the primary production function is expected to increase with a growing world population. Other key functions on agricultural land have been identified as water purification, carbon sequestration, habitat biodiversity and nutrient cycling, which all need to be considered for sustainable intensification. All soils perform all functions simultaneously, but the variation in the capacity of soils to supply these functions is reviewed in terms of defined land use types (arable, bio-energy, broadleaf forest, coniferous forest, managed grassland, other grassland and Natura 2000) and extended to include the influence of soil drainage characteristics (well, moderately/imperfect, poor and peat). This latter consideration is particularly important in the European Atlantic pedo-climatic zone; the spatial scale of this review. This review develops a conceptual framework on the multi-functional capacity of soils, termed Functional Land Management, to facilitate the effective design and assessment of agri-environmental policies. A final functional soil matrix is presented as an approach to show the consequential changes to the capacity of the five soil functions associated with land use change on soils with contrasting drainage characteristics. Where policy prioritises the enhancement of particular functions, the matrix indicates the potential trade-offs for individual functions or the overall impact on the multi-functional capacity of soil. The conceptual framework is also applied by land use area in a case study, using the Republic of Ireland as an example, to show how the principle of multi-functional land use planning can be readily implemented.
Biochar applications can have important implications for many of the soil functions upon which agroecosystems rely, particularly regarding organic carbon storage. This study evaluated the impacts of ...adding a highly aromatic gasification biochar at different rates (0, 12 and 50 t ha-1) to a barley crop on the provision of crucial soil functions (carbon sequestration, water content, greenhouse gas emissions, nutrient cycling, soil food web functioning, and food production). After natural ageing in the field for six years, a wide range of soil properties representative of the studied soil functions were measured and integrated into a soil quality index. Results showed that C sequestration increased with biochar rate (23 and 68% higher than in the control for the 12 and 50 t biochar ha-1 treatments, respectively). Water content was enhanced at the 50 t ha-1 treatment depending on the sampling date. Despite biochar additions neither abating nor increasing CO2 equivalent emissions (carbon dioxide plus nitrous oxide and methane), the system shifted from being a methane sink (-0.017 ± 0.01 mg CH4-C m-2 h-1 at the 12 t ha-1 treatment), to a net source (0.025 ± 0.02 mg CH4-C m-2 h-1 at the 50 t ha-1 treatment). In addition, biochar ageing provoked a loss of nitrate mitigation potential, and indeed ammonium production was stimulated at the 50 t ha-1 rate. The 50 t ha-1 treatment also adversely affected nematode and collembolan functional diversity. Lastly, biochar did not affect barley yield. The results of the soil quality index indicated that no biochar treatment provided more benefits to our agricultural soil, and, although the 50 t ha-1 treatment increased C sequestration, this was potentially offset by its harmful effects on soil faunal communities. Therefore, application of this biochar at high rates should be avoided to prevent risks to soil biological communities.
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•Biochar effects on multiple soil functions were assessed using a soil quality index.•Biochar amendment (12 and 50 t ha-1) did not increase soil quality versus the control.•The 50 t ha-1 rate sequestered more C but impaired soil food web functioning.
ABSTRACT Brazilian soil scientists have increased the use of the term “soil quality” in their scientific publications in the last decade. However, it remains unclear if those publications only ...mention “soil quality” in a broad context, or the studies are focused on soil quality assessments, integrating soil chemical, physical and biological indicators. The objective of this systematic review was to carry out a critical analysis of the conception in using the term “soil quality” in recent publications derived from studies performed in Brazil. For this purpose, the terms (“soil health” or “soil quality” or “qualidade do solo”) and (“Brazil*” or “Brasil*”) were searched in databases of Web of Science, Scopus, and Scielo from 2014 to 2021. Initially, 1,284 peer-reviewed papers were found, subsequently selected according to the criteria established in two filters: (i) First filter - studies carried out in Brazil, which mentioned at least one of the terms of interest (“soil health” or “soil quality” or “qualidade do solo”) and that evaluated soil biological, physical or chemical indicators, assessing at least one of them; (ii) Second filter - studies in which all three groups of soil indicators were assessed and integrated, and presented a specific discussion about soil quality. According to the results, 36 % of the papers met the first criteria (n = 464), and only 2 % (n = 30) attended the second filter. The terms “soil health” or “soil quality” or “qualidade do solo” were mentioned 7 and 37 times per paper for those papers selected in the first and second filter, respectively. We evidenced in our study that the term soil quality in agricultural science papers has been predominantly used in a broad context, mostly to refer to the suitable soil conditions for plant growth. Thus, we concluded that even if the use of soil quality term is increasing in Brazilian literature, there are still very few researchers working specifically with soil quality assessments, in its full conception (i.e., integrating chemical, physical and biological indicators). Therefore, there is a promising research field to be explored to promote scientific advances in the soil quality area (e.g., new concepts, assessment frameworks, on-farm monitoring protocols), as well as disseminate the soil quality assessment among the Brazilian farmers, environmentalists, and other stakeholders.
•The long-term effects of different managements on soil functions were investigated.•Natural grass cover determined a better water movement and retention.•Carbon stock was negatively affected by ...tillage only in the inter-row.•Collembola and eu-edaphic forms were more sensitive to soil perturbation.•Conservation tillage was not effective in maintaining soil functionality.
The long-term effects of two different soil management practices, natural grass cover (NC) and conservation tillage (CT), on soil functions (carbon sequestration, habitat for organisms, and water movement and retention) were determined in a high-density, mature olive orchard (Olea europaea L. cv. Frantoio) growing in a sandy loam soil (Typic Haploxeralf) in a Mediterranean environment. Ten years after the beginning of the different soil management, soil samples were collected at 0–10 and 10–20 cm depth and at two distances from the trunk, underneath the olive canopy (UC) and in the inter-row (IR). There were no differences in fruit yield, oil yield, and yield efficiency between the two soil management systems during the 2011–2013 period. CT negatively affected soil organic carbon pools (total and humified), but only at the IR position. The distance from the plant did not significantly influence soil structure and hydrological properties, while NC treatment increased water movement and retention. Tillage reduced the microarthropod abundance, in particular Collembola and eu-edaphic forms, which were the most sensitive groups to soil perturbation. We conclude that natural grass cover was more effective than conservation tillage in maintaining or improving elements of soil functionality.
•Stuying DSM products for spatializing the STICS model (simulated yield and drainage)•Comparisons of STICS outputs using observed vs DSM estimated STICS soil parameters.•DSM products outperformed the ...soil map for providing the STICS soil parameters.•Few yearly and the all-year-aggregated simulations were impacted by DSM errors.•Coupling DSM with a crop model: an interesting solution for Digital Soil Assessment.
Digital Soil Mapping (DSM) can be an alternative data source for spatializing crop models over large areas. The objective of the paper was to evaluate the impact of DSM products and their uncertainties on a crop model’s outputs in an 80 km2 catchment in south India. We used a crop model called STICS and evaluated two essential soil functions: the biomass production (through simulated yield) and water regulation (via calculated drainage). The simulation was conducted at 217 sites using soil parameters obtained from a DSM approach using either Random Forest or Random Forest Kriging. We first analysed the individual STICS simulations, i.e., at two cropping seasons for 14 individual years, and then pooled the simulations across years, per site and crop season. The results show that i) DSM products outperformed a classical soil map in providing spatial estimates of STICS soil parameters, ii) although each soil parameters were estimated separately, the correlations between soil parameters were globally preserved, ii) Errors on STICS’ yearly outputs induced by DSM estimations of soil parameters were globally low but were important for the few years with high impacts of soil variations, iii) The statistics of the STICS simulations across years were also affected by DSM errors with the same order of magnitude as the errors on soil inputs and iv) The impact of DSM errors was variable across the studied soil parameters. These results demonstrated that coupling DSM with a crop model could be a better alternative to the classical Digital Soil Assessment techniques. As such, it will deserve more work in the future.
Soil desertification has a significant social, economic, and environmental impact worldwide. Mycorrhizal diversity remains poorly understood in semiarid regions impacted by desertification, ...especially in Brazilian drylands. More importantly, positive impacts of grazing exclusion on mycorrhizal communities are still incipient. Here, we hypothesized that overgrazing changes the structure of Arbuscular Mycorrhizal Fungi (AMF) community compared to native areas and, grazing exclusion is effective to restore the AMF community. Thus, we analyzed the status of AMF community in soils under desertification (overgrazing) and restoration (twenty-years of grazing exclusion) in the Brazilian semiarid. AMF-spores were extracted via humid decantation methodology, morphologically classified, and alpha diversity metrics were calculated. Soil samples were chemically, and physically characterized and multivariate statistical analyses were applied to verify the impact of soil degradation and restoration on AMF-community. Briefly, native, and restored areas presented higher contents of organic matter, phosphorus, microbial carbon, and β-glucosidase activity. However, degraded soil showed higher Al3+, Na+, and bulk soil density values. The abundance of AMF spores was higher in restored soil, followed by degraded and native vegetation, and Shannon’s diversity index was significantly higher in restored soils, followed by native vegetation. AMF-spores were classified into four families (Gigasporaceae > Acaulosporaceae > Glomeraceae > Ambisporaceae). Ambisporaceae was closed correlated with degraded soil, mainly with Al3+, Na+, and bulk soil density properties. On the other hand, Acaulosporaceae and Glomeraceae were positively correlated with native vegetation and restored soil, respectively, thereby improving Shannon index, richness, enzyme activity, and soil respiration. Thus, grazing exclusion, in long term, can be a good strategy to restore AMF-diversity in soils in the Brazilian semiarid.
•Soil desertification negatively impacted AMF community in Brazilian semiarid soil.•Grazing-exclusion improved the status of AMF community.•AMF diversity was higher in native and restored areas of Brazilian semiarid.•Grazing exclusion increases soil fertility (chemical and biological), while desertification decreased it.
•Traction and repeated wheeling effects were independently assessed in field trial.•Soil structural deformation of a sandy loam topsoil was quantified.•High traction substantially increased soil ...compaction.•Soil structural deformation increased with the number of wheel passes.•A single pass with traction was more harmful than multiple passive wheeling.
Soil compaction caused by the use of heavy agriculture machinery in non-optimal soil conditions hampers crucial soil functions. Tyre inflation pressure and wheel load are well-known key drivers of compaction. The effects of traction and repeated wheeling are, however, not yet fully understood but may be of critical importance. We aimed to quantify the effects of traction and repeated wheeling on some soil structural properties independently in a compaction experiment conducted on a sandy loam at a soil water content near field capacity, using a tractor-trailer combination at two loads. The trailer was used in ‘standard’ and ‘offset’ steering modes, the latter referring to the mode in which measurements could be taken for the pass of a single towed and thereby passive trailer wheel (with one, two, three and six wheel passes). Penetration resistance was measured to 0.71 m depth and 100-cm3 soil cores were collected around 0.16 m depth for structural property measurements. In the offset steering mode, the measurements were made in the tractor tracks to investigate the effect of traction and in the trailer’s wheel track to investigate the effect of repeated wheeling (at 6.0 Mg static wheel load). The measurements were also collected for the standard steering configuration with the high towed load and from reference plots. Measurements on the soil cores comprised bulk density, porosity, and air permeability. We found a clear effect of traction on deformation of some soil structural properties, with no significant effects of the low drawbar pull but with substantial effects of the high drawbar pull. Reductions in air permeability and specific permeability were significant (89 % and 83 %, respectively) and indicated a densification and homogenisation of the soil. The effect of repeated wheeling was gradual and reasonably well explained by a linear fit to the number of wheel passes. After six passes with the passive wheel caused some soil structural properties to differ significantly from the reference soil, and resulted in approximately similar levels of bulk density, porosity, air permeability and specific permeability as the tractor with high drawbar pull. Still, the deformation was stronger for the single pass of the tractor with the high drawbar pull than for six repeated wheeling of the passive trailer wheel. These results highlight the substantial effect of traction on soil compaction. Yet, the mechanisms causing this deformation remain speculative until the propagation of horizontal stress through the soil profile is better understood.
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