Modelling of long-term Zn, Cu, Cd and Pb dynamics from soils fertilised with organic amendments

Soil contamination by trace elements (TEs) is a major concern for sustainable land management. A potential source of excessive inputs of TEs into agricultural soils are organic amendments. Here, we used dynamic simulations carried out with the Intermediate Dynamic Model for Metals (IDMM) to describe the observed trends of topsoil Zn (zinc), Cu (copper), Pb (lead) and Cd (cadmium) concentrations in a long-term (>60-year) crop trial in Switzerland, where soil plots have been treated with different organic amendments (farmyard manure, sewage sludge and compost). The observed ethylenediaminetetraacetic acid disodium salt (EDTA)-extractable concentrations ranged between 2.6 and 27.1 mg kg−1 for Zn, 4.9 and 29.0 mg kg−1 for Cu, 6.1–26.2 mg kg−1 for Pb, and 0.08 and 0.66 mg kg−1 for Cd. Metal input rates were initially estimated based on literature data. An additional, calibrated metal flux, tentatively attributed to mineral weathering, was necessary to fit the observed data. Dissolved organic carbon fluxes were estimated using a soil organic carbon model. The model adequately reproduced the EDTA-extractable (labile) concentrations when input rates were optimised and soil lateral mixing was invoked to account for the edge effect of mechanically ploughing the trial plots. The global average root mean square error (RMSE) was 2.7, and the average bias (overestimation) was −1.66, −2.18, −4.34 and −0.05 mg kg−1 for Zn, Cu, Pb and Cd, respectively. The calibrated model was used to project the long-term metal trends in field conditions (without soil lateral mixing), under stable climate and management practices, with soil organic carbon estimated by modelling and assumed trends in soil pH. Labile metal concentrations to 2100 were largely projected to remain near constant or to decline, except for some metals in plots receiving compost. Ecotoxicological thresholds (critical limits) were predicted to be exceeded presently under sewage sludge inputs and to remain so until 2100. Ecological risks were largely not indicated in the other plots, although some minor exceedances of critical limits were projected to occur for Zn before 2100. This study advances our understanding of TEs' long-term dynamics in agricultural fields, paving the way to quantitative applications of modelling at field scales

Leveraging environmental research and observation networks to advance soil carbon science

Soil organic matter (SOM) is a critical ecosystem variable regulated by interacting physical, chemical and biological processes. Collaborative efforts to integrate perspectives, data, and models from interdisciplinary research and observation networks can significantly advance predictive understanding of SOM. We outline how integrating three networks – the Long‐Term Ecological Research, with a focus on ecological dynamics, the Critical Zone Observatories with strengths in landscape/geologic context, and the National Ecological Observatory Network with standardized multi‐scale measurements—can advance SOM knowledge. This integration requires improved data dissemination and sharing, coordinated data collection activities, and enhanced collaboration between empiricists and modelers within and across networks

Co-located ecological data for exploring top- and subsoil carbon dynamics across grassland-woodland contrasts

Soil organic carbon (SOC) is a soil health indicator and understanding dynamics changing SOC stocks will help achieving net zero goals. Here we present four datasets featuring 11,750 data points covering co-located aboveground and below-ground metrics for exploring ecosystem SOC dynamics. Five sites across England with an established land use contrast, grassland and woodland next to each other, were rigorously sampled for aboveground (n = 109), surface (n = 33 soil water release curves), topsoil, and subsoil metrics. Commonly measured soil metrics were analysed in five soil increments for 0–1 metre (n = 4550). Less commonly measured soil metrics which were assumed to change across the soil profile were measured on a subset of samples only (n = 3762). Additionally, we developed a simple method for soil organic matter fractionation using density fractionation which is part of the less common metrics. Finally, soil metrics which may impact SOC dynamics, but with less confidence as to their importance across the soil profile were only measured on topsoil (~5–15 cm = mineral soil) and subsoil (below 50 cm) samples (n = 2567)

Aerodynamic Characterization of Conical Diffusers for Radial Turboexpanders Under Realistic Inlet Conditions

Radial inflow expander units are increasingly employed in both oil and gas upstream and downstream markets for energy saving purposes. While prominent attention is given to the performance of the expansion wheel, the downstream diffuser is scarcely covered in literature. In modern expanders, the gas entering the diffuser is typically high-speed, non-uniformly distributed from hub to shroud. Recovery factor and pressure loss coefficient are then affected by both the inlet gas conditions and the geometry of the system, including shaft end and divergence angle of the diffuser. In the present work, the application of computational methodologies to expander diffusers is initially assessed. A sensitivity analysis is then performed with respect to the inlet flow conditions and the diffuser shape. Trends of variation of recovery factor and loss coefficient are provided as a function of selected geometrical parameters and boundary conditions. It is shown that, starting from a non-optimized diffuser, an overall machine efficiency gain can be achieved. That performance improvement can be appreciated by the current market of expanders as a non-negligible competitive advantage

Earthworm species identification and counts at three long-term grassland-to-woodland land use contrasts across England

This dataset contains earthworm counts and identification from three long-term grassland-to-woodland land use contrasts across England between 2018 and 2021. Each land use contrast was assigned one grassland and one woodland plot, respectively. Each of the plots was further divided into three grids (grassland grids 1 to 3 / woodland grids 4 to 6) with grids 1 and 6 being the furthest apart. The contrast boundary is between grids 3 and 4. The three grassland-to-woodland contrasts were sampled once: Gisburn (Gisburn-1, Gisburn-2), and Kielder Forest. The earthworms were counted in 25 cm3 soil cubes and were identified to a species level. These measurements are co-located with estimates aboveground biomass production and litter layer depth, soil physical, chemical and biological properties (0-1 m), and soil hydraulic measurements (soil water release curves and hydraulic conductivity). A file is provided to connect all co-located measurements. This project was part of the UK-SCAPE programme which started in 2018 and was funded by the Natural Environment Research Council as National Capability (award number NE/R016429/1)

Plant aboveground net primary productivity estimates (2021) and litter layer depth measurements (2018-2019) at five long-term grassland-to-woodland land use contrasts across England

This dataset contains aboveground net primary productivity (ANPP) estimates and litter layer depth measurements from five long-term grassland-to-woodland land use contrasts across England between 2018 and 2021. Each metric was measured once at each site. Litter layer depth was measured between November 2018 and March 2019 . Leaves were sampled for ANPP estimates in 2021. Each land use contrast was assigned a grassland and a woodland plot respectively. Each of these plots was further divided into three grids (grassland grids 1 to 3 / woodland grids 4 to 6) with grids 1 and 6 being the furthest apart. The contrast boundary is between grids 3 and 4. In each plot, nine sampling locations were randomly sampled (three in each grid). The five land use contrasts were: Gisburn (Gisburn-1, Gisburn-2), Alice Holt, Wytham Woods, and Kielder Forest. ANPP (g dry mass m-2 yr-1) was estimated from measured leaf dry matter content of the two dominant species in each grassland and woodland plot. Litter layer depth (cm) was measured with a ruler in the field. ANPP estimates and litter layer depth measurements in this dataset are co-located with soil physical, chemical and biological properties (0-1 m), soil hydraulic measurements (soil water release curves and hydraulic conductivity), and earthworm counts and identification. A file is provided to connect all co-located measurements. This project was part of the UK-SCAPE programme which started in 2018 and was funded by the Natural Environment Research Council as National Capability (award number NE/R016429/1)

Soil water release curves and hydraulic conductivity measurements at four long-term grassland-to-woodland land use contrasts across England

This dataset contains soil water release curves and un-saturated hydraulic conductivity measurements from four long-term grassland-to-woodland land use contrasts across England between 2018 and 2021. Each land use contrast was assigned one grassland and one woodland plot respectively. Each of the plots was further divided into three grids (grassland grids 1 to 3 / woodland grids 4 to 6) with grids 1 and 6 being the furthest apart. The four grassland-to-woodland contrasts were located across England and sampled once : Gisburn (Gisburn-1, Gisburn-2), Wytham Woods, and Kielder Forest. Soil water release curves were measured for topsoil (0-5 cm) using the HYPROP system (UMS, Munich, Germany). Soil water infiltration (unsaturated hydraulic conductivity) was measured during soil sampling campaigns. Soil hydraulic measurements in this dataset are collocated with aboveground biomass production estimates and litter layer depth measurements, soil physical, chemical and biological properties (0-1 m), and earthworm counts and identification. A file is provided to connect all co-located measurements. This project was part of the UK-SCAPE programme which started in 2018 and was funded by the Natural Environment Research Council as National Capability (award number NE/R016429/1)

Zones of influence for soil organic matter dynamics: a conceptual framework for data and models

Soil organic matter (SOM) is an indicator of sustainable land management as stated in the global indicator framework of the United Nations Sustainable Development Goals (SDG Indicator 15.3.1). Improved forecasting of future changes in SOM is needed to support the development of more sustainable land management under a changing climate. Current models fail to reproduce historical trends in SOM both within and during transition between ecosystems. More realistic spatio‐temporal SOM dynamics require inclusion of the recent paradigm shift from SOM recalcitrance as an ‘intrinsic property’ to SOM persistence as an ‘ecosystem interaction’. We present a soil profile, or pedon‐explicit, ecosystem‐scale framework for data and models of SOM distribution and dynamics which can better represent land use transitions. Ecosystem‐scale drivers are integrated with pedon‐scale processes in two zones of influence. In the upper vegetation zone, SOM is affected primarily by plant inputs (above‐ and belowground), climate, microbial activity and physical aggregation and is prone to destabilization. In the lower mineral matrix zone, SOM inputs from the vegetation zone are controlled primarily by mineral phase and chemical interactions, resulting in more favourable conditions for SOM persistence. Vegetation zone boundary conditions vary spatially at landscape scales (vegetation cover) and temporally at decadal scales (climate). Mineral matrix zone boundary conditions vary spatially at landscape scales (geology, topography) but change only slowly. The thicknesses of the two zones and their transport connectivity are dynamic and affected by plant cover, land use practices, climate and feedbacks from current SOM stock in each layer. Using this framework, we identify several areas where greater knowledge is needed to advance the emerging paradigm of SOM dynamics—improved representation of plant‐derived carbon inputs, contributions of soil biota to SOM storage and effect of dynamic soil structure on SOM storage—and how this can be combined with robust and efficient soil monitoring

Soil physical, chemical, and biological properties (0-1 m) at five long-term grassland-to-woodland land use contrasts across England, 2018-2019

This dataset contains soil chemical, physical and biological properties for up to six soil layers between 0 and 100 cm, measured once at each of the five long-term grassland-to-woodland land use contrasts across England between November 2018 and March 2019. Each of the plots was further divided into three grids (grassland grids 1 to 3 / woodland grids 4 to 6) with grids 1 and 6 being the furthest apart. The contrast boundary is between grids 3 and 4. In each plot, nine sampling locations were randomly sampled (three in each grid). The five grassland-to-woodland contrasts were located across England: Gisburn (Gisburn-1, Gisburn-2), Alice Holt, Wytham Woods, and Kielder Forest. Common soil physical and chemical properties were measured; field water content, soil water content, electrical conductivity, bulk density, pH in DIW, pH in CaCl2, Loss-on-ignition, total soil carbon, total soil nitrogen, and total soil phosphorus. Less common properties were also measured; extractable soil nitrogen, dissolved organic carbon, soil aggregate sizes, and soil texture. And for specific soil cores these additional following properties were measured; soil density fractions and their carbon and nitrogen contents, cation exchange capacity, Sodium concentration, potassium concentration, calcium concentration, magnesium concentration, and extracellular enzyme activities. Derived metrics resulting from the bioinformatic processing of the raw sequence files are provided as part this dataset. The properties in this dataset are co-located with ANPP estimates, litter layer depth measurements, soil hydraulic measurements (soil water release curves and hydraulic conductivity), earthworm counts and identification. A file is provided to connect all co-located measurements

Consumo di suolo, dinamiche territoriali e servizi ecosistemici. Edizione 2023.

Il Rapporto “Consumo di suolo, dinamiche territoriali e servizi ecosistemici” è un prodotto del Sistema Nazionale per la Protezione dell’Ambiente (SNPA), che assicura le attività di monitoraggio del territorio e del consumo di suolo. Il Rapporto, insieme alla cartografia e alle banche dati di indicatori allegati, fornisce il quadro aggiornato dei processi di trasformazione della copertura del suolo e permette di valutare il degrado del territorio e l’impatto del consumo di suolo sul paesaggio e sui servizi ecosistemici