1
|
Feng J, Burke IT, Sepúlveda Olea FE, Chen X, Stewart DI. Distribution and speciation of Cu and Zn near spring barley (Hordeum vulgare) roots in digested sewage sludge-amended soil. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2025; 47:172. [PMID: 40221955 PMCID: PMC11994537 DOI: 10.1007/s10653-025-02482-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2025] [Accepted: 03/25/2025] [Indexed: 04/15/2025]
Abstract
Risk management for agricultural use of digested sewage sludge requires better understanding of the behaviour and fate of contaminant metals in the plant root zone. A study employing rhizo-pot and plug-tray experiments was conducted to identify the zone near spring barley roots (Hordeum vulgare) where concentration and speciation of Cu and Zn are affected. Cu and Zn bonding environments in the root epidermis/cortex and vascular tissue were also identified. In the digested sludge-amended soil, spring barley absorbed Cu only from the immediate vicinity of the roots (<< 1 mm), but Zn was taken up from further afield (> 1 mm). In the rhizosphere Cu was predominately present as Cu(I) oxides or as Cu(II) absorbed/bonded to phosphate, whereas Zn was present as Zn(II) in inner-sphere complexes with metal oxide surfaces, as Zn(II) sulphides or Zn(II) bonded to/incorporated into carbonates. Cu taken-up by spring barley roots was largely sequestered in the root epidermis and/or cortex predominately in the coordination environments similar to those seen in the rhizosphere. Only a small proportion of the Cu was translocated into the vascular tissue (where it is in the same two bonding environments). Zn taken-up by spring barley roots was present as Zn(II) sulphides, Zn(II) absorbed to/incorporated into carbonates, or Zn(II)-organic complexes. Zn was readily translocated from roots to shoots. Better understanding of these differences in the mobility and uptake of Cu and Zn in sludge-amended agricultural soils could be used to undertake element specific risk assessments.
Collapse
Affiliation(s)
- Jianting Feng
- School of Civil Engineering, University of Leeds, Leeds, LS2 9JT, UK.
- Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing, 210024, Jiangsu, China.
| | - Ian T Burke
- School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK
| | | | - Xiaohui Chen
- School of Civil Engineering, University of Leeds, Leeds, LS2 9JT, UK
| | - Douglas I Stewart
- School of Civil Engineering, University of Leeds, Leeds, LS2 9JT, UK
| |
Collapse
|
2
|
Llanos J, Hipperson H, Horsburgh G, Lappage MG, Maher KH, Burke T, Leake JR, Watt PJ. Environmental DNA is more effective than hand sorting in evaluating earthworm biodiversity recovery under regenerative agriculture. THE SCIENCE OF THE TOTAL ENVIRONMENT 2025; 968:178793. [PMID: 39978058 DOI: 10.1016/j.scitotenv.2025.178793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2024] [Revised: 02/04/2025] [Accepted: 02/06/2025] [Indexed: 02/22/2025]
Abstract
Regenerating soil biodiversity can help to reverse declines in soil health caused by cultivation and continuous arable cropping, and support sustainable food production and agro-ecosystem services. Earthworms are key functional components of soil biodiversity, with different ecological categories and species delivering specific beneficial soil functions. Conventional monitoring by hand-sorting from soil pits is highly labour intensive, can reliably identify only adults to species, and may under-record anecics (deep-burrowers). Here, we compare soil environmental DNA (eDNA) metabarcoding using two different primer sets and next-generation sequencing, with earthworm hand-sorting from standard soil-pits, in four conventionally managed arable fields into which strips of grass-clover ley had been introduced three years earlier. Earthworm populations had been recorded by hand-sorting in the previous three years and our goal was to assess the effects of the three-year leys compared to arable cropping using both hand-sorting and eDNA. The eDNA method found the same eight earthworm species as hand-sorting, but had greater power for detecting anecic earthworms and quantifying local species richness. Earthworm abundance increased by over 55% into the third year of the leys, surpassing abundances in adjacent permanent grasslands, helping to explain the observed soil health regeneration. Both overall relative read abundances and site occupancy proportions of earthworm eDNA were found to have potential as proxies for abundance, and the performance of each of these measures and the implications for further work are discussed. We show that eDNA can improve earthworm diversity monitoring and recommend its wider use both to better understand soil management effects on earthworm populations, and to guide agricultural policy and practice decisions affecting soil health.
Collapse
Affiliation(s)
- J Llanos
- Ecology and Evolutionary Biology, School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK; NERC Environmental Omics Facility, Ecology and Evolutionary Biology, School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK.
| | - H Hipperson
- NERC Environmental Omics Facility, Ecology and Evolutionary Biology, School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK.
| | - G Horsburgh
- NERC Environmental Omics Facility, Ecology and Evolutionary Biology, School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK
| | - M G Lappage
- Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - K H Maher
- NERC Environmental Omics Facility, Ecology and Evolutionary Biology, School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK.
| | - T Burke
- Ecology and Evolutionary Biology, School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK; NERC Environmental Omics Facility, Ecology and Evolutionary Biology, School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK.
| | - J R Leake
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK.
| | - P J Watt
- Ecology and Evolutionary Biology, School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK.
| |
Collapse
|
3
|
Feng J, Burke IT, Chen X, Stewart DI. Evolution of Cu and Zn speciation in agricultural soil amended by digested sludge over time and repeated crop growth. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:54738-54752. [PMID: 39215926 DOI: 10.1007/s11356-024-34784-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2024] [Accepted: 08/19/2024] [Indexed: 09/04/2024]
Abstract
Metals such as Zn and Cu present in sewage sludge applied to agricultural land can accumulate in soils and potentially mobilise into crops. Sequential extractions and X-ray absorption spectroscopy results are presented that show the speciation changes of Cu and Zn sorbed to anaerobic digestion sludge after mixing with soils over three consecutive 6-week cropping cycles, with and without spring barley (Hordeum vulgare). Cu and Zn in digested sewage sludge are primarily in metal sulphide phases formed during anaerobic digestion. When Cu and Zn spiked sludge was mixed with the soil, about 40% of Cu(I)-S phases and all Zn(II)-S phases in the amended sludge were converted to other phases (mainly Cu(I)-O and outer sphere Zn(II)-O phases). Further transformations occurred over time, and with crop growth. After 18 weeks of crop growth, about 60% of Cu added as Cu(I)-S phases was converted to other phases, with an increase in organo-Cu(II) phases. As a result, Cu and Zn extractability in the sludge-amended soil decreased with time and crop growth. Over 18 weeks, the proportions of Cu and Zn in the exchangeable fraction decreased from 36% and 70%, respectively, in freshly amended soil, to 28% and 59% without crop growth, and to 24% and 53% with crop growth. Overall, while sewage sludge application to land will probably increase the overall metal concentrations, metal bioavailability tends to reduce over time. Therefore, safety assessments for sludge application in agriculture should be based on both metal concentrations present and their specific binding strength within the amended soil.
Collapse
Affiliation(s)
- Jianting Feng
- School of Civil Engineering, University of Leeds, Leeds, LS2 9JT, UK.
| | - Ian T Burke
- School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK
| | - Xiaohui Chen
- School of Civil Engineering, University of Leeds, Leeds, LS2 9JT, UK
| | - Douglas I Stewart
- School of Civil Engineering, University of Leeds, Leeds, LS2 9JT, UK
| |
Collapse
|
4
|
Edlinger A, Garland G, Banerjee S, Degrune F, García-Palacios P, Herzog C, Pescador DS, Romdhane S, Ryo M, Saghaï A, Hallin S, Maestre FT, Philippot L, Rillig MC, van der Heijden MGA. The impact of agricultural management on soil aggregation and carbon storage is regulated by climatic thresholds across a 3000 km European gradient. GLOBAL CHANGE BIOLOGY 2023; 29:3177-3192. [PMID: 36897740 DOI: 10.1111/gcb.16677] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 02/07/2023] [Indexed: 05/03/2023]
Abstract
Organic carbon and aggregate stability are key features of soil quality and are important to consider when evaluating the potential of agricultural soils as carbon sinks. However, we lack a comprehensive understanding of how soil organic carbon (SOC) and aggregate stability respond to agricultural management across wide environmental gradients. Here, we assessed the impact of climatic factors, soil properties and agricultural management (including land use, crop cover, crop diversity, organic fertilization, and management intensity) on SOC and the mean weight diameter of soil aggregates, commonly used as an indicator for soil aggregate stability, across a 3000 km European gradient. Soil aggregate stability (-56%) and SOC stocks (-35%) in the topsoil (20 cm) were lower in croplands compared with neighboring grassland sites (uncropped sites with perennial vegetation and little or no external inputs). Land use and aridity were strong drivers of soil aggregation explaining 33% and 20% of the variation, respectively. SOC stocks were best explained by calcium content (20% of explained variation) followed by aridity (15%) and mean annual temperature (10%). We also found a threshold-like pattern for SOC stocks and aggregate stability in response to aridity, with lower values at sites with higher aridity. The impact of crop management on aggregate stability and SOC stocks appeared to be regulated by these thresholds, with more pronounced positive effects of crop diversity and more severe negative effects of crop management intensity in nondryland compared with dryland regions. We link the higher sensitivity of SOC stocks and aggregate stability in nondryland regions to a higher climatic potential for aggregate-mediated SOC stabilization. The presented findings are relevant for improving predictions of management effects on soil structure and C storage and highlight the need for site-specific agri-environmental policies to improve soil quality and C sequestration.
Collapse
Affiliation(s)
- Anna Edlinger
- Agroscope, Plant-Soil Interactions Group, Zurich, Switzerland
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Gina Garland
- Agroscope, Plant-Soil Interactions Group, Zurich, Switzerland
- Department of Environmental System Science, ETH Zurich, Zurich, Switzerland
| | - Samiran Banerjee
- Department of Microbiological Sciences, North Dakota State University, Fargo, North Dakota, USA
| | - Florine Degrune
- Institute of Biology, Freie Universität Berlin, Berlin, Germany
- Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, Germany
- Soil Science and Environment Group, Changins, University of Applied Sciences and Arts Western Switzerland, Nyon, Switzerland
| | - Pablo García-Palacios
- Instituto de Ciencias Agrarias, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Chantal Herzog
- Agroscope, Plant-Soil Interactions Group, Zurich, Switzerland
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - David Sánchez Pescador
- Departamento de Biología y Geología, Física y Química Inorgánica, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, Móstoles, Spain
| | - Sana Romdhane
- Department of Agroecology, INRA, AgroSup Dijon, University Bourgogne Franche Comte, Dijon, France
| | - Masahiro Ryo
- Institute of Biology, Freie Universität Berlin, Berlin, Germany
- Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, Germany
- Leibniz Centre for Agricultural Landscape Research (ZALF), Müncheberg, Germany
- Brandenburg University of Technology Cottbus-Senftenberg, Cottbus, Germany
| | - Aurélien Saghaï
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Sara Hallin
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Fernando T Maestre
- Instituto Multidisciplinar para el Estudio del Medio "Ramón Margalef", Universidad de Alicante, Alicante, Spain
- Departamento de Ecología, Universidad de Alicante, Alicante, Spain
| | - Laurent Philippot
- Department of Agroecology, INRA, AgroSup Dijon, University Bourgogne Franche Comte, Dijon, France
| | - Matthias C Rillig
- Institute of Biology, Freie Universität Berlin, Berlin, Germany
- Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, Germany
| | - Marcel G A van der Heijden
- Agroscope, Plant-Soil Interactions Group, Zurich, Switzerland
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| |
Collapse
|