Publications

Understanding and managing uncertainty and variability for wastewater monitoring beyond the pandemic: Lessons learned from the United Kingdom National COVID-19 Surveillance Programmes

The COVID-19 pandemic has put unprecedented pressure on public health resources around the world. From adversity opportunities have arisen to measure the state and dynamics of human disease at a scale not seen before. Early in the COVID-19 epidemic scientists and engineers demonstrated the use of wastewater as a medium by which the virus could be monitored both temporally and spatially. In the United Kingdom this evidence prompted the development of National wastewater surveillance programmes involving UK Government agencies academics and private companies. In terms of speed and scale the programmes have proven to be unique in its efforts to deliver measures of virus dynamics across a large proportion of the populations in all four regions of the country. This success has demonstrated that wastewater-based epidemiology (WBE) can be a critical component in public health protection at regional and national levels and looking beyond COVID-19 is likely to be a core tool in monitoring and informing on a range of biological and chemical markers of human health; some established (e.g. pharmaceutical usage) and some emerging (e.g. metabolites of stress). We present here a discussion of uncertainty and variation associated with surveillance of wastewater focusing on lessons-learned from the UK programmes monitoring COVID-19 but addressing the areas that can broadly be applied to WBE more generally. Through discussion and the use of case studies we highlight that sources of uncertainty and variability that can impact measurement quality and importantly interpretation of data for public health decision-making are varied and complex. While some factors remain poorly understood and require dedicated research we present approaches taken by the UK programmes to manage and mitigate the more tractable components. This work provides a platform to integrate uncertainty management through data analysis quality assurance and modelling into the inevitable expansion of WBE activities as part of One Health initiatives.

Restoring degraded agricultural peatlands: how rewetting, biochar, and iron sulphate synergistically modify microbial hotspots and carbon storage

The online version contains supplementary material available at 10.1007/s42773-025-00501-y.

The Role of Estuarine Axial Convergent Fronts in Microplastic Dispersal

Further empirical evidence on popularity and electoral cycle effects

This paper empirically examines the hypothesis that popularity is typified by ‘electoral cycle effects’. We suggest that if the data is filtered, on the basis of a model assuming informed voters, there is no evidence for the electoral cycle hypothesis.

Tracing the Mineralisation Rates of C, N and S from Cysteine and Methionine in a Grassland Soil: A <sup>14</sup>C and <sup>35</sup>S Dual-Labelling Study

Cysteine (Cys) and Methionine (Met) represent the two main sulphur (S)-containing amino14 acids found in soil solution. Although general measures of S cycling (e.g., sulfatase activity) provide valuable information concerning the cycling of labile organic S in soil, detailed information regarding the microbial transformation pathways of Cys and Met at a molecular level remain poorly characterised. Therefore, in this study a 14C and 35S dual-isotopic labelling approach was used to trace the fate of C and S derived from Cys and Met in an agricultural grassland soil over a 7-day incubation period. Microbial biomass C, N, and S were analysed by the CHCl3 fumigation-extraction method, and CO2 evolution along with inorganic nutrient release (NH4 + , NO3 - and SO4 2-) were also measured. We then imposed an excess of C as glucose, or excess NPS (as NH4NO3, KH2PO4 and K2SO4) to investigate whether the Cys and Met mineralization process was affected by manipulating C, N and S availability in the soil solution. Our results showed that after 168 h, 2.7 – 19.5% of the 14C derived from Cys and Met had been immobilised in the microbial biomass, 67.2 – 89.2% had been respired as 14CO2 while the recovery of 35S label in the soil microbial biomass ranged from 11.9 – 41.8%. Overall, our results indicated that microbial communities have a high capacity to utilize Cys and Met but that they enter multiple metabolic pathways once inside the cell. While some of the amino acids may be directly used in protein synthesis, other metabolic pathways lead to NH4 + and SO4 2- being released back into the soil with the NH4 + then rapidly converted to NO3 - by the nitrifier community. The resulting C-skeletons were dissimilated and used to produce energy, leading to the release of 14CO2. The significant differences in C, N and S mineralization processing demonstrate a decoupling of the S and C cycles at the molecular level. Further, glucose-C addition shifted the allocation of C inside the cell to more catabolic processes and greater mineralization, while in comparison inorganic N, P and S availability had much less effect on resource partitioning.

Bioreduction of Sheep Carcasses Effectively Contains and Reduces Pathogen Levels under Operational and Simulated Breakdown Conditions

Options for the storage and disposal of animal carcasses are extremely limited in the EU after the introduction of the EU Animal By-products Regulations (ABPR; EC/1774/2002), leading to animosity within the livestock sector and the call for alternative methods to be validated. Novel storage technologies such as bioreduction may be approved under the ABPR provided that they can be shown to prevent pathogen proliferation. We studied the survival of Enterococcus faecalis, Salmonella spp., E. coli O157 and porcine parvovirus in bioreduction vessels containing sheep carcasses for approximately 4 months. The vessels were operated under two different scenarios: (A) where the water within was aerated and heated to 40 °C, and (B) with no aeration or heating, to simulate vessel failure. Microbial analysis verified that pathogens were contained within the bioreduction vessel and indeed reduced in numbers with time under both scenarios. This study shows that bioreduction can provide an effective and safe on-farm storage system for livestock carcasses prior to ultimate disposal. The findings support a review of the current regulatory framework so that bioreduction is considered for approval for industry use within the EU.

Moss-cyanobacteria associations as biogenic sources of nitrogen in boreal forest ecosystems

The biological fixation of atmospheric nitrogen (N) is a major pathway for available N entering ecosystems. In N-limited boreal forests, a significant amount of N2 is fixed by cyanobacteria living in association with mosses, contributing up to 50 % to the total N input. In this review, we synthesize reports on the drivers of N2 fixation in feather moss-cyanobacteria associations to gain a deeper understanding of their role for ecosystem-N-cycling. Nitrogen fixation in moss-cyanobacteria associations is inhibited by N inputs and therefore, significant fixation occurs only in low N-deposition areas. While it has been shown that artificial N additions in the laboratory as well as in the field inhibit N2 fixation in moss-cyanobacteria associations, the type, as well as the amounts of N that enters the system, affect N2 fixation differently. Another major driver of N2 fixation is the moisture status of the cyanobacteria-hosting moss, wherein moist conditions promote N2 fixation. Mosses experience large fluctuations in their hydrological status, undergoing significant natural drying and rewetting cycles over the course of only a few hours, especially in summer, which likely compromises the N input to the system via N2 fixation. Perhaps the most central question, however, that remains unanswered is the fate of the fixed N2 in mosses. The cyanobacteria are likely to leak N, but whether this N is transferred to the soil and if so, at which rates and timescales, is unknown. Despite our increasing understanding of the drivers of N2 fixation, the role moss-cyanobacteria associations play in ecosystem-N-cycling remains unresolved. Further, the relationship mosses and cyanobacteria share is unknown to date and warrants further investigation.

Projected Increases in Precipitation Are Expected To Reduce Nitrogen Use Efficiency and Alter Optimal Fertilization Timings in Agriculture in the South East of England

Nitrogen fertilization is vital for productive agriculture and efficient land use. However, globally, approximately 50% of the nitrogen applied is lost to the environment, causing inefficiencies, pollution, and greenhouse gas emissions. Rainfall and its effect on soil moisture are the major components controlling nitrogen losses in agriculture. Thus, changing rainfall patterns could accelerate nitrogen inefficiencies. We used a mechanistic modeling platform to determine how precipitation-optimal nitrogen fertilization timings and resulting crop nitrogen uptake have changed historically (1950–2020) and how they are predicted to change under the RCP8.5 climate scenario (2021–2069) in the South East of England. We found that historically, neither precipitation-optimal fertilization timings nor resulting plant uptake changed significantly. However, there were large year-to-year variations in both. In the 2030s, where it is projected to get wetter, precipitation-optimal fertilization timings are predicted to be later in the season and the resulting plant uptake noticeably lower. After 2040, the precipitation-optimal uptakes are projected to increase with earlier precipitation-optimal timings closer to historical values, corresponding to the projected mean daily rainfall rates decreasing to the historical values in these growing seasons. It seems that the interannual variation in precipitation-optimal uptake is projected to increase. Ultimately, projected changes in precipitation patterns will affect nitrogen uptake and precipitation-optimal fertilization timings. We argue that the use of bespoke fertilization timings in each year can help recuperate the reduced N uptake due to changing precipitation.

Disentangling the effect of sheep urine patch size and nitrogen loading rate on cumulative N2O emissions

Ruminant urine nitrogen (N) concentration and volume are important parameters influencing the size and N loading rate of urine patches deposited to soil. Such parameters can influence N cycling and emissions of the greenhouse gas, nitrous oxide (N2O) from grazed grassland, yet, there is limited information on the effect of these parameters within typical ranges reported for sheep. We used an automated, high-frequency gas monitoring system to investigate N2O emissions from varying urine N application rates and patch sizes under field conditions. Using artificial sheep urine, we manipulated urine N concentration to provide two urine N application rates (4 and 16 g N/L; equivalent to 200 and 800 kg N/ha). We investigated the effect of urine patch size with equal N application rates (4 × 125 cm2 vs 500 cm2, at 200 and 800 kg N/ha) and the effect of patch size with unequal N application rates, but the same total amount of N applied (62.5 mL over 125 cm2 at 800 kg N/ha and 250 mL over 500 cm2 at 200 kg N/ha). Cumulative emissions of N2O generally increased with N loading rate, whether applied as one large urine patch or four smaller ones. Cumulative N2O emissions increased when the N was applied in four smaller urine patches compared with one large patch; this difference was significant at 800 kg N/ha, but not at 200 kg N/ha. When the total amount of N applied was held constant (1 g of N), the amount of N2O released was similar when urine was applied as a high N concentration small patch (800 kg N/ha) compared with a low N concentration large patch (200 kg N/ha). Urine N2O emission factors in this study were, on average, 10 times lower than the IPCC default of 1% for sheep excreta. This research clearly demonstrates that the chemical and physical nature of the urine patch influences N2O emissions, yet further research is required to gather more data on typical sheep urine volumes (individual and daily), urination frequency, urine N concentrations and the typical volumes of soil influenced by urine deposition, to provide more accurate estimates of emissions from sheep grazed pastures.

COVID-19 Plane Infection Risks

Cross-sectional survey results from a COVID19 plane infection risk survey conducted between the 22^nd to 23^rd October, 2020. Participants (<em>n</em> = 2103) were aged 18 years or older, were living in the UK and had undertaken foreign air travel. The survey consisted of 18 closed-ended questions, with seventeen of the questions addressing issues associated with travelling by air and 11 questions addressing specific demographic topics. The questionnaire was designed by the research team, consisting of environmental microbiologists, public health specialists and social scientists, based on the study objectives and incorporating information from previous studies on same topic. The draft questionnaire was then tested on an expert panel, a panel of non-experts, a local ethics committee. First, perceived risks, concerns, and subjective knowledge of COVID-19 symptoms were measured using 16 options that included 14 actual symptoms and 2 which were not. Other questions about perception and risk were measured by statements with a 5-point Likert scale (e.g. strongly disagree to strongly agree).

Physical properties of nursery potting-mixtures

The bulk density, total porosity, air porosity and water-holding capacity of mixtures of equal parts of either sand or scoria with peat moss, pinebark, poppy straw and sawdust can be predicted from the respective properties of the ingredients. Total porosity of the media was inversely correlated to bulk density, but there is no clear correlation between air porosity and bulk density. Air porosity increased with pot size.

The Effect of LIX 63 Hydroxyoxime Degradation Products on Kinetics-Based Metal Extraction

The potential of the LIX® 63 hydroxyoxime/Versatic 10 combination to kinetically directly separate cobalt (1 g/L) from a nickel rich (20 g/L) synthetic leach solution while rejecting impurities has been highlighted previously. In the present work, the stability of the LIX 63 hydroxyoxime has been assessed under conditions relevant to a commercially prospective kinetics-based operation, and the results compared with those obtained in previously investigated equilibrium-based systems. Importantly, no adverse effect of the four main hydroxyoxime degradation products on metal extraction and stripping kinetics was found, even when these were added at high concentrations.

Macrozamia johnsonii, a new species of Macrozamia section Macrozamia (Zamiaceae) from northern New South Wales

Macrozamia johnsonii

Comparative assessment of Nanotrap and polyethylene glycol-based virus concentration in wastewater samples

Wastewater-based epidemiology is now widely used in many countries for the routine monitoring of SARS-CoV-2 and other viruses at a community level. However, efficient sample processing technologies are still under investigation. In this study, we compared the performance of the novel Nanotrap® Microbiome Particles (NMP) concentration method to the commonly used polyethylene glycol (PEG) precipitation method for concentrating viruses from wastewater and their subsequent quantification and sequencing. For this, we first spiked wastewater with SARS-CoV-2, influenza and measles viruses and norovirus and found that the NMP method recovered 0.4%–21% of them depending on virus type, providing consistent and reproducible results. Using the NMP and PEG methods, we monitored SARS-CoV-2, influenza A and B viruses, RSV, enteroviruses and norovirus GI and GII and crAssphage in wastewater using quantitative PCR (qPCR)-based methods and next-generation sequencing. Good viral recoveries were observed for highly abundant viruses using both methods; however, PEG precipitation was more successful in the recovery of low-abundance viruses present in wastewater. Furthermore, samples processed with PEG precipitation were more successfully sequenced for SARS-CoV-2 than those processed with the NMP method. Virus recoveries were enhanced by high sample volumes when PEG precipitation was applied. Overall, our results suggest that the NMP concentration method is a rapid and easy virus concentration method for viral targets that are abundant in wastewater, whereas PEG precipitation may be more suited to the recovery and analysis of low-abundance viruses and for next generation sequencing.

Innovations in soil science to address global grand challenges

This Special Issue presents a collection of papers commissioned to celebrate the UK Centre for Doctoral Training (CDT) in soil science known as 'STARS' (Soils Training And Research Studentships). The collection was written by emerging scientists and their collaborating supervisory teams. The call for papers was principally aimed at STARS students, but submissions were also encouraged from students in the wider UK soils community, who are also represented. The STARS CDT was originally commissioned in 2015 as part of a funding collaboration between the UK Natural Environment Research Council and the UK Biotechnology and Biological Science Research Council (BBSRC). The paper by Haygarth et al. (2021) provides a reflection on the STARS CDT experience, exploring what can be learnt from the new pedagogic approach. It describes how a discipline-focussed doctoral centre is a novel and unique way of teaching and learning soil science, proposing that this might be a model for future post graduate soil science teachers to learn from, in order to continually improve and innovate in the way we train our PhD students. In total, the Special Issue contains 17 papers, of which 15 appear in hard copy (incidentally, the last hard copy issue of the European Journal of Soil Science before conversion to solely on-line publication). All but one of the papers (Haygarth et al., 2021) are student-led, with three by non-STARS students (Jonah Prout, Yan Ma and Melanie Armbruster). The papers loosely fall into three categories: (1) Those involving local-scale controlled experiments and method development (seven papers), (2) those focussed on empirical analyses of large-scale datasets (six papers) and (3) those that involve a meta-analyses of previously published literature (three papers). In the first category, Chris McCloskey contributes two papers as lead author. In the first paper (McCloskey et al., 2020), a field system is presented for measuring plant and soil carbon fluxes using stable isotope methods, with sufficient precision to resolve diurnal and seasonal patterns. In the companion paper, the field system is used to demonstrate the importance of allowing for transient variation in plant and soil δ13C end members in partitioning fluxes from net ecosystem respiration (McCloskey et al., 2021). Ma et al. (2021) assessed the relative efficacy of nitrification inhibitors in a highly nitrifying soil and, like McCloskey, used carbon-labelling techniques to help achieve this. Dan Evans takes us to the core of soil formation, using a new technique of cosmogenic radionuclide analysis (Evans et al., 2021) with a conclusion that questions the accuracy of our existing soil formation knowledge, arguing that we must consider the bulk density profile of the overlying soil. At a slightly larger scale, 'Bee' Burak et al. (2020) uses an inductive mesocosm-based assessment to study how root hairs affect soil erosion by simulated rainfall. In similar controlled conditions, Corina Lees et al. (2020) used a growth room to control her climate change study in selecting plant traits for soil erosion control in grassed waterways. Marta Cattin et al. (2021) also uses controlled conditions with a 21-day laboratory microcosm incubation in order to assess the fate of soil carbon following the application of anaerobic digestate. In the second category, Fiona Seaton et al. (2020) uses an empirical data-driven analysis based on national (Welsh) monitoring of soil indicators to reflect on soil health, using large-scale data analyses (over 1350 topsoils) to understand the state and change of soils at a national scale. Her work shows the importance of land-use management in determining the soil health and functional capacity of soils. In an empirical approach not dissimilar, Armbruster et al. (2020) has a focus on bacterial and archaeal taxa as potential indicators of soil restoration across grasslands. The work highlights that microbial taxon are among the most sensitive indicators of soil restoration. Paul George et al. (2020) studied anaerobes and sulphate-reducing bacteria in relation to pH across varied land uses, using a nationwide 'metabarcoding' dataset from 436 sites belonging to seven contrasting temperate land uses. Andrew Tweedie et al. (2021) tested the hypothesis that phosphorus forms and functions in agricultural soils have changed over a period of 50–70 years, using topsoils from 35 agricultural sites in Northeast Scotland, compared at 'original' and 'resampled' timepoints. The paper by Hannah Cooper (2021) uses a broadly similar 'long-term' sampling approach and considers how long-term zero-tillage enhances the protection of soil carbon in tropical agriculture, studying soil samples collected from experimental fields in Botucatu, Brazil, which had been under zero-tillage for 2, 15 and 31 years. The paper by Prout et al. (2020) focusses on soil organic matter and proposes an index approach based on organic carbon-to-clay ratio. Again, like the above papers this work was empirically based, using 3809 sites from the National Soil Inventory of England and Wales. In the third category, Harry Barrat studied the impact of drought and rewetting on nitrous oxide emissions from soil in temperate and Mediterranean climates (Barrat et al., 2020). The method used the first meta-analysis and synthesis of the literature. Anchen Kehler et al. (2021) also applied a literature-based approach to her work, trying to predict how soil phosphorus will react to climate change. Finally in a wonderful collaborative article between the STARS students, Mihai Cimpoiasu et al. (2021) was first author on a reflective consideration of future priorities for soil science: 'Comparing perspectives from scientists and stakeholders'. Soil science has never seemed so topical, providing services underpinning our existence (Haygarth & Ritz, 2009) while addressing sustainable development and global grand challenges (Lal et al., 2021). It is thus timely to see this collection led by early career scientists on Innovations in Soil Science to Address Global Grand Challenges. Moreover, it is encouraging, not only because of the diversity of research findings themselves, but because of the promise it shows for our future capacity to deliver the discipline. Data sharing is not applicable to this article as no new data were created or analyzed in this study.

Evaluation of Dissolved Organic Carbon as a Soil Quality Indicator in National Monitoring Schemes

Background Monitoring the properties of dissolved organic carbon (DOC) in soil water is frequently used to evaluate changes in soil quality and to explain shifts in freshwater ecosystem functioning. Methods Using >700 individual soils (0–15 cm) collected from a 209,331 km2 area we evaluated the relationship between soil classification (7 major soil types) or vegetation cover (8 dominant classes, e.g. cropland, grassland, forest) and the absorbance properties (254 and 400 nm), DOC quantity and quality (SUVA, total soluble phenolics) of soil water. Results Overall, a good correlation (r2 = 0.58) was apparent between soil water absorbance and DOC concentration across the diverse range of soil types tested. In contrast, both DOC and the absorbance properties of soil water provided a poor predictor of SUVA or soluble phenolics which we used as a measure of humic substance concentration. Significant overlap in the measured ranges for UV absorbance, DOC, phenolic content and especially SUVA of soil water were apparent between the 8 vegetation and 7 soil classes. A number of significant differences, however, were apparent within these populations with total soluble phenolics giving the greatest statistical separation between both soil and vegetation groups. Conclusions We conclude that the quality of DOC rather than its quantity provides a more useful measure of soil quality in large scale surveys.

Carbon dioxide fluxes at an intensively cultivated temperate lowland peatland in the East Anglian Fens, UK

. This study reports the first recorded CO2 flux measurements of a drained and intensively cultivated lowland peatland in the East Anglian Fens (UK) using the eddy covariance technique. Measurements were made over a complete lettuce crop rotation and a subsequent fallow period. Maximum average daytime CO2 uptake and nocturnal loss rates were −10.39 and 7.63 μmol CO2 m−2 s−1, respectively. Daily CO2 budgets ranged from a net loss of 4.7 to a small net uptake of −1.23 g CO2-C m−2 d−1. Total vertical land/atmosphere CO2 losses were estimated at 227.11 ± 46.5 g CO2-C m−2 for a~120 day measurement period. Losses over a sixty day interval between field preparation and disking of the field at the end of the crop cycle were 74.22 ± 18.8 g CO2-C m−2. The site lost 152.89 ± 30.6 g CO2-C m−2 d−1 during a sixty day fallow period. Net ecosystem production was estimated at 117.72 ± 18.8 g CO2-C m−2 during the crop cycle and 270.61 ± 46.49 g CO2-C m−2 for the entire measurement period when harvested crop exports were accounted for. These results represent the first micrometeorological measurements obtained over degraded lowland peatland in Britain, and illustrate the scale of CO2 losses associated with agricultural production on temperate organic soils.

Function and mechanism of organic anion exudation from plant roots

The rhizosphere is the zone of soil immediately surrounding plant roots that is modified by root activity. In this critical zone, plants perceive and respond to their environment. As a consequence of normal growth and development, a large range of organic and inorganic substances are exchanged between the root and soil, which inevitably leads to changes in the biochemical and physical properties of the rhizosphere. Plants also modify their rhizosphere in response to certain environmental signals and stresses. Organic anions are commonly detected in this region, and their exudation from plant roots has now been associated with nutrient deficiencies and inorganic ion stresses. This review summarizes recent developments in the understanding of the function, mechanism, and regulation of organic anion exudation from roots. The benefits that plants derive from the presence of organic anions in the rhizosphere are described and the potential for biotechnology to increase organic anion exudation is highlighted.

Mycorrhizal infection of barley roots and its effect upon phosphorus uptake.

No abstract is provided for this article.