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Wastewater treatment plants (WWTPs) are hot spots for the acquisition and spread of antimicrobial resistance (AMR). This regional-based study quantified antibiotic resistance genes (ARGs), mobile genetic elements (MGEs), and bacteria in hospital and community-derived wastewater and receiving environments, using high-throughput qPCR (HT-qPCR). This is the first study to apply Resistomap's Antibiotic Resistance Gene Index (ARGI) as a standardised metric to find the overall AMR level across different WWTPs. ARGI of WWTPs ranged from 2.0 to 2.3, indicating higher relative ARG levels than the mean European ARGI of 2.0, but lower than the global mean of 2.4. The highest diversity and abundance of ARGs were observed in untreated hospital and community wastewater. The reduction of total ARGs during wastewater treatment (0.2- 2 logs) and bacteria (0.3-1.5 logs) varied spatio-temporally across the WWTPs. Despite a decrease in ARG and bacterial abundance in treated effluents, substantial loads were still released into receiving environments. Notably, ARG levels in coastal sediments were comparable to those in untreated wastewater, and most ARGs were shared between wastewater and receiving environments, highlighting the impact of wastewater discharge on these ecosystems. Sewage outfall exposure increased ARGs in shellfish, emphasising risks to shellfish hygiene. This study provides evidence to inform policymaking, emphasising advanced wastewater treatment methods and combined sewer overflow (CSO) management to mitigate ARG release, protecting water users and the food chain.

The presence of SARS-CoV-2 in the feces of infected patients and wastewater has drawn attention, not only to the possibility of fecal-oral transmission but also to the use of wastewater as an epidemiological tool. The COVID-19 pandemic has highlighted problems in evaluating the epidemiological scope of the disease using classical surveillance approaches, due to a lack of diagnostic capacity, and their application to only a small proportion of the population. As in previous pandemics, statistics, particularly the proportion of the population infected, are believed to be widely underestimated. Furthermore, analysis of only clinical samples cannot predict outbreaks in a timely manner or easily capture asymptomatic carriers. Threfore, community-scale surveillance, including wastewater-based epidemiology, can bridge the broader community and the clinic, becoming a valuable indirect epidemiological prediction tool for SARS-CoV-2 and other pandemic viruses. This article summarizes current knowledge and discusses the critical factors for implementing wastewater-based epidemiology of COVID-19.

Microbial communities in agricultural soils underpin many ecosystem services including the maintenance of soil structure, food production, water purification and carbon storage. However, the impact of fertilization on the health of microbial communities is not well understood. This study investigates the spatial and temporal dynamics of nitrogen (N) transport away from a fertilizer granule with pore scale resolution. Specifically, we examined how soil structure and moisture content influence fertilizer derived N movement through the soil pore network and the subsequent impact of on soil microbial communities. We develop a mathematical model to describe N transport and reactions in soil at the pore-scale. Using X-ray Computed Tomography scans, we reconstructed a microscale description of a soil-pore geometry as a computational mesh. Solving two-phase water/air model produced pore-scale water distributions at 15, 30 and 70% water-filled pore volume. The N-speciation model considered ammonium (NH4 +), nitrate (NO3 −) and dissolved organic N (DON), and included N immobilization, ammonification and nitrification processes, as well as diffusion in soil solution. We simulated the dissolution of a fertilizer pellet and a pore scale N cycle at three different water saturations. To aid interpretation of the model results, microbial activity at a range of N concentrations was measured. The model showed that the diffusion and concentration of N in water films is critically dependent upon soil moisture and N species. We predict that the maximum NH4 + and NO3 − concentrations in soil solution around the pellet under dry conditions are in the order of 1 × 103 and 1 × 104 mol m−3 respectively, and under wet conditions 2 × 102 and 1 × 103 mol m−3, respectively. Supporting experimental evidence suggests that these concentrations would be sufficient to reduce microbial activity in the short-term in the zone immediately around the fertilizer pellet (ranging from 0.9 to 3.8 mm), causing a major loss of soil biological functioning. This model demonstrates the importance of pore-scale processes in regulating N movement and their interactions with the soil microbiome.

Agricultural plastic mulch films are a major source of plastic pollution of croplands. In China, which uses about 68% of the plastic mulch film produced globally (ca. 1.4 million tonnes y^-1), soils have been heavily contaminated with mulch fragments. Here, we collected a national dataset of macroplastic residues (> 5 mm) in soil, including 3145 sampling sites, and provincial plastic film usage from 1992 to 2019 in China, and we established a linear model between the residue amount and historical cumulative usage within each province. Using the model, we quantified the amount of macroplastic residues in Chinese croplands on a national scale during the past 30 years and predict plastic pollution until 2050. Our results reveal the total national amount of plastic mulch residue in 2020 to be 2.07 million tonnes with a 95% CI of [1.67, 2.58]. This accumulated amount of plastic in Chinese soils roughly equals the annual amount of plastic films used globally (2.08 million tonnes in 2018) and is about 8% of national historically used plastic mulch film (27.3 million tonnes) remaining in soil as legacy plastic. Plastic concentrations in Chinese croplands in 2020 range from 7.7 kg ha^-1 in Anhui to 399 kg ha^-1 in Xinjiang, with an average value of 119 kg ha^-1 (equivalent to 0.03 g kg^-1 soil). We predict that the total amount and average concentration of plastic residues in Chinese croplands will reach 6.24 million tonnes and 357 kg ha^-1 (equivalent to 0.1 g kg^-1 soil) in 2050 under current plastic usage. There is an urgent need for regulatory actions to control plastic pollution in Chinese agriculture.

Excess chemical fertilizer application results in substantial N2O emission. Manure application into agricultural soil can reduce chemical fertilizer input while maintaining crop yield. However, little is known about the potential effects of reduction in chemical fertilizer with green manure or organic manure on yield-scaled N2O emissions in orchards. A two-year experiment was carried out in a citrus orchard, including (i) chemical fertilizer (urea), 0%, 70%, 85% and 100% of N supplied, respectively (CK, C70, C85, CF), (ii) organic manure (rapeseed cake) incorporation with 0%, 70%, 85% and 100% of N supplied from chemical fertilizer (OM, OMC70, OMC85, OMCF), (iii) green manure (smooth vetch) incorporation with 0%, 70%, 85% and 100% of N supplied from chemical fertilizer (GM, GMC70, GMC85, GMCF) treatments. The soil physical-chemical properties, N2O emissions and yields were measured during 2018–2019. N2O emissions were 1.57 and 1.80 kg N ha−1 yr−1 under CF treatment in 2018 and 2019, respectively, and decreased by 25.4%−31.6% under C70, 32.5%−55.4% under OMC70 and OMC85 treatments and by 16.1–32.2% under GMC70 and GMC85 treatments. The 70% N rate of chemical fertilizer was the optimal N rate for maximizing yield in no manure, organic manure and green manure treatments, respectively. The C70, OMC70 and GMC70 treatments both significantly decreased yield-scaled N2O emission with the lowest emission in OMC70 treatment relative to CF treatment. N2O fluxes in OMC70 and OMC85 treatments were mainly controlled by the DOC/NO3 - ratio, while soil NH4 + was the dominant factor controlling N2O fluxes in GMC70 and GMC85 treatments, suggesting that more NH4 + provided from green manure than from organic manure contributed to higher N2O emission. We conclude that applying organic manure incorporation with 30% reductions of chemical fertilizer is a fertilizer management strategy worth pursuing for sustainable productivity and environmental protection in citrus orchards.

Phthalate acid esters (PAEs) are commonly used plastic additives, not chemically bound to the plastic that migrate into surrounding environments, posing a threat to environmental and human health. Dibutyl phthalate (DBP) and di(2-ethylhexyl) phthalate (DEHP) are two common PAEs found in agricultural soils, where degradation is attributed to microbial decomposition. Yet the impact of the plastic matrix on PAE degradation rates is poorly understood. Using 14C-labelled DBP and DEHP we show that migration from the plastic matrix into soil represents a key rate limiting step in their bioavailability and subsequent degradation. Incorporating PAEs into plastic film decreased their degradation in soil, DBP (DEHP) from 79% to 21% (9% to <1%), over four months when compared to direct application of PAEs. Mimicking surface soil conditions, we demonstrated that exposure to ultraviolet radiation accelerated PAE mineralisation twofold. Turnover of PAE was promoted by the addition of biosolids, while the presence of plants and other organic residues failed to promote degradation. We conclude that PAEs persist in soil for longer than previously thought due to physical trapping within the plastic matrix, suggesting PAEs released from plastics over very long time periods lead to increasing levels of contamination.

<List> <ListItem><ItemContent> ● Arable-ley rotations can alleviate soil degradation and erosion. </ItemContent></ListItem> <ListItem><ItemContent> ● Multispecies leys can improve livestock health and reduce greenhouse gas emissions. </ItemContent></ListItem> <ListItem><ItemContent> ● Ley botanical composition is crucial for determining benefits. </ItemContent></ListItem> <ListItem><ItemContent> ● Lack of livestock infrastructure in arable areas may prevent arable-ley uptake. </ItemContent></ListItem> <ListItem><ItemContent> ● Long-term (10–25 years) research is needed to facilitate evidence-based decisions. </ItemContent></ListItem></List> Agricultural intensification and the subsequent decline of mixed farming systems has led to an increase in continuous cropping with only a few fallow or break years, undermining global soil health. Arable-ley rotations incorporating temporary pastures (leys) lasting 1–4 years may alleviate soil degradation by building soil fertility and improving soil structure. However, the majority of previous research on arable-ley rotations has utilized either grass or grass-clover leys within ungrazed systems. Multispecies leys, containing a mix of grasses, legumes, and herbs, are rapidly gaining popularity due to their promotion in agri-environment schemes and potential to deliver greater ecosystem services than conventional grass or grass-clover leys. Livestock grazing in arable-ley rotations may increase the economic resilience of these systems, despite limited research of the effects of multispecies leys on ruminant health and greenhouse gas emissions. This review aims to evaluate previous research on multispecies leys, highlighting areas for future research and the potential benefits and disbenefits on soil quality and livestock productivity. The botanical composition of multispecies leys is crucial, as legumes, deep rooted perennial plants (e.g., <i>Onobrychis viciifolia</i> and <i>Cichorium intybus</i>) and herbs (e.g., <i>Plantago lanceolata</i>) can increase soil carbon, improve soil structure, reduce nitrogen fertilizer requirements, and promote the recovery of soil fauna (e.g., earthworms) in degraded arable soils while delivering additional environmental benefits (e.g., biological nitrification inhibition and enteric methane reduction). Multispecies leys have the potential to deliver biologically driven regenerative agriculture, but more long-term research is needed to underpin evidence-based policy and farmer guidance.

Commercial herbal leys (multispecies swards) are rapidly gaining popularity due to their potential to deliver an enhanced suite of ecosystem services. However, little is known about their impact on lamb production. A 2-ha split-field experiment using an herbal and grass-clover ley (0.33 ha paddock−1, n = 3 per sward) aimed to evaluate the effect of sward-type on forage quality and lamb productivity. Lambs (n = 40 per sward) were rotationally grazed over two experimental seasons: autumn 2020 (males) and spring 2021 (females). Sward quality was measured at the start of each grazing season. Liveweight gain and faecal egg counts (FEC) were measured at week 0, 4 and 6 in autumn and week 0, 4, 9 and 11 in spring. Blood samples were analysed after 11-weeks in spring to assess mineral status. General sward nutritional quality (e.g., crude protein) did not improve under the herbal ley, however, higher sward macro- and micronutrient concentrations were observed in both seasons. Spring liveweight gain was significantly greater in lambs grazing the herbal (172 ± 7 g d−1) vs. grass-clover ley (144 ± 7 g d−1), while autumn liveweight gain showed no difference. Spring lambs grazing the herbal ley compared to the grass-clover ley had elevated plasma cobalt (2.0 ± 0.1 nmol l−1 vs. 1.6 ± 0.1 nmol l−1) and selenium (0.7 ± 0.04 µmol l−1 vs. 0.5 ± 0.01 µmol l−1), with lower blood urea (7.7 ± 0.3 nmol l−1 vs. 10.4 ± 0.4 nmol l−1). Spring FEC scores were reduced by 78 % in herbal grazed lambs; there were no significant differences in autumn FEC from either sward. In conclusion, the herbal ley resulted in seasonal improvements in sward micronutrient content and lamb parasite burden, mineral status, and productivity.

No abstract is provided for this article.

Carbon-to-nitrogen ratio (C:N) has frequently been shown to be a good predictor of the speed of organic residue decomposition and N mineralization in soil. While this relationship appears to work well for complex organic materials (e.g. plant litter), its applicability to smaller organic substrates containing N remains unknown. Here we evaluated whether the intrinsic properties of amino acids and peptides could be used to predict their rate of microbial uptake and subsequent N mineralization. In an agricultural grassland soil we found that C:N, molecular weight, aromaticity and sulphur content provided poor indicators of amino acid bioavailabilityand subsequent NH4 + release into soil. We therefore hypothesize that the position of amino acids along microbial biosynthetic pathways together with internal demand for individual amino acids rather than their C or N content is the primary determinant of N mineralization.

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