Sewage sludge (SS) is a by-product of wastewater treatment processes (WWTPs) and is rich in organic matter and essential nutrients like nitrogen, phosphorus, and potassium, making it a potential fertilizer for agricultural use. However, its application is often limited due to the presence of pathogenic bacteria, viruses, metals, and organic contaminants that can accumulate in soils and crops, raising concerns about food safety. Sewage sludge is additionally challenging to handle due to its high moisture content, low density, and odor emission. To mitigate environmental risks and enhance its usability as a soil fertilizer, SS must be stabilized. Various techniques, including chemical, physical, and biological, can be used to stabilize SS. The addition of lime and composting has received particular attention among these techniques owing to the benefits they offer. Both methods effectively control and eliminate pathogens and reduce metal bioavailability, thus improving their agricultural utility. This review emphasizes the importance of using SS for agricultural purposes, placing particular focus on the procedures of composting and liming to stabilize and enhance the quality of SS, hence promoting its safety.

Background The application of animal slurry to the soil improves its quality, as manure contains many nutrients for plants. However, this could negatively impact the environment. Objective This field study investigated the effects of the addition of biochar after the mechanical separation of Whole pig Slurry (WS) into Solid (SF) and Liquid Fractions (LF) on Greenhouse Gases (GHG) emissions (N2O, CO2, and CH4) and ryegrass (Lolium multiflorum Lam. cv magnum) yield. Methods Biochar (1.0 kg m-2) was applied in plots alone or together with each of the three slurries (80 kg N ha-1) in a total of eight treatments with three replications, including just soil with and without biochar as controls. Soil properties, Greenhouse Gas (GHG) fluxes, and yield were measured during theautumn/winter growing season. Results The results showed that the addition of biochar to these three slurries significantly increased the soil pH and showed no impact on the other physicochemical properties. The GHG emissions were not significantly different between treatments with and without biochar. The N use efficiency increased significantly in SF > WS > LF, whereas no differences were observed among these three slurries with and without biochar. Conclusion It can be concluded that the addition of biochar combined with WS or SF/LF to sandy-loam soil appears to have no impact on GHG emissions and ryegrass yield during the autumn/winter season. Overall, this finding suggests that amounts higher than 1.0 kg m-2 of biochar combined with SF may need to be applied to soil to reduce GHG emissions and nitrate leaching and increase N use efficiency and crop yield.

Elevated concentrations of emerging contaminants (ECs), such as silver nanoparticles (Ag-NPs) and microplastics (MPs), are of great concern to aquatic environments. These ECs are released into freshwaters due to improper waste management and may pose risk to freshwater biota and associated ecosystem processes. Conversely, biochar (BC) and biochar nanoparticles (BC-NPs) are nature-based products (NBPs), reported to remove some contaminants from environmental samples, particularly soil. However, knowledge about their impacts on freshwater ecosystems, alone or in the presence of emerging contaminants, is lacking. We investigated the impacts of Ag-NPs and MPs (polyethylene) on stream-dwelling microbial communities involved in leaf-litter decomposition, as it is a key ecosystem process, sensitive to water quality. Also, the impacts of the naturebased products, BC and BC-NPs, were assessed in the absence and presence of Ag-NPs or MPs. Both, Ag-NPs and MPs had negative effects on aquatic fungal communities, reducing reproduction, species richness, and altering species contribution, as well as on leaf-litter decomposition in a concentration-dependent manner. Neither larger particles nor nanoparticles of biochar showed any adverse effects on microbial decomposition at any of the concentrations, suggesting their eco-compatible nature in freshwaters; rather, BC-NPs stimulated fungal sporulation and leaf-litter decomposition. Moreover, the presence of these NBPs attenuated the negative effects of the tested ECs in a concentration-dependent manner, with more pronounced effects against MPs. BC-NPs showed greater alleviation efficiency than BC in aquatic ecosystems. This study emphasizes the importance of stream detrital ecosystem in ecotoxicological assessments and potential role of nature-based resources to deal with emerging contaminants.

Copper (Cu) contamination in vineyard soils present environmental risks and affect the respective quality and ecosystem functions. This study evaluated the mitigation effect of different soil conditioners on Cu lability and ecotoxicity. A vineyard contaminated soil, relative to four treatments, with (1% of biochar-BioC, nanobiochar-nBioC and chitosan-Chit), and without (control) conditioner, was incubated for two months under controlled conditions, and copper lability was assessed by DTPA extraction. The ecotoxicity was evaluated by a behaviour test, using Eisenia fetida as biologic model, with avoidance as an endpoint (A%). All amendments reduced Cu availability, with DTPA-extractable Cu decreasing from 29.2 ± 0.3 mg kg⁻¹ (control) to 28.3 ± 0.2 (BioC), 27.5 ± 0.2 (nBioC), and 26.6 ± 0.1 mg kg⁻¹ (Chit) order. Avoidance responses were -68% (nBioC), -48% (BioC), 12% (control), and 62% (Chit). Despite decreasing Cu lability, chitosan promotes the strongest avoidance response, suggesting a potential biocidal effect on earthworms. Conversely, in BioC and nBioC treatments, pH increase, surface sorption, and Cu complexation factors can explain both reduced Cu bioavailability and enhanced ecological compatibility, especially for the nanobiochar due to its higher reactivity. For this, nanobiochar presented the most balanced performance, combining effective immobilization with lower ecotoxicological impact, suggesting its potential as a sustainable amendment for remediating Cu-contaminated vineyard soils.

As an environmentally friendly and carbon-rich material, biochar holds significant application potential in waste valorization, water pollution remediation, and carbon sequestration. In recent years, machine learning has emerged as a powerful data-driven tool and is being increasingly applied in biochar research. This review systematically summarizes the fundamental concepts, preparation methods, and key application areas of biochar, with a particular focus on recent advances in its roles in carbon footprint reduction and resource utilization. The applications of machine learning in process optimization, material design, and life cycle assessment are thoroughly discussed. Moreover, the challenges related to data acquisition, model interpretability, and interdisciplinary collaboration are critically analyzed. Importantly, the review highlights that biochar application can reduce total greenhouse gas emissions by 20%–70%, with carbon sequestration rates reaching up to 90% depending on feedstock and pyrolysis conditions. Machine learning models such as random forest and deep neural networks have achieved prediction accuracies exceeding 90% in forecasting biochar yield, surface area, and adsorption capacity, significantly improving design efficiency and environmental performance. Looking ahead, the integration of advanced techniques such as deep learning, multi-objective optimization, and self-supervised learning is expected to further enhance the environmental benefits and intelligent design of biochar, thereby offering strong technical support for global climate mitigation and the circular economy development.

This study explores methane emission trends across Greece, Armenia, and Rostov Oblast region of Russia from 2004 to 2023. Our analyses, based on remote sensing and advanced statistical techniques, showed a 1.3-1.8 °C increase in mean annual temperature over this 20-year period in all these three regions, with the highest and the lowest rates of annual warming in Armenia (0.104 °C) and Rostov Oblast of Russia (0.052 °C), respectively. Mean annual methane concentrations increased distinctly in these regions over this period. Greece showed the trend of highest correlations between methane emissions and temperatures, including mean annual and seasonal temperatures, highlighting substantial role of climate change in emission trends. The emission trends with on-ground observations revealed intricate connections between reduced precipitations, farming practices, waste disposal methods, and naturally occurring emissions in Greece. In contrast, Armenia exhibited weak correlations between temperature and methane emissions, with its farming, waste management, energy and manufacturing sectors playing a significant role in determining emission quantities. The Rostov Oblast of Russia demonstrated weaker association between methane emissions and temperatures than Greece and Armenia, with emission trends being primarily shaped by agricultural activities and natural discharges from wetlands. The forecast models predicted further rise in methane emissions over the 7-year period (2024-2030), with the highest elevation rate estimated for Russia. This study emphasizes the need for tailored mitigation strategies to address methane emissions effectively, considering region-specific factors. Advanced monitoring technologies provide crucial insights into the assessment and management of methane emissions in these diverse geomorphological regions.

The rapid increase in pig production has become a major contributor to environmental issues due to the mismanagement of organic waste. The sustainable and effective transformation of this waste into a fertilization resource has become an urgent topic for environmental protection, and new regulations have been imposed. The present study aimed to investigate the effects of different ratios of swine manure liquid (SML) and chemical fertilizers on soil phosphorus forms and microbial communities through field experiments cultivating spring wheat (cultivar “Jinqiang 10”) in Hebei, China. The results indicated that the application of SML in portions with traditional fertilizer can enhance soil pH and electrical conductivity (EC), as well as available phosphorus, particularly when the proportion of SML is high (SML ≥ 75%). Compared with CK, the available phosphorus content of group C3 increased by 22.3%. SML facilitated the transformation of stable phosphorus to unstable phosphorus, as well as the conversion of organic phosphorus to inorganic phosphorus. Additionally, SML increased the soil content of H2O-P, NaHCO3-Pi, and NaHCO3-Po, and promoted the conversion of NaOH-Po to NaHCO3-Po. Studies on bacterial diversity indicated that different fertilization treatments have no significant impact on the bacterial diversity in the 0–20 cm soil layer, whereas the dominant bacterial and fungal genera were positively correlated with the available phosphorus. The present study may facilitate the combined application of SML and chemical fertilizers for soil improvement and improve phosphorus availability.

The influence of chemical quality on decomposition was studied under Mediterranean conditions using the litter bag methodology. Litter of twenty-seven organic materials of different origins was enclosed in litter bags, buried, and periodically sampled during a 14-month period. The mass loss of each material was calculated, different empirical models of one and two pools were adjusted, and the respective constants were estimated. Linear regressions were established between the labile (ML) and recalcitrant (MR) mass loss pools and initial material characteristics to determine the best predictor of decomposition. The ML and MR pools were related to the presence of soluble or recalcitrant compounds, with values varying between 66.7-685 and 316-934 g kg-1, respectively. Materials with higher soluble compounds, such as PMM or LL, showed significantly higher ML values than CSS or OWM materials, with higher MR values where recalcitrant fractions were predominant. Various quality parameters were correlated with mass loss with best predictability of ML and MR presented by labile indicators as TAPPI soluble elements that explained 79% and 77% of variation results, respectively. For structural parameters, the best result was presented by total condensed tannins followed by lignin content that explained between 40% and 51% variation of ML and MR. Improved predictability was observed by integrating other labile indicators, like water soluble C and N and the respective ratio, or recalcitrant total condensed tannins and holocellulose, in ML (r2adj = 0.890***) and MR (r2adj = 0.866***) pool estimation, respectively.

Application of lithium has been increased in recent years due to its use in various modern gazettes and forced to find new reserves and extraction through mining. The mining process and improper disposal of lithium containing gazettes significantly added this element to the surrounding areas, especially to the terrestrial and soil ecosystems. The increasing concentration of lithium affected the soil biodiversity and altered behavior was expected for macro-organisms. Present study aimed to investigate the different concentrations of lithium salt (Li₂CO₃) on the behavior of the species of earthworm (Eisenia fetida), according to ISO 17512-1:2008 standards. In recent years, researches on biochars are drastically increased due to its unique role in soil health improvement. Thus, the biochar has been included in this work as a conditioning material to study the mitigation effects of lithium on earthworm (E. fetida) behaviour. The findings suggested that lithium promoted the earthworm avoidance on dose dependent manner while 1% (w/w) addition of biochar in soil mitigated the avoidance behaviour. These mitigating effects were corelated to certain soil physio-chemical properties change, better soil's buffering capacity against stress by lithium in presence of biochar. The findings of present study may force new investigation to restore the soil health and earthworm behaviour near the mining areas.

Biochar is being produced from biosolids waste of several industrial sectors, including Agri industries by pyrolysis process. Present investigation aims to evaluate the biochar produced from forest debris. Animal farming is a major agri industry and produces huge amounts of waste solids and liquid fractions which are a major source for composting of organic residues. Large amounts of greenhouse gases (carbon dioxide, nitrous oxide) and ammonia are released to the environment during the composting process and become a major concern for environmental health. The solid biowaste from cattle farms was inoculated with biochar and emissions of methane, carbon dioxide, nitrous oxide and ammonia were measured in comparison to control. Present study may develop a sustainable method in the composting process to reduce the greenhouse gas emissions and improve the environmental health for a better tomorrow.

Lupins (Lupinus spp.) are legumes with high relevance for the sustainability of agricultural systems as they improve the soil quality, namely, through the fixation of atmospheric nitrogen, and have good adaptability to different climates and soil conditions. Besides, they possess high nutritive value, especially due to the high protein content of the seeds. Nevertheless, the plants' productivity and metabolism can be influenced by the genotype, the edaphoclimatic conditions, and the sowing practices. In this work, the effect of edaphoclimatic conditions and sowing dates on the productivity, nutritional factors, and alkaloids of the seeds of L. albus cv. Estoril, L. angustifolius cv. Tango, and L. luteus cv. Cardiga was evaluated. High variability in the seeds and protein productions, nutritional traits, and alkaloid content related to the species was observed, along with a significant effect of the location. Lupinus albus cv. Estoril showed a good compromise between productivity and low alkaloid content, being an interesting genotype for food and feed use in the conditions of this trial.

Decomposition and litterfall are the primary mechanisms by which plants release their organic matter and nutrients into the soil, which helps prepare the stage for beneficial pathways in the restoration of damaged ecosystems. Species selection and allocation for the successful use of litter in ecological agricultural fields relies on knowing the mechanisms of plant litter decomposition and its influence on soil nutrients, which are crucial aspects of the ecosystem material cycle. In current study, In-vitro dry matter digestibility (IVDMD) used for evaluating quality animal feed reveals some potential in the decomposition of organic matter estimated. Nevertheless, some consensual advantages as laboratory incubation, this methodology demands a validation procedure. Therefore, the present work aimed to validate the IVDMD methodology by comparison with field buried litter bag mass loss, for 27 organic materials with different origins and chemical quality. The results reveal significant differences among the organic materials studied, reflecting their chemical quality variation, with digestibility values varying between 10.1 g kg-1 in composted sewage sludge and 982.0 g kg-1 in pig meat meal. IVDMD presented high accuracy results for all studied periods, with best results observed for 28 days incubation period (r2adj=0.959 ***). Taking the chemical fractions that participated in initial decomposition process the IVDMD is a potential indicator of a labile decomposable pool of organic materials. Considering the high accuracy, repeatability (CV=4.6%) and practicability, the IVDMD is a reliable alternative to the litter bag method in field mass loss availability.

Seasonal and daily variations of gaseous emissions from naturally ventilated dairy cattle barns are important figures for the establishment of effective and specific mitigation plans. The present study aimed to measure methane (CH4) and ammonia (NH3) emissions in three naturally ventilated dairy cattle barns covering the four seasons for two consecutive years. In each barn, air samples from five indoor locations were drawn by a multipoint sampler to a photoacoustic infrared multigas monitor, along with temperature and relative humidity. Milk production data were also recorded. Results showed seasonal differences for CH4 and NH3 emissions in the three barns with no clear trends within years. Globally, diel CH4 emissions increased in the daytime with high intra-hour variability. The average hourly CH4 emissions (g h-1 livestock unit- 1 (LU)) varied from 8.1 to 11.2 and 6.2 to 20.3 in the dairy barn 1, from 10.1 to 31.4 and 10.9 to 22.8 in the dairy barn 2, and from 1.5 to 8.2 and 13.1 to 22.1 in the dairy barn 3, respectively, in years 1 and 2. Diel NH3 emissions highly varied within hours and increased in the daytime. The average hourly NH3 emissions (g h-1 LU-1) varied from 0.78 to 1.56 and 0.50 to 1.38 in the dairy barn 1, from 1.04 to 3.40 and 0.93 to 1.98 in the dairy barn 2, and from 0.66 to 1.32 and 1.67 to 1.73 in the dairy barn 3, respectively, in years 1 and 2. Moreover, the emission factors of CH4 and NH3 were 309.5 and 30.6 (g day- 1 LU-1), respectively, for naturally ventilated dairy cattle barns. Overall, this study provided a detailed characterization of seasonal and daily gaseous emissions variations highlighting the need for future longitudinal emission studies and identifying an opportunity to better adequate the existing mitigation strategies according to season and daytime.

Greenhouse gas emissions from dairy production represent a major source of emissions especially in Western Europe where the sector has grown over the past decade. Different feeding strategies have evolved and there is a need to identify effective mitigation measures. Life cycle assessment (LCA) was used to examine carbon footprints (CFs) of milk production across 71 commercial dairy farms in Ireland, Northern Ireland, England, Spain (Galicia and Basque regions), Portugal and France based on monthly data collection over two years. Emissions up to the farm gate were calculated within a global boundary with both higher tier emission factors (HTEF) applicable in respective countries, and default emission factors (DEF). The global warming potential (GWP) used was the GWP100 metric, however results were also calculated using GWP20 for comparison. Functional units were: (i) one tonne fat and protein corrected milk (FPCM); (ii) 1 ha of on-farm agricultural area (FAA); (iii) 1 ha of global agricultural area (GAA). Farms were categorised based on the proportion of time that cows spent grazing. Mean CF per tonne FPCM (FPCM-CF) were 1,129, 1237 and 1519 kg CO2e for grazing (>220d grazing; n = 16), mixed (up to 219d grazing; n = 17) and housed farms (0d grazing; n = 38), respectively. housed had the widest range, from 884 to 2494 kg CO2e/tonne FPCM, and included the farm with the overall lowest FPCM-CF. Housed also had the highest mean CF per ha FAA: 44.1 tonne CO2e, followed by mixed (15.2 tonne) and grazing (11.6 tonne). CF (tonne CO2e) per ha GAA followed the same ranking: housed (15.1), mixed (9.8) and grazing (9.2). There was no difference in ranking of the feeding strategies using DEF in comparison with HTEF. A stepwise regression analysis identified feed efficiency and age at first calving as important factors in determining FPCM-CF for all farms. Furthermore, N surplus was important for grazing & mixed farms. The proportion of uncovered slurry storage, milk yield per cow and the amount of bought in concentrate per cow were important for housed farms. Wide variation in CFs implies considerable potential for lowering emissions per tonne FPCM and per ha FAA and GAA, but it is imperative that mitigation measures are tailored to feeding strategy.

The identification of crops that simultaneously contribute to the global protein supply and mitigate the effects of climate change is an urgent matter. Lupins are well adapted to nutrient-poor or contaminated soils, tolerate various abiotic stresses, and present relevant traits for acting as ecosystem engineers. Lupins are best studied for their seeds, but their full foraging potential needs further evaluation. This study evaluated the effects of location and sowing date on forage production, proximate composition, and the detailed mineral and alkaloid profiles of three species of Lupinus (L. albus cv. Estoril, L. angustifolius cv. Tango, and L. luteus cv. Cardiga). Sowing date and location and their interaction with the plant species significantly affected the vast majority of measured parameters, emphasizing the effects of climate and soil conditions on these crops. The relatively high crude protein and in vitro digestibility support the potential of the lupin species studied as sustainable forage protein sources in diets for ruminant animals. The content of individual essential macro and trace elements was below the maximum tolerable levels for cattle and sheep. Lupanine, smipine, and sparteine were the most abundant quinolizidine alkaloids in L. albus cv. Estoril, lupanine, and sparteine in L. angustifolius cv. Tango, and lupinine, gramine, ammodendrine, and sparteine in L. luteus cv. Cardiga. Based on the maximum tolerable levels of total quinolizidine alkaloid intake, the dietary inclusion of forages of L. albus cv. Estoril and L. angustifolius cv. Tango does not pose a risk to the animals, but the high alkaloid content of L. luteus cv. Cardiga may compromise its utilization at high levels in the diet. Overall, the results reveal a high potential for lupins as protein forage sources well adapted to temperate regions and soils with lower fertility, with a relevant impact on livestock sustainability in a climate change era.

Broiler farming is a significant source of gaseous emissions. The aim of this study was to assess the effects of different litter additives on the emission of NH3, N2O, CO2, and CH4 during broiler housing and subsequent manure storage. The gaseous emissions from the housing facilities were evaluated during one fattening cycle in environmentally controlled rooms with three different additives applied to the litter material (10% w/w aluminum sulphate or biochar and 2.50 mg m−2 urease inhibitor), as well as a control. A storage experiment was conducted under laboratory conditions for 90 days to evaluate the influence of these three additives on gaseous losses. During broiler housing, the results indicated that NH3 emissions were reduced significantly (40–60%) by litter additives, while global warming potential (GWP) emissions were reduced significantly (31%) by Alum. The addition of Biochar (a 58% reduction) had the same significant effect as Alum (a 60% reduction) to mitigate these losses. The re-application of Urease (a 41% reduction) may be required to reach an equal or higher reduction. During storage, NH3 and GWP emissions were not significantly affected by the litter additives. During broiler housing and subsequent manure storage, NH3 emissions were reduced significantly (22–41%) by litter additives, whereas GWP emissions did not decrease significantly. Globally, it can be concluded that Biochar appears to be a good alternative to Alum due to its equal effectiveness in mitigating NH3 losses, without increasing the GWP potential in the housing and avoiding pollution swapping.

Microbial water quality is a major concern in the world, since the ingestion of water contaminated with microorganisms poses risks to human and animal health. The aim of this study was to evaluate the microbiological quality of drinking water on dairy cattle farms. The study was carried out to determine the occurrence of coliforms and enterococcus species in drinking water samples obtained from selected dairy cattle farms located in four different areas of Portugal (north, central, south and islands). A questionnaire was used to collect relevant information regarding farmer demographics, characteristics of the cattle farms, as well as number of animals per herd, number of adult cows, production type, water source, use of disinfectants and pasture area. In this study, a convenience sample of 32 dairy cattle farms was subjected to screening for water quality. The numbers of animals in the study were 8086 cattle, with a mean herd size of 253, of which 51.7% were cows. Coliform and enterococcus bacterial species were identified by performing the membrane filtration method. The occurrence of poor water quality was recorded in 19 (59.4%) cattle farms. Isolated bacteria included Escherichia coli (20.0%), Enterococcus faecalis (25.0%), total coliforms (65.6%) and fecal coliforms (43.8%). Farms that did not routinely perform disinfection had the worst water quality (70.8%) when compared with farms that performed disinfection (25.0%) (p = 0.022). This research revealed the importance of screening the quality of drinking water on cattle farms, which could contribute to improved animal, human and environmental health in a One Heath approach.

Grasslands are key elements of the global agricultural system, covering around two-thirds of all agricultural areas and playing an important role in biodiversity conservation, food security, and balancing the carbon cycle. Climate change is a growing challenge for the agricultural sector and may threaten grasslands. To address these challenges, it is vital to conduct in-depth climate studies to understand the vulnerability of grasslands. In this study, machine learning was used to build an advanced model able to evaluate the future impact of climate change on grassland vigour. The objective was to identify the most vulnerable grassland areas, analyse the interaction between climate and grassland performance, and outline management strategies against the detrimental implications of climate change. A Random Forest (RF) regression was used to model the Normalised Difference Vegetation Index (NDVI) using the Standardised Precipitation-Evapotranspiration Index (SPEI). The model explained 76% of the NDVI variability. The foremost significant predictors of grassland vigour are the SPEI with temporal lags of 1, 4, and 12 months. These findings suggest that the vegetative status of grasslands exhibits high sensitivity to short-term drought while also being influenced by the memory of past climatic events over longer periods. Future projections indicate an overall reduction in grassland vigour, mostly in RCP8.5. The results indicate that negative effects will be more pronounced in mountainous regions, which currently host the most vigorous grasslands. Dry lowlands in the north should continue to have the lowest vigour in the future. A substantial reduction in vigour is expected in autumn, with an effect on grassland phenology. The development of grasslands in winter, favoured by increasing temperatures and precipitation, can advance the harvesting of grassland (cutting) and the grazing of livestock. To ensure that vigour is maintained in less favourable zones, adaptation measures will be needed, as well as more efficient management of highlands to provide an adequate level of production.