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Global increase in aquaculture production has created a need to reduce its environmental impacts. Nutrients could be recycled especially at land-based recirculating aquaculture systems (RAS) by cultivating green microalgae in aquaculture effluent. However, microalgae are difficult to harvest. As a multi-trophic solution, mussels could be used in harvesting microalgae. We tested three European freshwater mussels (duck mussel Anodonta anatina, swan mussel A. cygnea, and swollen river mussel Unio tumidus) for filtering two common green microalgae (Monoraphidium griffithii and Selenastrum sp.) grown in RAS effluent. Mussels decreased microalgal concentrations in the tanks 42–83% over three consecutive trials. Algal concentrations at the end of each trial were lowest for both microalgae in tanks containing Anodonta mussels. Clearance rates were higher for Anodonta mussels than for U. tumidus. Mussels biodeposited more microalgae to tank bottoms when M. griffithii was filtered. Ammonium concentration decreased or did not change in tanks with M. griffithii, but increased in tanks containing Selenastrum sp. These results suggest that of the tested species Anodonta mussels and M. griffithii show best potential for RAS effluent bioremediation application. We conclude that a co-culture of microalgae and unionid mussels could be used for recycling nutrients in aquaculture. [ABSTRACT FROM AUTHOR]

Termites—one of the most abundant animal groups in tropical ecosystems—are vital in nutrient recycling, contributing significantly to maintaining ecosystem functioning. However, how selective they are in their litter food choice, and whether they prefer nutritious or less nutritious litter substrates, are still important unresolved questions.Here, we test the effect of litter traits on the removal of litter by fungus‐growing termites, a dominant group of macrodetritivores in the Serengeti‐Mara ecosystem. We used metal‐mesh litterbags to measure the mass loss of stem and leaf litter from 23 grass species after an incubation period of 61 days.Sheeting—soil deposits indicating termite presence—strongly increased with tannin and phenolic compounds, especially in leaf litter (R2 = 0.54), where highly aromatic species like Cymbopogon caesius and Bothriochloa insculpta exhibited the highest sheeting rates. Litterbags with sheeting displayed 66% higher mass loss on average compared to those without. Once termites had selected the substrate, mass loss increased consistently irrespective of litter traits.Quantifying the combined effects of sheeting frequency and differential mass loss, we found that fungus‐growing termites predominantly increased the mass loss of high‐nutrient litter. This was mainly due to additional mass loss in leaf litter, not stem litter, with tannin concentration being the primary predictor of enhanced overall decomposition by termites. This suggests termites ameliorate the otherwise adverse influence of plant secondary compounds on litter decomposition.Synthesis: Our results support the idea that fungus‐growing termites are generalists, as termites collected organic substrates with varying quality. The strong effect of phenolic compounds on sheeting rate implies that secondary compounds play an important role in termite substrate selection. The selective removal of substrates high in secondary compounds suggests fungus‐growing termites lift important constraints to microbial breakdown, potentially enhancing ecosystem‐level carbon and nutrient recycling rates. Termites play crucial roles in recycling organic matter across tropical biomes and our study highlights that the role of secondary compounds in their selection and detection in decomposition studies needs more attention [ABSTRACT FROM AUTHOR]

Two experiments were conducted in a naturally lit research greenhouse to validate our modified strategy for delivering nutrients to sub-irrigated chrysanthemum plants. A split-plot design was used with four blocks arranged randomly, three nutrient rates as the main plot, and two contrasting cultivars as the subplot. The entire nutrient supply was removed at bud break and markedly reduced during vegetative growth, compared to common commercial fertilizer formulations, without adversely affecting tissue nutrient levels and plant/inflorescence quality, indicating that the plants were functioning in the low nutrient sufficiency zone. Specific nutrients (Nt) were more likely to exhibit improved uptake efficiency (shoot Nt content/Nt supply) than improved utilization efficiency (inflorescence DM/shoot Nt content) with decreasing nutrient supply. Thus, the common practice of delivering superfluous nutrient levels to greenhouse-grown chrysanthemum has little scientific merit in terms of nutrient accumulation and plant longevity. Applying a low‐input nutrient delivery strategy to the cultivation of indoor-grown, potted ornamental plants would improve the overall sustainability of the Canadian floricultural industry. [ABSTRACT FROM AUTHOR]

With increases in global population and urbanization, the production of Municipal Solid Waste (MSW) is growing rapidly, thus contributing to social and environmental concerns for sustainable waste management. This study addresses the research gap in optimizing composting, hypothesizing that integrating best practices and recent innovations can enhance the efficiency of the process. Data were collected through a systematic review of existing literature using Google Scholar and Scopus databases. The review provides an overview of municipal organic waste composting, outlining its processes, benefits, and challenges with the aim of identifying key area of further improvement and possibilities of adopting recent technological innovations. The analysis emphasized that technological advances in composting, as microbial inoculants or in-vessel composting have greatly improved the efficiency and quality of the resulting compost. However, several challenges remain, including managing contaminants such as heavy metals and microplastics, ensuring the compost quality and safety and addressing socioeconomic barriers that prevent widespread adoption. Moreover, process optimization, environmental and economic evaluation, as well as political and public involvement are essential to unlock the whole potential of composting systems. [ABSTRACT FROM AUTHOR]

The disposal of sewage sludge (SS) is an environmental issue in many large cities worldwide. Due to its high nutrients and organic matter contents, the SS can be used as a substrate to produce tree seedlings. However, few studies evaluate the suitability of SS from different wastewater treatment plants (WWTP) as seedlings' substrates. The present study assessed the chemical and physical properties of three SS from different WWTPs and two commercial substrates (CS), aiming to evaluate how the SSs' properties can affect the production of seedlings from two tree species. SS from Alegria, Ilha, and Sarapuí WWTP were assessed, and CS was composed mainly of peat and pine bark. As chemical properties, heavy metals, macro, and micronutrients total contents were evaluated. Meanwhile, density and porosity were measured as physical properties. The growth in shoot height was measured for seedlings of two Atlantic Forest species (Colubrina glandulosa and Peltophorum dubium). The SS showed higher nutrients (mainly N and P), and the CS had better physical properties. The Ilha and Sarapuí SS are recommended as substrates to produce seedlings of both species. Considering its low macroporosity, the Alegria SS must be mixed or composted with other materials to be used as a substrate for tree species. Although the contents of aluminum, zinc, and other metal were high in the SS, no adverse effects were observed in seedlings. Without chemical fertilizers, SS from Ilha and Sarapuí produced seedlings in a shorter period and with higher growth than those grown with CS plus chemical fertilizers. [ABSTRACT FROM AUTHOR]

• Cities benefit from nutrient circularity integrating waste and local agriculture. • Significant benefits from biogas generation and avoiding mixed waste treatment. • Nutrient concentrations in urban agricultural soils limit application of compost. • Local regulations and soil quality hinder nutrient circularity in urban areas. Cities face the challenges of supplying food and managing organic municipal solid waste (OMSW) sustainably amid increasing urbanization rates. Urban agriculture (UA) can help with this effort by producing local crops that are fertilized with nutrients recovered from compost generated from OMSW. This research aims to determine the potential of OMSW compost to supply the nitrogen-phosphorus-potassium (NPK) demand of UA and the environmental benefits of replacing mineral fertilizer from a life cycle perspective. The Metropolitan Area of Barcelona (AMB) serves as the case study given its commitment to reuse biowaste according to the Revised Waste Framework Directive and to promote UA as a signing member of the Milan Urban Food Policy Pact. Based on crop requirements and farmer surveys, we find that the annual NPK demands of the agricultural fields of the AMB that cover 5,500 ha and produce 70,000 tons of crops are approximately 769, 113, and 592 tons of NPK, respectively. Spatial material flow analysis and life cycle assessment were applied to found that the current waste management system can potentially substitute 8 % of the total NPK demanded by UA with compost, reduce the impacts by up to 39 % and yield savings in global warming of 130 %. The more ambitious future scenario of 2025 can potentially substitute 21 % of the total NPK demand and reduce environmental impacts up to 1,049 %, depending on the category considered. Avoiding processing of mixed OMSW, mineral fertilizer replacement and cogeneration of electricity from biogas are the major contributors to these environmental savings. [ABSTRACT FROM AUTHOR]

Applying sewage sludge and biosolids to agricultural lands has become an increasingly essential aspect of sustainable waste management and circular economy as it contributes positively to nutrient recycling, soil fertility and environmental health. Due to the widespread presence of per and polyfluoroalkyl substances (PFAS) globally, wastewater treatment plants have become a sink for PFAS. PFAS resist degradation by conventional wastewater treatment processes and are usually adsorbed to sewage sludge and biosolids. However, there have been significant concerns that land application of sewage sludge and biosolids could become a probable pathway for PFAS to enter the food chain. This article assessed the global sewage sludge/biosolids generation and country-to-country management methods through a systematic review. The global occurrence, distribution and prevalence of different classes of PFAS were assessed. We also evaluate the factors influencing PFAS contamination in sewage sludge/biosolids and the existing regulations on the upper limit of PFAS in biosolids before their disposal or application to farmland (or other usages). Additionally, most reports revealed high PFAS concentrations in influent, effluent, sewage sludge and biosolids generated worldwide. Overall, recorded PFAS concentration on a global scale varied from 2.2 to 2,156 ng/L (influents), 1.9-4,800 ng/L (effluents) and 2.1-500,000 ng/g (biosolids). While most studies focused on legacy PFAS detection, recent studies have revealed the prevalence of diPAPs in high concentrations in sewage sludge and biosolids, contributing from 40% to 95% of the total PFAS concentration. Across all PFAS classes, PFAAs and diPAPs were the dominant groups exhibiting elevated detection rates (35%-95%). Due to documented PFAS contamination in agricultural lands, rigorous regulations need to be instituted to govern the application of these biowastes on agricultural lands. However, several countries lack data on the level of PFAS in the sewage sludges they generate, and there are currently few or no regulations guiding their application to farmlands. Notably, the diPAPs class of PFAS was shown to be present in biosolids and sewage sludge; their inclusion in the list of PFAS required in standardized analytical methods and risk assessment becomes imperative. [ABSTRACT FROM AUTHOR]

• Field experiment in mandatory recycling scheme tests effectiveness of door stepping. • Majority of households in mandatory recycling schemes separates waste correctly. • Minority of households is responsible for most miss sorting. • Door stepping does not influence behavior of households in mandatory schemes. • Door stepping can improve recycling behavior in voluntary recycling schemes. Household organic waste has great potential for closing nutrient cycles in agriculture. This requires proper waste separation by households. Personal communication at the doorstep potentially improves household waste separation behaviour but it is expensive and findings from existing research are mixed. Based on results of previous studies and from a quasi-experiment with non-equivalent groups design in two German municipalities, this paper argues that efficiency of personal communication depends on its context. It can positively influence behaviour when recycling is voluntary and participation rates are low. However, it has no significant effects if recycling is mandatory. One explanation could be different perceptions of recycling in mandatory and voluntary schemes. In voluntary schemes door stepping can activate the intrinsic motivation of households. In mandatory schemes, all households need to participate irrespective of intrinsic motivation. This research shows that this creates a situation in which a small share of households is responsible for almost all contamination. This can be overcome by considering extrinsic factors that affect recycling behaviour. The paper recommends further research to understand which combination of incentives, sanctions and information is efficient in affecting behaviour change in mandatory recycling schemes. [ABSTRACT FROM AUTHOR]

We evaluated the operational, financial, and management challenges within China's Toilet Revolution by surveying 656 rural households across 10 provinces. The results revealed that the majority of households which renovated their toilets under the Toilet Revolution perceived positive impacts of this on their quality of life and living conditions. Households that had undertaken toilet renovations viewed the program more favorably than households which had not undertaken renovation, and were more willing to engage with the program. Despite the perceived benefits, households were generally hesitant to personally invest in toilet renovation. We uncovered a gap in strategic sanitation planning for post-construction operation and maintenance of toilets, reflecting a "build first, manage later" approach in the Toilet Revolution. We also identified a widespread lack of formal models for management of toilets and toilet products, coupled with high reliance among households on government support and subsidies to fund renovation. To address operational inefficiencies and financial sustainability issues in the program, we propose a novel "Toilet Business" model that leverages a sanitation value chain approach. In this model, private sector engagement, cost management, and market revitalization are crucial components that must be implemented to ensure the program's long-term success. Overall, our study provides valuable insights into the complexities of implementing large-scale sanitation programs such as the Toilet Revolution. [ABSTRACT FROM AUTHOR]

Recycling and reusing phosphorus in agriculture can reduce the consumption of natural phosphorus resources, which are continuing to shrink. Phosphorus fertilizers made from renewable raw materials (sewage sludge ash, animal bones, dried animal blood) and activated with phosphorus solubilizing microorganisms (Bacillus megaterium, Acidithiobacillus ferrooxidans) offer an alternative to conventional fertilizers. These products should meet consumer and environmental safety standards. In this paper, based on field experiments conducted in northeast Poland, the effects of waste-derived biofertilizers on selected parameters of wheat yield quality are discussed. The study focuses on the technological properties of the grain (hectoliter weight, hardness index, Zeleny index, starch, wet gluten, and protein content), the content of proteogenic amino acids, macro- and micronutrients, and selected toxic elements in the grain. The quality parameters of wheat grain were not affected by the tested biofertilizers applied in P doses up to 35.2 kg ha−1, nor by conventional fertilizers. [ABSTRACT FROM AUTHOR]

Purpose: As LCA is widely applied for benchmarking and decision-making, the need to clarify the ambiguity within fundamental methodological issues is imperative. Nutrient substitution, a subcategory of substitution, where credits are given for secondary fertilizer, is one of the common means to solve multi-functionality in LCA studies. This review aims to unravel the unique challenges associated with nutrient substitution, given the increasing relevance attributed to this topic. Methods: A systematic review of LCA studies available in Scopus and Web of Science (WoS) has been conducted. Studies about the recovery of nutrients from waste streams to produce fertilizer were scrutinized. As this review focuses on nutrient substitution methodology, only studies applying substitution for secondary fertilizer were included. PRISMA checklist has been used for reporting and completeness check of the review. Results are demonstrated from system modeling and explicit substitution procedure perspectives, supplemented by an investigation on sensitivity analysis. Results and discussion: As a general caveat, poor documentation and low transparency have been observed. Substitution has been used to model attributional (ALCA) and consequential LCA (CLCA) systems. The choice of functional unit combined with nutrient substitution in ALCA could attribute impacts to other functions than those studied. The determination of system boundary, especially the incorporation of the Use on Land (UoL) stage and avoided UoL emissions, is not always in accordance with the selected system modeling. Furthermore, there is no consensus on calculating the nutrient substitution rate. Single and aggregated factors comprising internal product quality, external-environmental, and external-societal variables have been identified. A prevalent observation among most studies is the absence of a sensitivity analysis pertaining to the nutrient substitution rate. Conclusion: The consistency of nutrient substitution cannot be achieved without an unambiguous definition and connotation of substitution and system modeling. The exclusion of the UoL phase not only limits the scope of a study but also fails to reflect quality differences between primary and secondary products. The key lies in elevating awareness regarding the intricacies of nutrient substitution, which consequently necessitates a rigorous definition and integration of influential factors when calculating substitutability. [ABSTRACT FROM AUTHOR]

Volcanic tuffs rich in chabazite zeolites have been extensively examined for their potential to enhance soil properties and increase fertilizer efficiency, both in their natural state and when enriched with nitrogen (N). However, there is a scarcity of data regarding their utilization in acidic sandy soil, particularly when used alongside organic fertilizers. This paper presents the findings of a 50-day laboratory incubation study that investigated the dynamics of N pools in an acidic sandy-loam agricultural soil treated with various N sources. These sources included urea, N-enriched chabazite zeolite tuff, and pelleted composted manure applied at a rate of 170 kg N/ha. Additionally, the N sources were tested in combination with chabazite zeolite tuff mixed into the soil to assess its role as a soil conditioner. The results revealed distinct behaviours among the tested N sources, primarily impacting soil pH and N dynamics. Soil fertilized with manure exhibited slow N mineralization, whereas N-enriched zeolite displayed a more balanced behaviour concerning net NO3−-N production and NH4+-N consumption. Both N-enriched zeolite and urea temporarily altered the soil pH, resembling a "liming" effect, while pelleted manure facilitated a prolonged shift towards neutral pH values. Considering the water adsorption capacity of zeolite minerals, caution is advised when adjusting water content and employing combustion methods to measure soil organic matter in zeolite-treated soil to avoid potential inaccuracies. In summary, N-enriched chabazite zeolite tuff emerged as a valuable N source in acidic sandy-loam soil, offering a promising alternative to synthetic fertilizers and showcasing a sustainable means of N recycling. [ABSTRACT FROM AUTHOR]

Growing algae on anaerobic digestate could decrease the algal production cost while reducing nutrient pollution. In past work, we developed a successful biological pretreatment for digestate that enables rapid algal growth on digestate without dilution. The objective of this work was to test the effectiveness of this pretreatment in outdoor algae cultures over a year-long timeframe. The study was conducted in semi-continuous, replicated bubble column photobioreactors in Auburn, AL, USA. Algae could grow successfully in pretreated digestate during the fall, spring, and summer, achieving average growth rates of 30, 42, and 66 mg L-1 d-1, respectively. Although the cold temperatures in winter suppressed algal growth, external heating was not required to keep the cultures alive. For two weeks during the summer, the system was challenged with 100% digestate that did not undergo pretreatment, and the algal community suffered a culture collapse with a significant (p < 0.001) decrease in productivity compared to the previous batches in which pretreatment was used. Nitrogen, phosphorus, and sulfur removal were observed during robust algal growth. There was no nitrification in the photobioreactors during the initial 200 days, but evidence of nitrification emerged during the summer and persisted into the fall. Nitrospirae were detected by 16S rRNA sequencing, proving that nitrifying bacteria could adapt to high ammonium (462 - 1502 mg/L). The eukaryotic community was dominated by Coelastrum (>90%) in the cold season, and the dominance transitioned to Chlorella in the warm season (>95%) based on 18S rRNA sequencing. The low relative abundance of cyanobacteria showed that green algae were the favored photosynthetic organisms in the system. [ABSTRACT FROM AUTHOR]

Sustainable management of lakes requires us to overcome ecological, economic, and social challenges. These challenges can be addressed by focusing on achieving ecological improvement within a multifaceted, co-beneficial context. In-lake restoration measures may promote more rapid ecosystem responses than is feasible with catchment measures alone, even if multiple interventions are needed. In particular, we identify restoration methods that support the overarching societal target of a circular economy through the use of nutrients, sediments, or biomass that are removed from a lake, in agriculture, as food, or for biogas production. In this emerging field of sustainable restoration techniques, we show examples, discuss benefits and pitfalls, and flag areas for further research and development. Each lake should be assessed individually to ensure that restoration approaches will effectively address lake-specific problems, do not harm the target lake or downstream ecosystems, are cost-effective, promote delivery of valuable ecosystem services, minimize conflicts in public interests, and eliminate the necessity for repeated interventions. Achieving optimal, sustainable results from lake restoration relies on multidisciplinary research and close interactions between environmental, social, political, and economic sectors. This article is categorized under: Science of Water > Water Quality Water and Life > Stresses and Pressures on Ecosystems Water and Life > Conservation, Management, and Awareness [ABSTRACT FROM AUTHOR]

Purpose: The increasing demand for fertilizers and their rising prices has led to the search for new nutrient sources, especially in rural areas where family farming predominates. In this study, we assessed the potential of reusing sediment deposited in surface reservoirs as a soil conditioner in a semiarid region, focusing on two features: the characterization of sediment physicochemical properties at the regional scale and the effect of the substrate containing sediment on the growth and physiology of maize. Methods: Sediment from the beds of 14 reservoirs was investigated, and two of them were used for the preparation of substrate for maize cultivation. Differences between the physicochemical properties of the sediments were analyzed using ANOVA and Tukey's test at a significance level of 0.05. The experimental design of the plant experiment was entirely randomized, in a factorial arrangement of two sources and four doses of sediment: 25, 50, 75, and 100% of the economic dose of 100 t ha−1 previously proposed in the study region. Two treatments were considered as controls: a substrate containing only soil and a treatment containing soil and chemical fertilizer. The data for each treatment were submitted independently considering the doses and sediment sources, and the means were compared by Tukey's test. Results: In general, nutrient contents were higher in the sediment of the surface reservoirs than in the soil. For instance, the concentrations of nitrogen and potassium were three to 10 times higher in the sediment, compared to the soil, and the organic matter content was up to six times higher. In the plant experiment, the dose and source of the sediments influenced all of the analyzed variables. The addition of sediments to the soil increased the chlorophyll content, photosynthesis rate, and growth of the leaves in relation to the treatment containing only soil. There were no significant differences between the biomass production and the plants' nutrient extraction with the largest dose of the most enriched sediment when compared to the treatment with chemical fertilizer. Conclusions: The experiment of maize plant growth showed the feasibility of using sediment deposited in reservoirs as a soil conditioner due to the enrichment of nutrients, organic matter, and fine particles. Therefore, sediment reuse has potential to improve livelihoods and food security, as well as contributing to a circular economy. However, prior analysis is required to avoid soil contamination and to set the most appropriate sediment dose, due to the high spatial variability of the sediment characteristics. [ABSTRACT FROM AUTHOR]

Native grasslands in the Pampas of South America are increasingly being replaced by Eucalyptus and Pinus stands. The short rotation regimes used for the stands require high nutrient levels, with litterfall being a major source of nutrient return. To model the litterfall production using climatic variables and assess the nutrient return in 14-year-old Eucalyptusgrandis and Pinustaeda stands, we measured litter production over 2 years, using conical litter traps, and monitored climatic variables. Mean temperature, accumulated precipitation, and mean maximum vapor pressure deficit at the seasonal level influenced litterfall production by E.grandis; seasonal accumulated precipitation and mean maximum temperature affected litterfall by P.taeda. The regression tree modeling based on these climatic variables had great accuracy and predictive power for E.grandis (N = 33; MAE (mean absolute error) = 0.65; RMSE (root mean square error) = 0.91; R2 = 0.71) and P.taeda (N = 108; MAE = 1.50; RMSE = 1.59; R2 = 0.72). The nutrient return followed a similar pattern to litterfall deposition, as well as the order of importance of macronutrients (E.grandis: Ca > N > K > Mg > P; P.taeda: N > Ca > K > Mg > P) and micronutrients (E.grandis and P.taeda: Mn > Fe > Zn > Cu) in both species. This study constitutes a first approximation of factors that affect litterfall and nutrient return in these systems. [ABSTRACT FROM AUTHOR]

Introduction: Production of strawberries in greenhouses and polytunnels is gaining popularity worldwide. This study investigated the effect of reuse of coir and peat, two substrates commonly adapted to soilless strawberry production, as well as stand-alone wood fiber from Norway spruce, a promising substrate candidate. Methods: The experiment was performed in a polytunnel at NIBIO Apelsvoll, Norway, and evaluated both virgin substrates, as well as spent materials that were used in one or two years. Yield, berry quality and plant architecture of the strawberry cultivar 'Malling Centenary' were registered. In addition, chemical and physical properties of virgin and reused substrates were investigated. Results: While plants grown in peat and wood fiber had highest yield in the first year of production, the berry yield was slightly reduced when these substrates were utilized for the second and third time. However, yield was comparable to the yield level attained in new and reused coir. Interestingly, berries grown in wood fiber had a tendency to a higher sugar accumulation. This substrate also produced the highest plants. Stand-alone wood fiber was the substrate with the highest accumulation of nitrogen during the three consecutive production cycles. All three investigated materials revealed a trend for decreased potassium accumulation. Wood fiber is characterized by the highest percentage of cellulose, however after three years of production the cellulose content was reducedto the same levels as for coir and peat. Discussion: Implementation of wood fiber as a growing medium, as well as general practice of substrate reuse can be therefore an achievable strategy for more sustainable berry production. [ABSTRACT FROM AUTHOR]

A new species of wood-soldier fly under the genus Solva Walker, 1859 (Diptera: Xylomyidae) (Solva andamanensis sp. n. Pramanik, Naskar & Banerjee) is described from the tropical forest of Andaman Island, India. Males can be distinguished from other species by a combination of characters, specifically the ochre yellow antenna; snow-white cylindrical palpi; yellow fore coxa, one antero-dorsal bristle in fore femur, black scutellum and black hind coxa. Male terminalia is illustrated here. Furthermore, Solva javana (Meijere, 1907) (Diptera: Xylomyidae) is reported for the first time from Andaman Island as well as India. The difference in habitus characters between these two species is also illustrated in this study. [ABSTRACT FROM AUTHOR]

A constant source of nutrient pollution that causes eutrophication is municipal wastewater treatment plant (WWTP) secondary effluent. This paper investigates the natural increase of pH, nutrient removal and biomass production from a cyclical re-cultivation system designed to favor the adaptation of microalgae consortia to WWTP secondary effluent. An outdoor experiment was performed with the microalgae consortia MC-10 under 3 sequential batch cycles. The natural pH increase (range 9-10) in the WWTP secondary effluent was established as an operation parameter because it certainly influenced microalgae biomass production (by maintenance and bioavailability of C and P), water treatment and pathogen removal. The increase of pH (9.7, 9.8 and 9.9) during the culture cycles of MC-10 probably generated conditions for fecal bacterial removal below detectable values (i.e., < 2 MPN/100 mL). The treatment of WWTP secondary effluent after batch cycles (cycles 1 to 3) using MC-10 indicated improvements in biomass productivity (66 to 167%) and a great potential for the reduction of total alkalinity (13.1 to 50.3%), NO3--N (30.9 to 53.6%), PO43- - P (90.4 to 93.0%) and electrical conductivity (EC) (8.5 to 18.1%). Additionally, the harvested biomass showed a high mineral concentration (46.5%) suggesting its potential use as a bio-fertilizer. [ABSTRACT FROM AUTHOR]

Applying sewage sludge and biosolids to agricultural lands has become an increasingly essential aspect of sustainable waste management and circular economy as it contributes positively to nutrient recycling, soil fertility and environmental health. Due to the widespread presence of per and poly-fluoroalkyl substances (PFAS) globally, wastewater treatment plants have become a sink for PFAS. PFAS resist degradation by conventional wastewater treatment processes and are usually adsorbed to sewage sludge and biosolids. However, there have been significant concerns that land application of sewage sludge and biosolids could become a probable pathway for PFAS to enter the food chain. This article assessed the global sewage sludge/biosolids generation and country-to-country management methods through a systematic review. The global occurrence, distribution and prevalence of different classes of PFAS were assessed. We also evaluate the factors influencing PFAS contamination in sewage sludge/biosolids and the existing regulations on the upper limit of PFAS in biosolids before their disposal or application to farmland (or other usages). Additionally, most reports revealed high PFAS concentrations in influent, effluent, sewage sludge and biosolids generated worldwide. Overall, recorded PFAS concentration on a global scale varied from 2.2 to 2,156 ng/L (influents), 1.9–4,800 ng/L (effluents) and 2.1–500,000 ng/g (biosolids). While most studies focused on legacy PFAS detection, recent studies have revealed the prevalence of diPAPs in high concentrations in sewage sludge and biosolids, contributing from 40% to 95% of the total PFAS concentration. Across all PFAS classes, PFAAs and diPAPs were the dominant groups exhibiting elevated detection rates (35%–95%). Due to documented PFAS contamination in agricultural lands, rigorous regulations need to be instituted to govern the application of these biowastes on agricultural lands. However, several countries lack data on the level of PFAS in the sewage sludges they generate, and there are currently few or no regulations guiding their application to farmlands. Notably, the diPAPs class of PFAS was shown to be present in biosolids and sewage sludge; their inclusion in the list of PFAS required in standardized analytical methods and risk assessment becomes imperative.

Microalgae biotechnology can strengthen circular economy concepts in the wastewater treatment sector. This study investigated the Norwegian microalgae strains of Tetradesmus wisconsinensis, Lobochlamys segnis, and Klebsormidium flaccidum for their efficiency in nutrient removal. Their biomass productivity and compositions were evaluated for bioenergy and bi-products development. In the laboratory batch experiment with synthetic municipal wastewater, all strains accomplished total removal of nitrogen and phosphorus. L. segnis removed all NH4+ and PO43− (initial concentration of 28 and 15 mg/L, respectively) earliest among others. T. wisconsinensis biomass was superior in total carbohydrates content (40%) and fatty acid profile that imply biorefinery potential. The fatty acid (TFA) content was the highest in L. segnis (193 ± 12 mg/g dry cells), while K. flaccidum accumulated fatty acids that consisted largely of polyunsaturated fatty acids (82% of TFA). The highest protein level was measured in K. flaccidum (53%). Observed variations in biomass components can be used for a strategic production of targeted compound in resource recovery scenarios for biofuel generation. [ABSTRACT FROM AUTHOR]

Zoo waste is a common problem in urban areas, as it overloads municipalities. To enhance the park's appeal, sustainability, and cleanliness, a pilot vermicomposting process was implemented as an alternative for organic waste disposal. It aimed to address the negative effects of poor organic waste management. Three types of pond water, namely hippopotamus, crocodile, and gharial, were recycled. Additionally, ostrich droppings and the nitrogenous compounds abundant in carnivore feces were utilized. The study sought to improve organic waste management and recycle pond water using exotic worms. Chemical and physical analyses were conducted on pond water and vermicompost obtained from Gandhi Zoological Park, revealing their high nutrient content. Fourier transform infrared spectroscopy was employed to study the functional groups present in the compost and vermicompost, allowing the detection of vermicompost maturity. The biomass of exotic earthworms, as well as the count of cocoons, juveniles, and adults, was assessed during different seasons of the year. This approach facilitated the recycling of pond water and the reduction of organic waste within the zoo premises. It involved the symbiotic cooperation of earthworms and bacterial colonies, transforming the waste into a high‐quality product with balanced macro nutrients. The novelty of the study lies in its focus on nutrient recycling in pond water, ostrich droppings, and vermicomposting of organic waste from carnivores. [ABSTRACT FROM AUTHOR]

Animal excretion provides nutrients for primary productivity and can be a crucial component of ecosystem nutrient cycling. The concentrations of carbon (C), nitrogen (N), and phosphorus (P) in an animal's excretion are strongly influenced by the C:N:P stoichiometry (molar ratios) of its body and of the food it eats. We measured the C:N:P ratios of quagga mussel (Dreissena rostriformis bugensis) tissues and excreta and of seston across wide environmental and spatial gradients in the upper Laurentian Great Lakes. We then investigated how mussel excretion rates were impacted by stoichiometric mismatch—the difference between the C:P ratios of mussel tissues and the C:P ratios their food. Quagga mussel internal C:N:P stoichiometry varied significantly across sites and seasons, driven primarily by changes in tissue P concentrations. When mussel tissues had substantially lower C:P ratios than seston (that is, strong stoichiometric mismatch), mussels excreted significantly less N and P relative to C. Excretion C:N ratios varied by nearly threefold, while C:P ratios varied by tenfold. The effect of the stoichiometric mismatch on excretion stoichiometry was more dramatic in the spring, when mussels had higher tissue P concentrations, than in the summer. This suggests seasonality in mussel P demand. Our results challenge the assumption of strict internal homeostasis in consumers and demonstrate that food and tissue stoichiometry need to be considered to predict consumer excretion stoichiometry. These findings help to better understand the impact of consumer-driven nutrient cycling in aquatic environments and quagga mussel contributions to the nutrient budgets of invaded ecosystems. [ABSTRACT FROM AUTHOR]

Human urine contains nutrients that are mainly not recycled in agriculture. It can be collected through source separation and treated to produce "urine-based fertilizers" with various nutrient contents and physiochemical characteristics. We measured ammonia (NH3) volatilization after the application of several urine-based fertilizers under controlled conditions and of stored urine under field conditions. The nitrogen-use efficiency of four urine-based fertilizers (stored urine from a university, stored urine from a festival, fermented urine and nitrified concentrated urine) was compared under on-farm conditions with ammonium nitrate and bovine slurry in a specific experiment. Stored urine was also compared with ammonium nitrate and seven other organic fertilizers in different experiments under on-farm conditions. Nitrous oxide emissions after the application of two urine-based fertilizers were also measured. NH3 volatilization from stored urine was high (up to 34% of the total nitrogen under on-farm conditions) compared with the other urine-based fertilizers and ammonium nitrate. Urine-based fertilizers were characterized by a nitrogen fertilizer replacement value (NFRV) greater than 70% and higher than that of all other organic fertilizers used in the experiments (but not significantly different). These differences were mainly explained by the mineral nitrogen content of the fertilizers. The mean NFRV of stored urine over five experiments was 83% (significantly lower than 100%). Nitrous oxide emissions from stored urine, nitrified concentrated urine and ammonium nitrate were low. We concluded that urine-based fertilizers could replace mineral fertilizers if NH3 volatilization is limited. The constraints linked to the field application of a large volume call for further investigation. [ABSTRACT FROM AUTHOR]

Background: Wastewater from sewage treatment plants contains high levels of nutrients, which can be used for plant nutrition. Classical wastewater treatment plants use complex microbial consortia of autotrophic and heterotrophic microorganisms for biological wastewater treatment. Certain autotrophic microalgae (e.g., species of the genera Chlorella, Scenedesmus, and Pediastrum) accumulate nutrients from wastewater very effectively. Aims: We investigated the potential of microalgae biomass obtained from a prototype wastewater treatment plant as a source of nutrients for crops, focusing on nitrogen. Methods: We provided wheat plants with different levels of algae biomass equivalent to 60, 120, and 180 kg N per hectare or with mineral fertilizer (N, P, and K) equivalent to the amounts contained in the algal biomass. Physiological and phenotypic traits were measured during growth, including vegetation indices, photosynthetic performance, growth, and nitrogen use efficiency (NUE). In addition, the adundances of Bacteria, Archaea and fungi and genes of ammonium oxidizing Bacteria and Archaea were determined in the rhizosphere of differently fertilized plants. Results: Microalgal application at fertilizer levels of 120 and 180 kg N ha–1 showed significantly improved physiological performance, growth, yield and nutrient uptake compared to the unfertilized control. Nevertheless, their yields and NUE were lower than with the application of equal amounts of mineral fertilization, while the adundance of rhizosphere microbes and ammonia‐oxidizing microorganisms were not significantly affected. Conclusions: Microalgae from wastewater treatments form a suitable source of organic fertilizer for wheat plants with only moderate reductions in N use efficiency compared to mineral fertilizer. [ABSTRACT FROM AUTHOR]

Recycling resources excreted in human urine can help achieve a sustainable future and circular economy in the sanitation space. However, many studies researching different technologies for safely recycling urine do not use real human urine for experimentation, relying instead on recipes for making synthetic or artificial solutions that attempt to mimic the composition of real human urine. This methodological choice is the focus of this article, which points out that the real urine matrix is extremely complex, with a metabolome (>2,500 metabolites) that differs greatly from that of synthetic urine (

Agricultural crop residues include leftover and unmarketable materials, such as crop stover, weeds, leaf litter, sawdust, forest litter, and livestock manure originating from crop cultivation, and post-harvest activities. Such residues are a storehouse of plant nutrients and several other resources and therefore need to be managed in an environment- friendly manner with minimum loss of plant nutrients and other resources that can be recovered. Microbial starter consortia are a key component in the rapid recycling of farm residue wastes and the production of other valuable products, such as biogas, bioethanol/biofuel, enzymes, molecules, and metabolites. Recent advances in microbial biotechnology can also facilitate the conversion of farm residues into economically valuable materials, i.e. soil additives, adsorbents, energy, and enzymes, thereby contributing to a circular economy. This special issue attempts to compile the latest advancements in the field of agricultural crop residue management for enhanced nutrient recycling and resource recovery by the use of compost starters and inoculant formulations.

Nutrient availability plays a crucial role in microalgae growth in domestic wastewater. In this study, we investigated the impact of different nitrogen and phosphorus ratios (5:1, 10:1, and 20:1, m∙m−1), and the addition of inorganic carbon on microalgae growth and nutrient uptake from domestic wastewater. Microalgae biomass achieved values ranging from 0.54 to 1.41 g·L−1. The cultivation process had maximum removal efficiencies of 83.7% for soluble chemical oxygen demand (sCOD), 74.0% for total Kjeldahl nitrogen (TKN), and 100.0% for ammonia (NH3) and orthophosphate (PO43−). All the NH3 and PO43− concentrations from domestic wastewater without supplementation were completely removed on the fourth day of cultivation. Moreover, no significant differences in microalgae growth, and NH3 and PO43− removals were observed between the conditions with and without nutrient supplementation on the fourth day of cultivation. This study has shown the feasibility of growing microalgae in domestic wastewater without any nutritional supplementation. Further investigations are required to check the long-term performance, energy requirements, and economic viability of this system for wastewater treatment and the production of nutrient-rich biomass for agricultural applications.

Recycling and reusing phosphorus in agriculture can reduce the consumption of natural phosphorus resources, which are continuing to shrink. Phosphorus fertilizers made from renewable raw materials (sewage sludge ash, animal bones, dried animal blood) and activated with phosphorus solubilizing microorganisms (Bacillus megaterium, Acidithiobacillus ferrooxidans) offer an alternative to conventional fertilizers. These products should meet consumer and environmental safety standards. In this paper, based on field experiments conducted in northeast Poland, the effects of waste-derived biofertilizers on selected parameters of wheat yield quality are discussed. The study focuses on the technological properties of the grain (hectoliter weight, hardness index, Zeleny index, starch, wet gluten, and protein content), the content of proteogenic amino acids, macro- and micronutrients, and selected toxic elements in the grain. The quality parameters of wheat grain were not affected by the tested biofertilizers applied in P doses up to 35.2 kg ha−1, nor by conventional fertilizers.

Societies have always been occupied with securing food supply and ensure environmental and human health. Scientific knowledge and technical level have, together with habitat and management patterns, shaped sanitation arrangements and recycling of resources. Because it is the same urban problems that are addressed by societies in different historical contexts, a longitudinal study may allow for novel ways to conjure food security and sanitation management issues in the present century.We trace the historical transition over two centuries away from a circular economy to a more linear one in two Swedish cities, the capital Stockholm and the industrial city Norrköping, and show that big but rather slow changes occurred more or less constantly in these two urban settings. The driving forces have changed from only improving local conditions of sanitation and food production over to global and regional driving forces in this century affecting what local communities can or could do. The ongoing globalization positions the subjects of environmental and human health, recycling and food security in a new global perspective, where climate change and global resource boundaries will play a central role. We cannot continue to rely on trade that causes rainforest destruction elsewhere or harmful chemical consumer products that lead to loss of biodiversity and human health risks.We need to put urban sanitation and food issues into this wider perspective with available remedial measures such as dietary changes, food waste reduction, soil less food production and building of new circular infrastructure. All urban areas in the world, including Stockholm and Norrköping in Sweden, need to adopt new strategies that again engage residents as well as public sectors and industry, including agriculture.

Nutrient availability plays a crucial role in microalgae growth in domestic wastewater. In this study, we investigated the impact of different nitrogen and phosphorus ratios (5:1, 10:1, and 20:1, m∙m−1), and the addition of inorganic carbon on microalgae growth and nutrient uptake from domestic wastewater. Microalgae biomass achieved values ranging from 0.54 to 1.41 g·L−1. The cultivation process had maximum removal efficiencies of 83.7% for soluble chemical oxygen demand (sCOD), 74.0% for total Kjeldahl nitrogen (TKN), and 100.0% for ammonia (NH3) and orthophosphate (PO43−). All the NH3 and PO43− concentrations from domestic wastewater without supplementation were completely removed on the fourth day of cultivation. Moreover, no significant differences in microalgae growth, and NH3 and PO43− removals were observed between the conditions with and without nutrient supplementation on the fourth day of cultivation. This study has shown the feasibility of growing microalgae in domestic wastewater without any nutritional supplementation. Further investigations are required to check the long-term performance, energy requirements, and economic viability of this system for wastewater treatment and the production of nutrient-rich biomass for agricultural applications. [ABSTRACT FROM AUTHOR]

Incorporating a variety of microalgae into wastewater treatment is considered an economically viable and environmentally sound strategy. The present work assessed the growth characteristics of Chlorella sorokiniana during cultivation in balanced synthetic media and domestic wastewater. Increasing the NH4+–N concentration to 360 mg L−1 and adding extra PO43−–P and SO42−–S (up to 80 and 36 mg L−1, respectively) contributed to an increase in the total biomass levels (5.7–5.9 g L−1) during the cultivation of C. sorokiniana in synthetic media. Under these conditions, the maximum concentrations of chlorophylls and carotenoids were 180 ± 7.5 and 26 ± 1.4 mg L−1, respectively. Furthermore, when studying three types of domestic wastewaters, it was noted that only one wastewater contributed to the productive growth of C. sorokiniana, but all wastewaters stimulated an increased accumulation of protein. Finally, the alga, when growing in optimal unsterilized wastewater, showed a maximum specific growth rate of 0.73 day−1, a biomass productivity of 0.21 g L−1 day−1, and 100% NH4+–N removal. These results demonstrate that the tested alga actively adapts to changes in the composition of the growth medium and accumulates high levels of protein in systems with poor-quality water. [ABSTRACT FROM AUTHOR]

Proper management of livestock invariably includes sustainable methods of reusing their manure. Considering the global scenario of animal manure handling and the need for sustained agricultural production, there is clear lack of a focused approach in achieving the environmental and economical resilience in small-scale farms. Present study reviews the possibility of employing co-composting as a suitable technology for safe and effective handling of animal manure along with other wasted materials of organic nature. The review identifies the scope of effective co-composting using different mixtures of manure, greens and bulking agents to achieve required stability and nutrient content of the product. The study highlights the state of the art in terms of (i) carbon and nitrogen transformation after composting, (ii) challenges in preparing ambient conditions, and (iii) feedstock selection to optimize the mix proportions. The study also highlights the challenges in preparation and application as well as the risks involved in handling emerging contaminants (toxins) such as hormones and antibiotics in manure in producing good quality compost, thereby breaking the chain of their reentry to the food cycles. The results of the study would impart sound technological interventions required to make the best use of animal manure compost in low fertile soils. [ABSTRACT FROM AUTHOR]

National policy styles and path-dependencies are affecting the abilities of Baltic Sea countries to deliver on their commitments under the Helsinki Convention. This article synthesizes evidence and insights from studies relating to the provisions on agricultural nutrient management, a main source of marine pollution. We contend that governments that are strongly concentrated vertically, while fragmented horizontally, lack capacity including with respect to informal institutions that can leverage implementation. As a stocktaking of institutional impediments to sustainable development, our analysis has wider relevance for other international agreements with Baltic Sea countries involved. [ABSTRACT FROM AUTHOR]

The exchange of material and individuals between neighboring food webs is ubiquitous and affects ecosystem functioning. Here, we explore animal foraging movement between adjacent, heterogeneous habitats and its effect on a suite of interconnected ecosystem functions. Combining dynamic food web models with nutrient‐recycling models, we study foraging across habitats that differ in fertility and plant diversity. We found that net foraging movement flowed from high to low fertility or high to low diversity and boosted stocks and flows across the whole loop of ecosystem functions, including biomass, detritus, and nutrients, in the recipient habitat. Contrary to common assumptions, however, the largest flows were often between the highest and intermediate fertility habitats rather than highest and lowest. The effect of consumer influx on ecosystem functions was similar to the effect of increasing fertility. Unlike fertility, however, consumer influx caused a shift toward highly predator‐dominated biomass distributions, especially in habitats that were unable to support predators in the absence of consumer foraging. This shift resulted from both direct and indirect effects propagated through the interconnected ecosystem functions. Only by considering both stocks and fluxes across the whole loop of ecosystem functions do we uncover the mechanisms driving our results. In conclusion, the outcome of animal foraging movements will differ from that of dispersal and diffusion. Together we show how considering active types of animal movement and the interconnectedness of ecosystem functions can aid our understanding of the patchy landscapes of the Anthropocene. [ABSTRACT FROM AUTHOR]

Decomposition is a major contributor to ecosystem respiration, determining the carbon emission and nutrient cycling rates. Our current understanding of decomposition dynamics and their underlying drivers has mainly focused on surface habitats but largely ignored in subterranean environments. Here we studied abiotic and microbial drivers of early-stage litter decomposition inside and outside caves along an elevational gradient in Tenerife. We found comparable decomposition rates (k) and litter stabilizing factors (S), with contrasting drivers and elevational variation. At the surface, we observed a mid-elevational trend in k, which tended to correlate with water availability, cooler temperatures, nutrient availability, and surface-specific bacterial taxa. In sharp contrast, caves showed no elevational impact nor influence of abiotic parameters and bacterial communities on k. Despite this, we found higher levels of S in caves, which were associated mainly with reduced water availability, lower temperatures and cave-specific bacterial taxa, indicating that conditions in caves are strongly linked with carbon storage. Our findings imply that our current perception of terrestrial habitat-based carbon cycling are underestimating the net carbon budget in areas with caves. Disentangling the role of the environment on decomposition in caves is key to fully characterize their roles in nutrient cycling and to understand how increasing anthropogenic pressures will affect fundamental processes in subterranean ecosystems.

Microgreens are emerging specialty crops becoming increasingly popular for their rich nutrient profile and variety of colors, flavors, and textures. The growing medium is a significant key factor in microgreen yield, quality, and sustainability. The widespread use of peat-based media raises questions regarding the environmental sustainability of microgreens production, and new substrates that are more sustainable are required. To this purpose, a study was designed with the objective of comparing eight alternative growing media evaluating their physicochemical properties and effect on yield, mineral profile, and nutritional quality of peas and radish microgreens. Tested substrates included a standard peat and perlite mixture (PP), coconut coir (CC), spent mushroom compost (SMC), organic waste compost (CMP), and 50:50 (v:v) mixes of PP and SMC, PP and CMP, CC and SMC, and CC and CMP. The physicochemical properties widely differed among the alternative substrates tested. SMC had high electrical conductivity and salt concentration, which resulted in poor seed germination. Growing media tested significantly influenced the production and nutritional quality of both microgreen species and variations were modulated by the species. With a 39.8% fresh yield increase or a small yield decrease (-14.9%) in radish and peas, respectively, PP+CMP (50:50, v/v) mix provided microgreens of similar or higher nutritional quality than PP, suggesting the potential of substituting at least in part peat with CMP. Using locally available CMP in mix with PP could reduce the microgreens industry reliance on peat while reducing costs and improving the sustainability of the production of microgreens. Further research is needed to evaluate also the potential economic and environmental benefits of using locally available organic materials like CMP as alternative growing media and peat-substitute to produce microgreens. [ABSTRACT FROM AUTHOR]

Maize is one of the most important cereals in the world. It is a crop demanding in nitrogen. Therefore, alternative sources of fertilization bring agronomic, environmental and economic benefits. The objective of this study was to evaluate the biomass and productivity of maize fertigated with wastewater from swine and fish farming in different dilutions. The soil used is classified as Dystroferric Red Latosol, Cerrado phase, with clayey texture. The experimental design used was randomized blocks in 2 × 4 split plots with three replications. The treatments consisted of two sources of wastewater (fish farming and swine farming) diluted with the recommended dose of wastewater + 0, 25, 50 and 75% of its volume in water. The accumulation of dry mass (leaf, stalk and aerial parts) was evaluated at 30, 60, 90 and 110 days after sowing. The evaluation of yield variables (number of grain rows, number of grains per row, grain sizes, grain dry weight, gran yield and harvest index) occurred at 130 days after sowing. The largest accumulation of dry biomass at the end of the maize cycle and evaluated productivity variables were obtained with the application of swine farming wastewater. Wastewater from fish farming applied via an irrigation system without dilution (0%) is the most suitable for obtaining the productivity of corn grains. The two sources of wastewater have the potential to partially replace mineral nitrogen fertilizer in maize. [ABSTRACT FROM AUTHOR]

Two nutrient–phytoplankton–zooplankton (NZP) models for a closed ecosystem that incorporates a delay in nutrient recycling, obtained using the gamma distribution function with one or two degrees of freedom, are analysed. The models are described by systems of ordinary differential equations of four and five dimensions. The purpose of this study is to investigate how the mean delay of the distribution and the total nutrients affect the stability of the equilibrium solutions. Local stability theory and bifurcation theory are used to determine the long-time dynamics of the models. It is found that both models exhibit comparable qualitative dynamics. There are a maximum of three equilibrium points in each of the two models, and at most one of them is locally asymptotically stable. The change of stability from one equilibrium to another takes place through a transcritical bifurcation. In some hypotheses on the functional response, the nutrient–phytoplankton–zooplankton equilibrium loses stability via a supercritical Hopf bifurcation, causing the apparition of a stable limit cycle. The way in which the results are consistent with prior research and how they extend them is discussed. Finally, various application-related consequences of the results of the theoretical study are deduced. [ABSTRACT FROM AUTHOR]

A total of twenty mixtures of weed, B-Lac and molasses were prepared in order to evaluate an accelerated liquid fertilizer (ALF) based on these plants. A mixture of 85% weed: water (1:1), 10% molasses and 5% BLac showed the best characteristics and was reproduced at a pilot scale. ALF was applied to lettuce using the following treatments: one foliar application per week of 10 mL L-1 (FA1), two foliar applications per week of 10 mL L-1 (FA2), one drench application of 50 mL L-1 every week (DA1), a drench application of 50 mL L-1 every two weeks (DA2) and a control without application (CWA). The variables evaluated were total yield, commercial yield, fresh weight, height, head diameter, percentage of dry matter and the concentration of foliar nitrogen, phosphorus, and potassium. The mixtures in the laboratory and pilot phase were evaluated in a completely randomized design. The field phase was assessed in a completely randomized block design with five treatments and four replications. No significant differences were found between the treatments, except in the percentage of dry matter and potassium content, where FA2 showed the best results (2.35% and 541 mg plant-1, respectively). The highest total yield (26.4 t ha-1) and commercial (24.11 t ha-1) were achieved with DA2; however, the nutritional content was lower than that in the other treatments. Using homolactic fermentation it was possible to recycle weeds and produce ALF, which has potential as a biofertilizer according to its chemical characterization and effects shown on lettuce cultivation. [ABSTRACT FROM AUTHOR]

Purpose: Sediment internal nutrient loading plays an important role in algal blooms. Thus, understanding the specific characteristics of nutrient (nitrogen (N) and phosphorus (P)) recycling from sediment is important for clarifying the processes and mechanisms of cyanobacterial growth and succession. Materials and methods: Sediments and water samples were collected monthly from five sampling sites in Lake Chaohu for 1 year. N and P concentrations in surface and interstitial water were determined, and fractions of sediment organic matter, P, and iron were quantified. P adsorption characteristics were modeled with adsorption isotherms. Results and discussion: Dolichospermum was the dominant bloom species in the western lake in April, followed by Microcystis from May to September in the whole lake. The impulsive regeneration and release mode from iron-bound P and ammonium (NH4+-N) regeneration from sediment in spring triggered the Dolichospermum bloom. In early summer, continuous P release potential as well as nitrate accumulation and NH4+-N deficiency due to NH4+-N prior assimilation by Dolichospermum jointly drove the transition from Dolichospermum to Microcystis due to the energy saving and competitive advantage of rapid uptake and storage of inorganic P as well as a wide range of N utilization forms for Microcystis. All these facts put the Dolichospermum towards common N and P stress. Furthermore, in summer, NH4+-N rapid regeneration from organic algal detritus remineralization due to the decline of Dolichospermum developed Microcystis blooms. Conclusions: The specific mode and pathway of N and P recycling from sediment determined the dominant algal species based on the particular N and P utilization strategies of the algae. Pulsed and a vast amount of P release facilitated the Dolichospermum growth, while continuous and a small quantity of P release was in favor of Microcystis growth. Organic N hydrolysis from Dolichospermum detritus further supported the development of a Microcystis bloom. [ABSTRACT FROM AUTHOR]

Volcanic tuffs rich in chabazite zeolites have been extensively examined for their potential to enhance soil properties and increase fertilizer efficiency, both in their natural state and when enriched with nitrogen (N). However, there is a scarcity of data regarding their utilization in acidic sandy soil, particularly when used alongside organic fertilizers. This paper presents the findings of a 50-day laboratory incubation study that investigated the dynamics of N pools in an acidic sandy-loam agricultural soil treated with various N sources. These sources included urea, N-enriched chabazite zeolite tuff, and pelleted composted manure applied at a rate of 170 kg N/ha. Additionally, the N sources were tested in combination with chabazite zeolite tuff mixed into the soil to assess its role as a soil conditioner. The results revealed distinct behaviours among the tested N sources, primarily impacting soil pH and N dynamics. Soil fertilized with manure exhibited slow N mineralization, whereas N-enriched zeolite displayed a more balanced behaviour concerning net NO3−-N production and NH4+-N consumption. Both N-enriched zeolite and urea temporarily altered the soil pH, resembling a “liming” effect, while pelleted manure facilitated a prolonged shift towards neutral pH values. Considering the water adsorption capacity of zeolite minerals, caution is advised when adjusting water content and employing combustion methods to measure soil organic matter in zeolite-treated soil to avoid potential inaccuracies. In summary, N-enriched chabazite zeolite tuff emerged as a valuable N source in acidic sandy-loam soil, offering a promising alternative to synthetic fertilizers and showcasing a sustainable means of N recycling.

Soil function encompasses numerous functions and services the soil provides and can be measured using physical, chemical, and biological characteristics. In any event, research on fertility and biological activity is increasingly being stressed as indices of ecosystem services. Rangeland degradation is one of the world's most widespread land use changes, with serious consequences for soil processes and ecosystem services. The influence of uncontrolled grass cover on soil functioning in semiarid environments is little understood. In the current study, the following seven varieties of grass coverings were studied in a semiarid area of central India: Cenchrus ciliaris (CC), Megathyrsus maximus (MM), Chrysopogon fulvus (CF), Heteropogon contortus (HC), Sehima nervosum (SN), Vetiveria zizanioides (VZ), and Tri-Specific Hybrid (TSH). The carbon accumulation proficiency of TSH, MM, and HC was ~2.23, 2.17, and 2.07 times greater than fallow. The nutrient cycling capacity of grasses was ~1.1 to 1.6 times greater than that of fallow, despite the grasses' depleted macronutrients in the soil. The biological activity under MM and HC was ~1.23 and 1.67 times higher than fallow. Overall soil functionality under TSH and HC was 83 and 25% greater than MM, respectively. These soil functions augment ecosystem services like climate regulation, biomass production, nutrient recycling, water, and airflow. However, more attention should be paid to the management of inputs for greater ecosystem services from this grass cover in semiarid, degraded land.

Human excreta can be used as biofertilizers due to their nutrient and organic matter content. Nevertheless, the behavior of microorganisms should be investigated, as enteric pathogens can accumulate in the soil. Therefore, we evaluated the survival and transport of two enteric bacteria (E. coli and Salmonella enterica) and two enteric virus surrogates (MS2 and ΦX-174 bacteriophages) when applied as contaminants of four biofertilizers on Lactuca sativa production. The study was carried out in lysimeters outdoors with repacked silt loam soil, using a randomized block design (RBD) with six treatments and three replicates. Biofertilizers were urea-treated feces, feces composted with organic waste, stored liquid urine, and struvite and were inoculated at 106–107 cfu/pfu g−1 of E. coli and bacteriophages strains and 107–109 of S. enterica. Soil amended with composted feces exhibited the lowest decimal reductions (T90) for the microorganisms evaluated, with 10.2 days for E. coli, 11.9 days for S. enterica, 22.2 days for MS2, and 3.7 days for ΦX-174. Urea-treated feces temporarily hindered the growth and survival of E. coli and S. enterica in the soil. However, both bacteria were present after one month, while MS2 showed a stable concentration with this biofertilizer. E. coli presented a stable behavior when applied with urine, whereas MS2 was stable with urea-treated feces, urine, and struvite. ΦX-174 and S. enterica were not considered good representatives of most resistant enteric pathogens’ behavior in the soil during food production since they were not detected in leachate and showed a rapid die-off in soil. E. coli leached faster and in higher concentrations than MS2, which presented higher concentrations in deeper soil layers, from 10 to 20 cm. Therefore, using urine, struvite, and urea-treated faces implied a higher chance of infection, as a decimal reduction time was not observed during the 36 days of the experiment. As a result, in short-term cultures, it is recommended that additional hygiene barriers are taken to avoid infection since E. coli and MS2 were still detected at the end of the experiment. An interval of 90 days between fertilizing and harvesting is recommended to prevent pathogen infection. These results are the basis for a quantitative risk assessment of human excreta-based biofertilizers for food production.

A total of twenty mixtures of weed, B-Lac and molasses were prepared in order to evaluate an accelerated liquid fertilizer (ALF) based on these plants. A mixture of 85% weed: water (1:1), 10% molasses and 5% B-Lac showed the best characteristics and was reproduced at a pilot scale. ALF was applied to lettuce using the following treatments: one foliar application per week of 10 mL L-1 (FA1), two foliar applications per week of 10 mL L-1 (FA2), one drench application of 50 mL L-1 every week (DA1), a drench application of 50 mL L-1 every two weeks (DA2) and a control without application (CWA). The variables evaluated were total yield, commercial yield, fresh weight, height, head diameter, percentage of dry matter and the concentration of foliar nitrogen, phosphorus, and potassium. The mixtures in the laboratory and pilot phase were evaluated in a completely randomized design. The field phase was assessed in a completely randomized block design with five treatments and four replications. No significant differences were found between the treatments, except in the percentage of dry matter and potassium content, where FA2 showed the best results (2.35% and 541 mg plant-1, respectively). The highest total yield (26.4 t ha-1) and commercial (24.11 t ha-1) were achieved with DA2; however, the nutritional content was lower than that in the other treatments. Using homolactic fermentation it was possible to recycle weeds and produce ALF, which has potential as a biofertilizer according to its chemical characterization and effects shown on lettuce cultivation.

Urbanization may lead to changes in assemblage and result in shifts in trait distribution from natural habitats to highly urbanized habitats. The shift in functional traits can affect ecosystem functions in urban areas. This study explored the foraging period of ants over 72 h and determined the relationship between the behavioral, morphological, and physiological traits of local foragers ants and environmental conditions in urban and forest sites. In addition, this study examined the ants’ ecosystem functions and compared it with that of their forest counterparts. Our results revealed that the foraging period of ants (i.e., Cardiocondyla sp.1, Monomorium chinense, Paratrechina longicornis, Pheidole megacephala, and Solenopsis sp.1) in urban areas peaked between 0900 and 1500 and that of some ants (i.e., Carebara diversa, P. megacephala, Pheidole fervens, Plagiolepis longwang, and Nylanderia sp.1) in forest areas was constant over time. For urban ants, a weak correlation was observed between foraging period and body size traits (i.e., Weber’s length and head width). This finding indicates that the major factor underlying the change in the foraging period might not be related to body size. Rather, the change may be attributed to synchronization between food availability and human activity (waste disposal; i.e., between 0900 and 1800). The shift in the functional traits of ants affects ecosystem functions in urban areas. In urban areas, although only one predatory ant species (P. megacephala) was sampled, its activity density was high. Most of these individuals were active during the daytime, indicating that the predatory behavior of ants in the novel urban environment has decreased temporally and is limited to the daytime. Urban ants tended to choose smaller food particles, whereas forest ants preferred larger food particles and had a twofold higher food removal rate.

Microgreens are emerging specialty crops becoming increasingly popular for their rich nutrient profile and variety of colors, flavors, and textures. The growing medium is a significant key factor in microgreen yield, quality, and sustainability. The widespread use of peat-based media raises questions regarding the environmental sustainability of microgreens production, and new substrates that are more sustainable are required. To this purpose, a study was designed with the objective of comparing eight alternative growing media evaluating their physicochemical properties and effect on yield, mineral profile, and nutritional quality of peas and radish microgreens. Tested substrates included a standard peat and perlite mixture (PP), coconut coir (CC), spent mushroom compost (SMC), organic waste compost (CMP), and 50:50 (v:v) mixes of PP and SMC, PP and CMP, CC and SMC, and CC and CMP. The physicochemical properties widely differed among the alternative substrates tested. SMC had high electrical conductivity and salt concentration, which resulted in poor seed germination. Growing media tested significantly influenced the production and nutritional quality of both microgreen species and variations were modulated by the species. With a 39.8% fresh yield increase or a small yield decrease (-14.9%) in radish and peas, respectively, PP+CMP (50:50, v/v) mix provided microgreens of similar or higher nutritional quality than PP, suggesting the potential of substituting at least in part peat with CMP. Using locally available CMP in mix with PP could reduce the microgreens industry reliance on peat while reducing costs and improving the sustainability of the production of microgreens. Further research is needed to evaluate also the potential economic and environmental benefits of using locally available organic materials like CMP as alternative growing media and peat-substitute to produce microgreens.

Sustainable food production has become increasingly important. Soilless cultivation systems offer several advantages, such as water and nutrient use efficiency, and can be implemented where traditional agriculture is impossible. Bioponic systems use locally or regionally available nutrient sources from organic waste streams (either fluid or solid) and can thus contribute to closing nutrient cycles locally. Bioponics harnesses the metabolic processes of microorganisms which release nutrients from organic matter. This study aimed to set up a bioponic system, by using biogas digestate concentrate and biochar as nutrient sources, and promoting nutrient release from the organic sources by including a biofilter in the system. The development of water quality, plant growth, and quality was monitored extensively. In addition, the influence of either the fungal biocontrol agent Trichoderma atrobrunneum or UV-C treatment of the nutrient solution on plant health and growth was investigated. Three cultivation cycles with Lactuca sativa ("HAWKING" Salanova®) in bioponic (BP), hydroponic (HP), and soil (SO) cultivation were performed. The study showed that healthy lettuces could be produced in BP systems, using a biogas digestate concentrate and biochar as nutrient sources, despite salt accumulation in the nutrient solution. In plant sap analyses, lettuces cultivated in BP systems contained less nitrate but more ammonium and chloride. The yield of the lettuces grown in the BP systems was intermediate, compared to the HP and the SO. The fungus, T. atrobrunneum, strain, T720, survived in soil and soilless cultivation systems. Compared to the HP and the SO systems, the shoot height of lettuces grown in the BP system, with the application of Trichoderma, was significantly increased. In SO systems with Trichoderma application, a significantly higher chlorophyll and flavonoid content, but significantly lower shoot height was observed. The fresh weight of lettuce roots was significantly higher in HP systems with Trichoderma treatment. Cultivating plants by using organic waste streams requires commitment and experience from producers. In BP systems, a biofilter (either within the system or externally, to increase nutrient levels) can help to rapidly convert the ammonium-rich fertilizer to plant-available nutrients. Unlike conventional HP systems, in BP systems, nutrients are released slowly over time, requiring close monitoring and adjustments. In conclusion, healthy lettuces for human consumption can be produced in BP systems, and the application of the biocontrol agent used has some beneficial influence on plant growth. [ABSTRACT FROM AUTHOR]