Search Results (53)

With the global emphasis on sustainable growth and development, the depletion of natural energy reserves due to reliance on fossil fuels and non-renewable sources remains a critical concern. Despite strides in transitioning to electrical mobility, rural and agricultural communities depend heavily on liquefied petroleum gas and firewood for cooking, lacking viable, sustainable alternatives. This study focuses on community-led efforts to advance biogas adoption, providing an eco-friendly and reliable energy alternative for rural and farming households. By designing and developing balloon-type anaerobic biodigesters, this initiative provides a robust, cost-effective, and scalable method to convert farm waste into biogas for household cooking. This approach reduces reliance on traditional fuels, mitigating deforestation and improving air quality, and generates organic biofertilizer as a byproduct, enhancing agricultural productivity through organic farming. The study focuses on optimizing critical parameters, including the input feed rate, gas production patterns, holding time, biodigester health, gas quality, and liquid manure yield. Statistical tools, such as descriptive analysis, regression analysis, and ANOVA, were employed to validate and predict biogas output data based on experimental and industrial-scale data. Artificial neural networks (ANNs) were also utilized to model and predict outputs, inspired by the information processing mechanisms of biological neural systems. A comprehensive database was developed from experimental and literary data to enhance model accuracy. The results demonstrate significant improvements in cooking practices, health outcomes, economic stability, and solid waste management among beneficiaries. The integration of statistical analysis and ANN modeling validated the biodigester system’s effectiveness and scalability. This research highlights the potential to harness renewable energy to address socio-economic challenges in rural areas, paving the way for a sustainable, equitable future by fostering environmentally conscious practices, clean energy access, and enhanced agricultural productivity. Full article

This study evaluated how fruit fermentation liquid (FFL) enhances the conversion of chicken manure by black soldier fly larvae (BSFL) and modulates their gut microbiota. Three groups were tested: control (A: 300 g manure + 50 g water), low-dose FFL (B: 300 g manure + 25 g FFL + 25 g water), and high-dose FFL (C: 300 g manure + 50 g FFL). The results show that the dry matter conversion rate significantly increased by 9.5% (p < 0.05), while the feed-to-larvae ratio was reduced by 1.02 (p < 0.01) in group C. NH₃ emissions in group C decreased by 24.48 mg·kg⁻¹·DM (dry matter substrate) day⁻¹ (24.48 mg per kilogram of dry matter substrate per day) (p < 0.01), with suppressed H₂S release. Gut microbiota analysis revealed that FFL reduced the abundance of Proteobacteria (6.07% decrease in group C) while enriching Actinobacteriota (4.68% increase) and beneficial genera (Corynebacterium, Gallicola). Substrate microbial diversity in group C improved, with Proteobacteria and Firmicutes increasing by 11.07% and 4.83%, respectively, and pathogenic Sphingobacteriaceae declining by 21.16% by day 7. FFL likely introduced organic acids and nutrients, enhancing larval digestion and nutrient absorption while inhibiting the production of harmful gases. These findings demonstrate that FFL optimizes BSFL-driven waste conversion efficiency through modulation of the microbiota, offering a sustainable strategy for organic waste management and contributing to circular agricultural systems. Full article

Rearing broiler chickens generates large quantities of waste material in the form of bedding. Anaerobic digestion (AD) is a technology that can be applied to this waste. This study aimed to evaluate the AD of broiler litter, either screened (S) or unscreened (US), from different flocks, collected from each production batch, totaling nine, from a commercial farm. Anaerobic digestion was conducted in batch biodigesters, and fraction separation was performed through screening prior to loading. The S substrate from the second and fifth flocks did not produce biogas. Reductions in total (TS) and volatile solids were highest for S substrates from the third flock (50.5% and 58.3%, respectively). Only the third flock’s S substrates showed greater reductions in solids than the US substrates. Potential biogas and methane production were also highest in the third flock’s bedding for both the S substrate (336.8 and 218.2 L/kg of TS, respectively) and the US substrate (296.8 and 213.4 L/kg of TS, respectively). The methane concentration in the S substrate was highest in the third flock (64.8%), while in the US substrate, it was highest in the third and fourth flocks (70.3%). Screening the litter reduced the process efficiency. We conclude that fraction separation is inadvisable for broiler litter. Full article

In the process of biogas production, various types of substrates with suitable energy potential are utilized to generate biogas in plants designed for cogeneration (CHP) of electricity and heat. This paper presents a literature review focused on different substrates involved in biogas production, emphasizing their optimization potential. Data for this research were gathered through a comprehensive review of scientific and scholarly literature from global databases. The study examines the biogas production capabilities of various feedstocks employed in cogeneration plants, highlighting the energy potential of substrates, including livestock byproducts such as liquid and solid manure, energy crops, organic waste from the food and slaughterhouse industries, as well as municipal wastewater and solid organic waste. Furthermore, we conducted a practical case study in the municipality of Čačak, which provides valuable insights into effective practices and strategies that can be broadly applied to enhance biogas production in similar contexts. The findings reveal significant variations in biogas production potential among different substrates, emphasizing the importance of strategic selection and management practices. This study contributes to the field by providing a clearer understanding of the substrate optimization process and practical insights that can inform the development of more effective biogas production strategies in local municipalities. Full article

Cheese production generates a large amount of liquid waste called cheese whey (CW). The management of CW is not optimized in Ecuador since a large proportion of it is discharged into the soil or effluents, causing significant environmental impacts. For this reason, the co-composting of whey with solid organic wastes can be a suitable method for its treatment for small companies generating this liquid waste due to its effectiveness and low cost. In this study, we analyzed 10 CW samples from different small companies in the Mocha canton (Tungurahua, Ecuador) to determine specific physicochemical and chemical parameters. Subsequently, a waste pile was formed with crop residues (corn and beans) and cow manure, which was composted using the turned pile composting system. Throughout the composting process, the temperature of the pile was controlled, its moisture was maintained between 40 and 60% by adding whey, and several physicochemical, chemical, and biological properties were determined. The results showed that the CW presented a high organic load, notable macronutrient content, and low heavy metal concentrations, all of which are beneficial for its co-composting with other organic solid wastes. The only limiting factors involved in using large amounts of whey in the composting process were the low pH values of the acid CW and the high concentrations of salts. It was also observed that co-composting CW with agro-livestock wastes was a viable strategy to treat these wastes and produce compost with stabilized and humified organic matter and remarkable agricultural value. Full article

Climate change is a contemporary global challenge that requires comprehensive solutions to mitigate its adverse effects. All human activities contribute to climate change, mainly through atmospheric emissions of greenhouse gases (GHGs), such as nitrous oxide (N₂O), carbon dioxide (CO₂), and methane (CH₄). While most of these emissions are primarily due to fossil fuel use, agriculture and livestock production also contribute to a significant share of approximately 12% of global emissions. Most processes that are implemented within an animal husbandry unit are associated with greenhouse gas emissions, including manure management. This review explores the interconnection between climate change and manure management practices, highlighting the potential for sustainable approaches to mitigating GHG emissions. The key strategies for manure management, such as anaerobic digestion, nutrient management, composting, manure separation and treatment, and improved storage and handling, are discussed, as they are implemented in different livestock production systems (ruminants, poultry, and pigs). Despite the technological progress, there is still a place for further improving manure management approaches, especially in non-ruminant species leading to a higher mitigation potential and a reduction in greenhouse gases emissions. Moreover, policy support and incentives for sustainable practices are crucial for widespread adoption. Full article

The aim of this study was to assess the impact of the method of use and different fertilization of the foothill soil on the manganese (Mn), copper (Cu), cadmium (Cd) and lead (Pb) concentration in leachates and the loads of trace elements leached from the soil profile. An experiment was carried out in Wiśnicz Foothills (Malopolska Province, Poland). In each plot, three lysimeters were installed, placed at a depth of 0–30 cm. The experiment included six variants, five on meadow, without fertilization (A—control); with mineral fertilization (B); with liquid manure (C) and with manure application (D); non-fertilized and non-mowed (E); and on arable land with mineral fertilization (F), in three repetitions each. Leachates were collected for three years in three periods: I—intensive growing, II—slow growing, and III—non-growing seasons. In general, the highest concentrations of Mn, Cu, Cd and Pb were recorded in leachates during period III. The lowest amounts of Cu and Cd were found in leachates in period II and Mn and Pb in period I. The exception were leachates from the following treatments: fertilized with liquid manure, which contained the most Mn and Cd in period II and the least Cd in period I; unused meadow, which contained the least Pb in period I; and leachates from arable land contained the least Cd in period I. The differences in the content of trace elements in the leachates were significant and amounted to 150–200% for Cd and Pb and about 20% for Mn and Cu. Mineral fertilization generally did not affect significantly Mn, Cu, Pb and Cd content in relation to the control, and the contents of Mn, Cu and Pb were even lower than in the leachates from the control. There was a significant increase in Mn concentration in leachates from unused meadow and arable land, Cu, Pb and Cd after both natural fertilizer applications and from arable land compared to other objects, in addition to Cd from unused meadow. Generally, the highest loads of trace elements were removed in period II and the smallest in period I of the study. Differences in leached loads during these periods were 2- to 8-fold and greater after liquid manure and manure application. The differences in Mn, Cd and Pb loads in subsequent years were 1.5- to 2-fold, and Cu loads in all years were similar. Natural fertilizers increased the trace element loads 1.5–4-fold compared to the control. Smaller differences concerned Mn and Cu and larger Pb loads. The method of land use significantly affected the quantity and quality of water percolates through the soil profile. Contrary to popular belief, the leachates from the unused meadow were not of the best quality, which resulted from their increased permeability into the soil under these conditions. Due to the quantity and quality of leachate waters and surface runoff in the foothill and mountain areas, it is advisable to limit tillage treatments, and the rational use of meadows and pastures with moderate fertilization is recommended. It is important to emphasize the importance of the proper management of the use of foothill and mountain areas for the optimal supply of plants with trace elements. Substantial losses of microelements necessary for optimal plant development may require their use in the form of fertilizers, which will result in increased agricultural production expenditures, reduce economic effects and slow down the pace of achieving sustainable agriculture. Full article

The sustainable management of pig slurry (PS) in intensive farms is essential to reduce adverse environmental impacts and reduce the ecological footprint. If not managed properly, PS can release GHG/NH₃ gases into the atmosphere and contaminate waters. This study evaluates the impact of an integral management system with physical and biological stages to mitigate the impact of PS. The system resulted in effective PS traceability, studying its physicochemical properties. The synergism in the whole system allowed a decrease in the most analyzed parameters during the autumn, spring, and summer. The pretreatment contributed significantly to obtaining an appreciable percentage of reduction in the constructed wetlands of SS (99–100%), COD (56–87%), TN (50–57%), and PO₄³⁻ (88–100%). The emission values (g/m²/day) were 0–2.14 (CH₄), 0–473.76 (CO₂), 0–179.77 (H₂O), 0–0.265 (N₂O), and 0–0.195 (NH₃), highlighting the raw, separated and manure fractions with the highest values. It is concluded that the system proves to be a practical, low-cost, and efficient technique for the treatment of PS. It significantly reduces the concentration of nutrients, and the intercepted byproducts can be valuable for application to the soil. In addition, the system effectively reduces GHG/NH₃ emissions in decanted, purified, and wetland PS fractions. Full article

Odor emissions are a crucial component of atmospheric pollution. As odor is a sensory pollutant, its management and treatment are recalcitrant. A wet scrubber (WS) is an efficient technique for odor removal, but disposal of waste liquid discharge leads to secondary pollution and CO₂ emissions during transportation. In this study, a system consisting of WS and electrooxidation (EO) was developed and installed in a swine manure fermentation facility. The absorption and EO characteristics were estimated through the practical implementation of a bench-scale WS (BSW). For EO, a dimensionally stable anode and Cl⁻ were applied. When the BSW was operated without EO, an L/G ratio of 8.88 was essential for securing the simultaneous removal rate of the four odorants (hydrogen sulfide, methyl mercaptan, ammonia, and total volatile compound). With the operation of the EO, the period to change the liquid based on equilibrium was postponed due to the continuous oxidation of the odorants absorbed in the liquid. As the applied current increased, the change period was further prolonged. However, the oxidation and absorption rates differed depending on the odor substances, due to differences in their physicochemical characteristics. Hydrogen sulfide and methyl mercaptan exhibited similar absorption and oxidation rates. Ammonia had a high absorption rate and a low oxidation rate. The acetaldehyde oxidation rate was the most sluggish among the substances. These findings demonstrate that simultaneous consideration of Henry’s constant and the reactivity of the target pollutant with HOCl renders the design of BSW appropriate for treating odor gases containing various odorants. This study contributes to efforts to address environmental problems concerning odors and also to global climate threats. Full article

Conventional fertilizer management can destroy the structure of soil. Replacing chemical fertilizers with organic fertilizers can improve soil quality and nitrogen use efficiency. We aimed to study the effects of organic fertilizer substitutions for chemical nitrogen fertilizer on soil fertility and nitrogen use efficiency in order to clarify the effectiveness of the available nutrient management measures in improving soil quality and increasing foxtail millet yield. A field experiment was carried out over two consecutive years, and a total of six treatments were set up: no fertilizer (CK), chemical nitrogen fertilizer alone (N), the substitution of 25% of chemical nitrogen fertilizer with bio-organic fertilizer (N25A1), the substitution of 25% of chemical nitrogen fertilizer with fermented mealworm manure (N25B1), the substitution of 50% of chemical nitrogen fertilizer with bio-organic fertilizer (N50A2), and the substitution of 50% of chemical nitrogen fertilizer with fermented mealworm manure (N50B2). The results of this study show the following: (1) Compared with chemical nitrogen fertilizer, the substitution of organic fertilizer for nitrogen fertilizer reduced the bulk density and solid phase of the soil, and it increased the total porosity, water content, liquid phase, and gas phase of the soil. (2) Compared with nitrogen fertilizer, the use of an organic fertilizer increased the contents of nitrate nitrogen, ammonium nitrogen, and total nitrogen in the soil by 13.59~52.56%, 4.47~18.27%, and 4.40~12.09%, respectively. The content of alkaline nitrogen increased by 1.70~32.37%, and the contents of soil available potassium, available phosphorus, and organic matter also increased. (3) The activities of sucrase, urease, glutaminase, and asparaginase were improved by replacing chemical nitrogen fertilizer with organic fertilizer. The N25 treatments performed better than the N50 treatments, and fermented mealworm manure performed better than biological organic fertilizer. (4) A moderate application of organic fertilizer (N25) can increase the grain yield, ear weight, grain weight, and 1000-grain weight of foxtail millet, whereas excessive application of organic fertilizer (N50) can reduce foxtail millet yield. (5) Replacing chemical nitrogen fertilizer with organic fertilizer can improve the agronomic use efficiency, physiological efficiency, biased productivity, harvest index, and apparent use efficiency of nitrogen fertilizer. In this study, the substitution of 25% of chemical nitrogen fertilizer with fermented mealworm manure was the best combination for restoring crop productivity and soil quality. Full article

The study aimed to determine the influence of grassland management on the potential food base of the red-backed shrike Lanius collurio and the condition of chicks in the population inhabiting semi-natural grasslands in the Narew floodplain. The grassland area was divided into three groups: extensively used meadows, intensively used meadows fertilised with mineral fertilisers, and intensively used meadows fertilised with liquid manure, and selected environmental factors that may influence food availability were determined. Using Barber traps, 1825 samples containing 53,739 arthropods were collected, and the diversity, abundance, and proportion of large arthropods in the samples were analysed depending on the grassland use type. In the bird population, the condition of the chicks was characterised by the BCI (Body Condition Index) and haematological parameters (glucose level, haemoglobin level, haematocrit, and H:L ratio). The diversity of arthropods was highest in extensively used meadows. Still, the mean abundance and proportion of arthropods over 1 cm in length differed significantly for Orthoptera, Hymenoptera, Arachne, and Carabidae between grassland use types, with the highest proportion of large arthropods and the highest abundance recorded in manure-fertilised meadows. The highest Body Condition Indexes and blood glucose levels of nestlings indicating good nestling nutrition were recorded in nests of birds associated with extensive land use. The H:L ratio as an indicator of the physiological condition of nestlings was high on manure-fertilised and extensively managed meadows, indicating stress factors associated with these environments. This suggests that consideration should be given to the effects of chemicals, such as pesticides or drug residues, that may come from slurry poured onto fields on the fitness of red-backed shrike chicks. Full article

In view of rising global demand, energy is becoming a significant cost factor in industry and society. In addition to the global players China, India, and the USA, Africa will also become a driver of the world’s primary energy demand in the future due to the rapidly growing developing countries. In addition to the armed conflicts in Ukraine and the Middle East, global energy markets are tense and volatile due to inflation and higher borrowing costs. Because of society’s desire to phase out the use of fossil fuels, the use of renewable energies is increasingly taking center stage worldwide and especially in Germany. Rural areas and agriculture, especially energy-intensive livestock farms, are particularly affected by this development and are therefore faced with additional economic challenges. Additional energy can be generated by using photovoltaic systems on the roofs of farm buildings or by utilizing the liquid manure from livestock farming in biogas plants. For these farms, such alternative sources of energy could open previously untapped potential and additional synergies for using their own inexpensive energy on the farm or supplying surplus electricity directly to the public grid as a market participant. Agriculture could thus serve as an actor in a decentralized energy supply and thus build up regional energy networks. However, intelligent electricity storage concepts and a corresponding energy management system (EMS) are essential to be able to utilize the potential for renewable energy generation at all, to coordinate both internal production processes and the varying energy demand and supply on the electricity grid. As agricultural production processes differ greatly from farm to farm and region to region, the introduction of an energy management system is strongly dependent on user acceptance. The purpose of this study is to use the web-based software tool ADOPT (CSIRO 2018) to predict the level of acceptance and the duration of the market launch of an EMS based on the region of Bavaria. Individual important influencing factors for the subsequent regional marketing concept are also identified. Full article

Emission quantification from the agricultural sector, and especially from livestock manure management, is relevant for assessing mitigation strategies and for inventory purposes. There are different direct techniques used to monitor emissions from quiescent surfaces. Common techniques include the closed static chamber and the open dynamic chamber. The aim of this study was to evaluate and compare different direct methods, two dynamic hoods and one static hood, for monitoring NH₃ and greenhouse gas (GHG) emissions (N₂O, CO₂, and CH₄) from different emission sources. These sources are ammonia solutions and different by-products of manure (compost, liquid fraction of digestate, and solid fraction of pig slurry). The use of dynamic hoods, despite their differences in size, operation, and applied air flux, presents comparable emission rates for all emissions and compounds assayed. These rates are always higher than those obtained using static hoods. Therefore, it can be concluded that the use of dynamic hoods is a valuable technique for refining the indirect estimation of emissions. Full article

Currently, there are no standard management practices to counteract the adverse effects of fumigation on the soil microbiome. In this study, a variety of pre-plant soil amendments were examined for their ability to recruit and maintain apple rhizosphere microbiomes that are suppressive to pathogen re-infestation of fumigated orchard soils. The capacity of these amendments to improve other characteristics of soil productivity was also evaluated. Results suggest that composted chicken manure and liquid chitin are likely to be detrimental to plant and soil health when used as a post-fumigation soil amendment. In comparison, insect frass (IF) resulted in a significant increase in tree trunk diameter relative to the fumigated control. Following pathogen re-infestation of fumigated soil, however, IF induced a significant increase in Pythium ultimum in the rhizosphere. Therefore, IF can benefit the growth of young apple trees in fumigated soil but may stimulate pathogen activity upon re-infestation. To date, the possibility of using soil amendments to suppress pathogen re-infestation of fumigated soils has not been tested. Results from this study ground support the use of soil amendments as an intervention strategy for “steering” the soil and rhizosphere microbiome in more beneficial and/or prophylactic directions following fumigation. Full article

Livestock manure has a high ammonium content that can limit its direct application on soil as a fertiliser in nitrate-vulnerable zones. Treatment technologies that are able to extract ammonium from livestock manure allow it to be concentrated in small volumes, making it cheaper and easier to transport and use as fertiliser in crop areas where there is a deficit of nitrogen. This study proposed using low-temperature vacuum evaporation to treat pig slurry in order to obtain marketable products that can be used as fertilisers and help close the nitrogen cycle. Two different configurations and scales were used. The first was a seven-litre laboratory-scale evaporator complemented with a condenser, a condensate trapper, an acid trap and a vacuum pump operated at −90 kPa vacuum pressure and at three different temperatures: 50.1 ± 0.2 °C, 46.0 ± 0.1 °C and 45.3 ± 1.3 °C. The second, Ammoneva, is an on-farm pilot-scale evaporator (6.4 m³), capable of working in four-hour batches of 1 t of liquid fraction of pig slurry with an operating temperature of 40–45 °C and −80 kPa vacuum pressure. The laboratory-scale evaporator, which features several novel improvements focused on increasing ammonia recovery, showed a higher nitrogen removal efficiency from the liquid fraction of pig slurry than the on-farm pilot plant, achieving 84% at 50.1 °C operation, and recovering most of it in ammonia solution (up to 77% of the initial nitrogen), with 7% of the ammonia not recovered. The Ammoneva pilot plant achieved a treated liquid fraction with 41% of initial nitrogen on average, recovering 15% in the ammonia solution in the acid trap; so, the NH₃ gas absorption step needs to be further optimised. However, due to the simplicity of the Ammoneva pilot plant, which is easily placed inside a 20-foot container, and the complete automation of the process, it is suitable as an on-farm treatment for decentralised pig slurry management. The implementation of the novel design developed at laboratory-scale could help further increase recovery efficiencies at the pilot-plant scale. Full article