Search Results (80)

Cattle manure accounts for approximately one-third of the total livestock manure produced in the Republic of Korea and is typically composted. To elucidate its feasibility as a renewable resource, this study evaluated the conversion of cattle manure into a solid biofuel and the nutrient recovery potential of its combustion residues. Solid fuel was prepared from cattle manure collected in Gyeongsangbuk-do, Korea, and its fuel characteristics and ash composition were analyzed after combustion. Combustion tests conducted using a dedicated solid fuel boiler showed that an average lower heating value of 13.27 MJ/kg was achieved, meeting legal standards. Under optimized combustion, CO and NO_x emissions (129.9 and 41.5 ppm) were below regulatory limits (200 and 90 ppm); PM was also within the 25 mg/Sm³ standard. The bottom ash contained high concentrations of P₂O₅ and K, and its heavy metal content was below the regulatory threshold, suggesting its potential reuse as a fertilizer material. Although the Zn concentration in the fly ash exceeded the standard, its quantity was negligible. Therefore, the solid fuel conversion of cattle manure can become a viable and environmentally sustainable solution for both bioenergy production and nutrient recycling, contributing to improved waste management in livestock operations. Full article

Anaerobic acidogenic fermentation presents a promising approach for sustainable carbon emission mitigation in livestock waste management, addressing critical environmental challenges in agriculture. This study systematically investigated the synergistic effects of composting-assisted pretreatment coupled with micro-aeration and methanogenesis suppression to enhance volatile fatty acid (VFA) production from swine manure supplemented with wheat straw, valorizing agricultural waste while reducing greenhouse gas emissions. The experimental protocol involved sequential optimization of pretreatment conditions (12 h composting followed by 10 min thermal pretreatment at 85 °C), operational parameters (300 mL micro-aeration and 30 mmol/L 2-bromoethanesulfonate (BES) supplementation), and their synergistic integration. The combined strategy achieved peak VFA production (5895.92 mg/L, p < 0.05), with butyric acid constituting the dominant fraction (2004.42 mg/L, p < 0.05). Enzymatic analysis demonstrated significantly higher activities of key hydrolytic enzymes (protease, α-glucosidase) and acidogenic enzymes (butyrate kinase, acetate kinase) in the synergistic treatment group compared to individual BES-supplemented or micro-aeration-only groups (p < 0.05). This integrated approach provides a technically feasible and environmentally sustainable pathway for circular resource recovery, contributing to low-carbon agriculture and waste-to-value conversion. Full article

A significant amount of livestock manure is generated in Bangladesh, creating challenges for sustainable manure management. Bioenergy and organic fertilizer production from manure are expected to provide opportunities for renewable resources, including environmental benefits. Therefore, this research aimed to spatially assess the potential of manure for biogas and compost using GIS (geographic information system) symbology and hot spot analyses, based on theoretical estimations. This study identified hot spots for biogas and compost production from various types of livestock manure at the district and sub-district levels, whereas previous studies have only explored these at a national level. The estimated total biogas and compost potential was approximately 15,035.50 million m³ and 67.36 million tons, respectively, from livestock manure in 2024, distinguishing it as a feasible alternative to fossil fuels for electricity generation and synthetic fertilizers for crop production. Overall, the regional pattern maps of the socio-economic potential, hot spot identification, and environmental benefits assessments of manure will provide a more localized approach to planning sustainable manure management strategies for biogas and compost production in Bangladesh. Full article

Fenugreek (Trigonella foenum-graecum L.) is an emerging forage crop known for its high nutritional value and adaptability to diverse environmental conditions, making it a promising alternative in sustainable livestock feeding systems in the Mediterranean region. A field experiment was established at the Agricultural University of Athens during the growing season 2020–2021 in a split-plot design with five fertilization treatments (Biocyclic-Vegan Humus Soil; BHS, Farmyard Manure; FMA, Organic Compost; OCP, Inorganic Fertilizer; IFZ, and No Treatment Control; CTRL, and two main salinity treatments (High Salinity Level; HSL, and Normal Salinity Level; NSL). The Forage Quality Index (FQI) was the highest under BHS at NSL (45) and lowest under CTRL at HSL (32), emphasizing the positive impact of organic fertilization. Crude ash (CA) was higher under NSL (9.7%), with OCP and IFZ performing best, while salinity reduced CA under CTRL. Crude fiber (CF) increased under salinity, particularly with OCP and IFZ, whereas BHS and FMA at NSL showed the lowest CF (15.8%), enhancing digestibility. Total fat (TF) was the highest under BHS and FMA at NSL (5.8%) and lowest under IFZ and CTRL at HSL (4.0%), underscoring the importance of balanced fertilization in maintaining fat content. These results highlight the potential of organic amendments to improve nutrient availability, digestibility, and overall feed value. Full article

Organic fertilizers are a revolutionary concept in coconut farming as they provide a package for sustainable coconut production. This review examines the multiple advantages of organic fertilization methods and types of organic fertilizers, which include compost, vermicompost, livestock manure, green manure, crop residues, and biofertilizers. The review focuses on the best practices, application methods, time of application, frequency and rate of application of nutrients for coconut palm at various developmental stages. The study provides a detailed and systematic review of the environmental, economic and social impacts of organic fertilization. Benefits include enhanced soil health, biodiversity promotion, carbon sequestration, cost effectiveness, quality improvement of the yield, food security and possibilities of creating rural income. Issues including resource accessibility difficulties, nutrient deficiencies, and intensive labor requirements are explored in detail, as well as future trends that focus on advanced technologies, new research areas, and policy approaches. Thus, the study reviews organic fertilization as a coherent concept that can be applied to coconut production and other goals of environmental protection, food security, and sustainable development of agriculture. Full article

The global production of brewers’ spent grains (BSG) is 37 million tons yearly. Composting represents an eco-friendly method to manage and valorize organic by-products in a circular economy model. This project aims to compare two BSG bin-composting mixtures (BSG and wheat straw with pig slurry solid fraction, MIX1, or sheep manure, MIX2) and approaches (manual turning, MT, and static composting, ST). The two mixtures’ physicochemical characteristics and greenhouse gas (GHG) emissions were assessed during the process. The evolution of physicochemical properties is reported in detail. Headspace samples of GHG emissions were collected and analyzed with gas chromatography coupled with specific detectors. Carbon dioxide (CO₂) emissions were 34.3 ± 0.03 and 31.0 ± 0.06 g C kg⁻¹ fresh matter (FM) for MIX1-MT and MIX2-MT, and 28.8 ± 0.01 and 31.2 ± 0.02 g Ckg⁻¹ FM for MIX1-ST and MIX2-ST. Methane emissions were negligible (all conditions < 0.086 ± 0.00 mg C kg⁻¹ FM). Nitrous oxide (N₂O) emissions from composting are affected by the substrate, bulking material, pile dimension, and manure. Particularly, the total emissions of N₂O, estimated as CO₂ equivalents, were 45.8 ± 0.2 and 63.0 ± 0.4 g CO₂ eq kg⁻¹ FM for MIX1-MT and MIX1-ST, respectively. In both composting approaches, MIX2 showed a low CO₂ equivalent (1.8 ± 0.02 and 9.9 ± 0.05 g CO₂ eq kg⁻¹ FM for MT and ST), likely due to incomplete decomposition. The bin-composting process represents a solution for recycling and reusing organic waste and livestock manure in small to medium-sized breweries. The solid fraction of the pig slurry resulted in the most suitable manure. 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

Composting is an environmentally friendly method for transforming the nutrients present in livestock manure into organic fertilizer. In this study, the compost quality-enhancing and N₂O and CH₄ emissions-reducing effects of superphosphate were investigated during industrial-scale in-vessel composting of swine manure. Alongside a control group, three different doses of superphosphate were tested: 5% (SSP5), 10% (SSP10), and 15% (SSP15). The results revealed that the superphosphate reduced the N₂O and CH₄ emissions by 18.5–26.3% and 15.8–25.1%, respectively. In addition, the superphosphate enhanced both the N and P contents of the compost. However, it had an adverse impact on compost maturity, with the SSP15 dose showing the lowest germination index (GI) at 70.4% and the highest electrical conductivity (EC) at 9.04 mS·cm⁻¹. These findings suggest that superphosphate has potential for greenhouse gas mitigation and nutrient augmentation in industrial composting. Although the economic benefits of superphosphate addition for GHG reduction are limited, the technology holds considerable economic potential for nitrogen conservation. Further investigations should focus on combining superphosphate addition with other improvements, considering both compost quality and economic viability. Full article

This experiment takes typical chernozem soil as the research object to investigate the effects of adding various livestock and poultry manures during in situ strip composting of corn straw on the decomposition characteristics of the straw and the soil organic carbon content. This study set up a total of four treatments under the condition of following the equal carbon principle: (1) corn straw (T1); (2) corn straw + chicken manure (T2); (3) corn straw + cow dung (T3); (4) corn straw + decomposition agent (T4). The cumulative mass loss rate of straw in the treatment of adding livestock and poultry manure ranged from 51.60% to 54.33%, with a carbon release rate of 75.34% to 76.64%. Correlation analysis revealed a significant positive relationship between SOC, straw mass loss rate, and straw carbon release rate. Furthermore, there was a significant positive correlation between organic carbon components such as DOC, EOC, POC, and MBC with CPMI, while showing a significant negative correlation with the oxidation stability coefficient (KOS). Incorporating corn straw into livestock and poultry manure and returning it to the field in in situ strips effectively enhances the decomposition process of straw, leading to an increase in the organic carbon content of chernozem soil. Full article

Sustainable management of organic waste, such as food waste (FW) and livestock manure (LS), is essential for reducing pollution and promoting resource recycling. This study investigated the effects of Bacillus sp. inoculation and biochar addition on composting efficiency, microbial dynamics, and physicochemical properties. Bacillus sp. accelerated the breakdown of cellulose and lignin, reduced moisture content, stabilized pH, and mitigated ammonia volatilization. Biochar reduced ammonia emissions by 17.04%, increasing to 28.89% with Bacillus sp. Next-generation sequencing revealed Bacillus sp. enhanced microbial diversity, suppressed pathogens, and promoted beneficial microbial interactions. LS treatments retained Firmicutes dominance (up to 95.17%), improving nitrogen retention, while FW treatments transitioned to Proteobacteria and Bacteroidota, driving plant material decomposition. By day 35, Bacillus sp. increased late-stage microbial taxa (Deinococcota, Myxococcota), linked to cellulose degradation and pathogen suppression. In FW biochar compost (FWBC), Planococcaceae and Bacillaceae synergistically decomposed complex organic matter. LS biochar compost (LSBC) reduced anaerobic families like Clostridiaceae and Peptostreptococcaceae, lowering methane and hydrogen sulfide emissions. Microbial network analysis highlighted improved cooperation under Bacillus sp., with LSBC sustaining positive interactions at higher dosages. These results demonstrate that microbial inoculants and biochar enhance composting efficiency, nutrient cycling, and environmental sustainability. Full article

Dog and cat faeces are a globally neglected issue that demands proper management. The poor handling of pet waste not only impacts environmental health but also contributes to community conflicts due to insufficient waste management practices. The objectives were to investigate the properties of pet wastes compared to livestock wastes (pigs, hens, and cattle) with the intention of formulating an efficient compost product suitable for agricultural applications. Faeces from dogs and cats were collected from the community, while faeces from livestock (pigs, cattle, and hens) were collected from farms. Faeces were mixed with probiotics, rice bran, and rice husk to make compost and used to grow sweet corn plants. The nutrient content was compared between fresh and composted faeces. Composted manure from different animal sources was compared for its effectiveness in promoting sweet corn growth. The results showed that fresh and composted dog and cat manures contained higher levels of nutrients (p < 0.05) compared to livestock manures. Additionally, composted pet manure accelerated (p < 0.05) the growth of the plants compared to composted livestock manures and control groups. This is the first study to conclude that composted pet faeces surpass livestock manure in their higher nutrients and enhance plant growth. The findings could help reduce pet waste and transform it into a valuable recycled resource. However, the safety of composted manure, especially concerning toxoplasmosis from cat faeces, remains a significant concern and requires further investigation. Full article

Black Soldier Fly (Hermetia illucens) is well-known for having a high protein and lipid content during its larval stage and is cultivated for animal feed. Rearing Black Soldier Fly larvae (BSFL) produces byproducts known as frass and larval sheddings in large volumes with limited applications. Therefore, there is a need to identify viable sustainable management strategies to prevent potential environmental issues associated with their accumulation. Accordingly, the purpose of this study was to evaluate BSFL frass and larval sheddings as viable ingredients in composts that utilize additional nitrogen feedstocks. Four experimental compost piles (22.7 m³) with different ratios of BSFL frass and sheddings were developed based on previous research; two piles included 25% frass, whereas the other two included 30% frass. Across these piles, the inclusion of wood chips, food waste, and livestock manure varied to determine the best proportions for compost. The compost piles were maintained for five months, including a curing phase. After curing, samples from each pile were collected to analyze their pH, macro- and micro-nutrients, particle size, stability, and maturity. The findings indicated that the pH levels (7.1–8.1) and carbon-to-nitrogen ratios (10.40–13.20) were within the optimal ranges for all piles. The phosphorus levels (0.75–1.30%) of each pile exceeded typical ranges, likely due to the high phosphorus content of the frass itself. The moisture content varied widely (24.5–51.7%), with some piles falling below optimal levels. Stability and maturity tests yielded mixed results, with some piles demonstrating continued decomposition activity. Overall, the findings indicated that inclusion rates of 25–30% of BSFL frass and sheddings produced compost with generally favorable characteristics when high nitrogen feedstocks were also incorporated into the compost piles. These findings align with those from previous research and highlight both the potential and challenges of incorporating BSFL frass into compost production. Full article

Inner Mongolia has the largest sheep population among China’s provinces, resulting in the production of a substantial amount of sheep manure. If left untreated, this manure can contribute to environmental pollution. However, sheep manure serves a dual purpose: it can be both a pollutant and a valuable source of organic fertilizer. Consequently, there is an urgent need to address the environmental issues arising from manure accumulation and its unused status. In this paper, a viable solution is proposed: the conversion of manure into fertilizer through a composting unit incorporating high-temperature aerobic fermentation technology. This unit, tailored for small farms and individual farmers, integrates critical functions such as ventilation, heating, and turning. Additionally, it boasts excellent thermal insulation, enhancing composting efficiency and enabling precise control over fermentation conditions. This design mitigates heat loss and accelerates maturation, addressing common challenges in traditional composting. The design process encompassed both equipment construction and control systems, with a primary focus on compost fermentation and aeration heating. The components were carefully designed or selected based on theoretical analysis and subsequently validated using simulation software, including EDEM and Fluent. The control system seamlessly integrates a touch screen interface, PLC programming, and control circuits to manage air pumps and electric heaters in response to changes in temperature and oxygen concentration. Furthermore, it controls the motors during the recovery phase. A comprehensive performance evaluation was conducted, revealing notable improvements. Under artificially heated conditions, the maximum temperature of the compost increased by approximately 20 °C, the composting cycle was reduced by roughly 4 days, and the seed germination index (GI) rose by about 9% when compared to natural fermentation. Thus, this device significantly accelerates composting and improves fertilizer quality by increasing the decomposition rate. Full article

The rising demand for climate change mitigation has brought attention to agricultural systems focused on carbon farming and reducing emissions. Composting food wastes and livestock manure not only mitigates environmental concerns but also boosts soil fertility and crop yields as an alternative fertilizer. In this experiment, we investigated the effects of different fertilizer types (chemical and organic waste compost) and crop rotations (rice–fallow, rice–Italian ryegrass, and rice–potato) on rice production, nitrogen use efficiency, and soil carbon stocks. In this experiment, soil carbon and nitrogen retention were more influenced by compost nutrient levels than by crop rotation types. Overall, as the nitrogen levels increased, the rice yields improved with both chemical and organic waste fertilizers. Among the crop rotations, the rice–Italian ryegrass rotation showed a higher nitrogen use efficiency. Optimal fertility levels, balancing nitrogen use efficiency, yield, and soil carbon were observed between 523 and 582 kg N ha⁻¹ when combined with specific crop rotations. Moreover, soil total carbon and soil total nitrogen varied among crop rotation systems. Our results indicate that organic waste compost can be a potential alternative to chemical fertilizers, while crop rotations offer a viable approach for maximizing the environmental benefits. Full article