Cow Dung Research Articles

Evaluation of the Effectiveness of Various Ameliorant Sources in Increasing NP Absorption and Sweet Corn Productivity on Sandy Soil

Aims: This study aimed to determine the effectiveness of various ameliorant sources in enhancing NP uptake and the productivity of sweet corn (Zea mays L. saccharata) in sandy soil. Study Design: The study used a randomized block design with five treatments and four replications. Place and Duration of Study: The field experiment was conducted in a sandy soil area in Moncok Karya, Pejeruk Karya Village, Ampenan District, Mataram City. The analysis part was carried out in Microbiology laboratory, and in the Soil Physics and Chemistry Laboratory, Faculty of Agriculture, University of Mataram. All series of trials were completed in six months. Methodology: The experimental tested five treatments, namely; Control, no ameliorant (A0), Rice Husk Charcoal (AA), Cow Manure (AS), Compost (AK), and Fertile Organic Fertilizer (AP). Each treatment was replicated 4 times. Observations were made on biomass weight, crop yield, nutrient concentrations (N and P), nutrient uptake, and mycorrhizal activity. Results: Ameliorant treatment with cow manure significantly improved plant growth and productivity by enhancing nutrient availability in the soil. This included increases in biomass, and yield. Cow manure also promoted mycorrhizal activity, improved soil structure and increased nutrient absorption efficiency. Conclusion: The research result showed that the cow manure as an ameliorant markedly enhanced NP uptake and productivity of sweet corn in sandy soil. It improved soil fertility, supported mycorrhizal colonization, and strengthened plant resistance to environmental stresses.

Long-Term Effects of Crop Treatments and Fertilization on Soil Stability and Nutrient Dynamics in the Loess Plateau: Implications for Soil Health and Productivity

Soil degradation and erosion pose significant threats to agricultural sustainability in fragile ecosystems, such as the Loess Plateau in northern China. This study examines the long-term impacts of fertilization regimes and land-use systems on soil health, focusing on soil aggregate stability, fertility, and crop productivity. Six treatment combinations were evaluated in our study, including three continuous alfalfa fields (AL-CK, AL-P, and AL-NPM) and three continuous wheat fields (WH-NPM, WH-NP, and WH-P), each representing a combination of land use and three fertilization treatments: (1) no fertilization (CK), (2) inorganic fertilization (120 kg ha−1 N, 60 kg ha−1 P-NP), and (3) a combination of organic and inorganic fertilization (75 t ha−1 cow manure-NPM). Soil samples were collected from three depths (0–10 cm, 10–20 cm, and 20–30 cm) to assess physical and chemical properties. We evaluated the long-term effects of different fertilization treatments on soil stability, fertility, and crop yield to explore the interactions among soil’s physical and chemical properties under two land-use types and to assess the effectiveness of combined organic and inorganic fertilization strategies in improving soil health and mitigating erosion in vulnerable landscapes. The study revealed significant depth-specific variations with surface layers (0–10 cm) showing the greatest improvement under NPM treatments, particularly in continuous alfalfa fields, which exhibited higher soil fertility, improved soil structure, and crop yield. In contrast, continuous wheat fields with minimal fertilization demonstrated significantly lower soil quality and productivity. Using the combination of mineral fertilizers and organic amendments, such as cow manure, proved to be the most effective strategy for significantly enhancing nutrient availability and overall soil health. Partial Least Squares Modeling (PLS-M) and Mantel analysis highlighted the critical role of fertilization management in maintaining soil quality, boosting crop productivity, and mitigating erosion in high-risk areas. This study emphasizes the importance of integrated nutrient management for sustainable land use and soil conservation in erosion-prone regions.

Pelatihan Pengembangan SDM Untuk Optimalisasi Teknologi pada Desa Seri Bandung (Studi Kasus Emping Ubi Umak)

Human resource development for optimizing technology in Emping Ubi Umak micro, small, and medium enterprises (UMKM) focuses on efforts to improve the skills and performance of the workforce. The goal is to achieve optimal results in business or enterprise activities. The skills in question include technical, managerial, and soft skills such as communication and teamwork. By improving the right skills, employees will be able to work more efficiently and effectively and be able to adapt to market and technological developments. Therefore, to support the smooth running of the regional economy in developing Emping Ubi Umak UMKM from those not well-known or not widely known to consumers, this Emping Ubi Umak UMKM digitalization program can be a solution. The forms of Emping Ubi Umak UMKM currently developing in Seri Bandung Village are liquid fertilizer, basket/kendang collective gardens, shallot cultivation, cow dung biogas, collective gardens, and many more, especially in the food sector. By having more than 20 UMKM players, Seri Bandung Village has advanced economic potential by digitalizing UMKM.

Effects of Liquid Organic Fertilizer on Soil Chemistry, Components and Yields of Maize West of Burkina Faso, West Africa

Aims: The aim of this study is to help increase crop yields and soil fertility. Location and Duration of Studies: The study took place in the western part of Burkina Faso. It is based on the use of a liquid organic fertilizer on corn producers' plots. These are soil fertility data and corn agronomic data over three successive campaigns (2021, 2022 and 2023). Methodology: A completely randomized block design with three replications comprising five (05) Treatments was set up. The fertilizers used were : NPK (15-15-15), urea (46%N) and liquid organic fertilizer. The liquid organic fertilizer was made using cowpea flour, neem leaves, sugar and animal waste (cow dung and urine). Soil samples were taken at six periods. The first sample was taken before sowing, followed by four more during cultivation and one just after harvesting. Measurements of height and diameter of the rod were taken on the 30th, 45th, 60th and 75th day after sowing. Results: Results showed that T1 recorded the best pH-water value (6.75) and total phosphorus (410.66 mg/kg). The T4 gave the highest levels of organic carbon (1.5%) and total nitrogen (1.44%). Concerning the cation exchange capacity (CEC), the highest content is obtained with T2 with a value of 10.23 cmol/kg. As for total potassium, the highest content is in T3, at 652.44 mg/kg. At the maturity, T2 has the highest average diameter at 16.35 mm. In terms of height, the absolute control present the tallest plants with an average value of 1.41m. The highest yields were obtained with T4 (1983.23 kg/ha), followed by T2 (1834.9 kg/ha), T1 (1723.43 kg/ha) and T3 (1557.12 kg/ha). Liquid organic fertilizer has been effective in producing grain yields at a rate of 40.58%. Conclusion: The liquid organic fertilizer applied alone has high carbon, total nitrogen, total phosphorus, total potassium and CEC content compared with the control. It was also efficient in grain yield production with a rate of 40.58%. In fact, it is imperative to carry out a test in a paysan environment before popularizing it.

Enhancing green chili growth using eggshell waste as a carrier for NPK biofertilizer consortium in soil

Biofertilizer technology continues to be derailed by the short shelf life of inoculants. The survival efficiency of rhizobacterial inoculants in biofertilizer formulations dramatically depends on the choice of carrier material. The use of wastes as carriers for biofertilizer formulations is a commonly explored option because of their ready availability, cost-effectiveness and ability to affect soil health. The present study investigated the suitability of eggshell (ES) as a carrier for cow dung waste (CDC) and lignite (L) in the combined formulation of green chili plant growth using three rhizobacterial inoculants, namely, the N-fixing bacterium Enterobacter sp. GG1, the P-solubilizing bacterium Bacillus sonorensis GG2, and the K-solubilizing bacterium Lysinibacillus fusiformis GG3, under room-temperature conditions. The combination of eggshell and lignite supported the maximum viability of Enterobacter sp. GG1 (9.09±0.025 log CFU g-1), B. sonorensis GG2 (9.19±0.023025 log CFU g-1), and L. fusiformis GG3 (9.09±0.042025 log CFU g-1) under six-month room conditions. A new physiochemically formulated eggshell with an NPK consortium exhibited a significant correlation at the 0.05 significance level (2-tailed). Considering the results of this study on the optimization of green chili plants after two months of treatment under environmental conditions, the maximum growth of plants inoculated with the NPK consortium (ES+L) was 159.16% shoot and 40.58% root growth, with increased available plant nutrients in clayey soil (i.e., N 64.54±1.81 ppm, P 29.51±1.65 ppm, and K 73.95±6.43 ppm). The findings of this study highlight the potential of eggshell waste as a sustainable and effective carrier material for biofertilizer formulations, addressing waste management challenges to enhance rhizobacterial viability and improve nutrient availability in soil.

Ivermectin and Neem residues in cattle dung: Effects on dung beetle attraction and ecological functions in Brazilian pastures

AbstractIdentification of veterinary medical products carrying reduced risks to dung beetles remains a critical objective for the sustainable management of livestock parasites. Despite the essential role dung beetles play in tropical pasturelands, our understanding of the impact of alternative parasiticides, such as Neem plant extract, on dung beetle attraction and dung use is still limited. This study assessed the effects of dung from cattle exposed to Ivermectin (known to be harmful to dung beetles), Neem, and non‐exposed animals (control) on dung beetle assemblage and their ecological functions (dung removal and soil bioturbation), in introduced and native pastures in the Brazilian Cerrado. Our findings revealed similar patterns of dung beetle attraction to Ivermectin, Neem, and control dung in introduced pastures. However, in native pastures, dung beetles exhibited greater attraction to dung from Ivermectin and Neem‐treated cattle compared with the control. Telecoprid beetles displayed an increased attraction to Neem‐treated dung in native pastures, with two species demonstrating a preference for this dung type. Ecological function performance was higher in Neem‐treated dung compared with control, yet no significant difference was noted between Neem and Ivermectin in both pasture types. These results underscore the compelling attractiveness of cattle dung from Neem‐treated animals to dung beetles, concurrently ensuring the preservation of dung beetle ecological functions in both pasture settings. This highlights the need for a rigorous evaluation of novel protocols incorporating natural parasiticides, which emerge as important tools in the conservation of dung beetle biodiversity and their ecological functions in tropical pasturelands.

Utilization of Continuous Anaerobic Digesters for Processing Cattle Dung and Cabbage (Brassica oleracea) Waste

The purpose of this work is to explore the addition of cabbage (Brassica oleracea) waste interspersed with cattle dung into a continuous anaerobic digester that normally uses cattle dung as a substrate. In this work, a 200-L continuous anaerobic digester was operated to conduct the research. The digester was filled fully with a mixture of cattle dung and water (50%:50%). The digester was then operated by continuously adding a 5-L mixture of cattle dung and water (50%:50%) every day for 1 month. Subsequently, the digester was operated for 1 month with an additional 5-L mixture of cabbage waste and water (50%:50%) for odd-numbered days and a mixture of cattle dung and water (50%:50%) for even-numbered days. The methane composition was higher (in the range of 41–78%) with only the cattle dung in the system. With the addition of cabbage waste, the methane composition became lower (in the range of 20–60%).

Enhancement of Nitrogen Retention in Cow Manure Composting with Biochar: An Investigation into Migration and Regulation Mechanisms

Context: Biochar can affect the storage and forms of nitrogen; thus, it may also play a role in altering the nitrogen cycle during the fermentation process of cow dung into organic fertilizer. Objective: To elucidate the mechanism and process of nitrogen transformation during the composting of cow manure with biochar, a comparative experiment was conducted. Method: This study investigates the use of biochar as a medium to enhance nitrogen storage during the aerobic composting of cow manure. The effectiveness was verified through a rapid composting experiment. Result and Conclusions: The results demonstrated that adding 5% biochar to the compost pile increased the total nitrogen content in manure by 12%. Specifically, the pyrrolic nitrogen in the composted cow manure increased from 38% to 44%, and the carbon-nitrogen ratio improved from 35% to 37%. Analysis of surface functional groups indicated that the C=O and C=C bonds in biochar played a key role in modifying nitrogen storage. Microbial analysis showed that biochar could significantly enhance the regional competitiveness of microorganisms, such as Cellvibrio, thereby boosting the expression of functional genes involved in the nitrification process, including amoABC, hao, and nxrAB. Therefore, adding 5% biochar not only enhances nitrogen storage in organic fertilizer but also changes the microbial population structure. Significance: This study carries substantial implications for the application of Biochar in the field, as well as for the development of microbial fertilizers based on cow manure.

UTILIZATION OF RICE STRAW WASTE INTO COMPOST FERTILIZER IN GAMPONG COT CUT, KUTA BARO SUB-DISTRICT ACEH BESAR DISTRICT

This Community Service (CS) activity aims to provide information to the community about the utilization of rice straw waste into compost in Gampong Cot Cut, Kuta Baro Sub-district, Aceh Besar District, by utilizing natural resources in the surrounding area so that it can improve the community's economy. Poliven lecturers and students to find out the potential and situation in Gampong Cot Cut Furthermore, planning activities that will be carried out and demonstrated to the community of Gampong Cot Cut. Then the second stage is providing direct explanations to the community about the utilization of rice straw waste in compost fertilizers. The stages of how to make it are: The available rice straw waste is chopped/reduced in size and then mixed with cow dung. Then the EM4 solution is added. The mixture is stirred evenly and tightly closed, and the fermentation process is carried out for 1 month. The CS activity carried out in Gampong Cot Cut, Ingin Jaya Sub-district, Aceh Besar District has been carried out very well and smoothly thanks to the assistance of several parties, namely LPPM Politeknik Indonesia Venezuela, support from the apparatus, and the community of Gampong Cot Cut. This CS activity is useful for developing the potential of the community to be more creative in creating new things, and the community is greatly helped by the demonstration of making rice straw compost.

Nitrogen Transformation Mechanisms and Compost Quality Assessment in Sustainable Mesophilic Aerobic Composting of Agricultural Waste

This study examines nitrogen transformation mechanisms and compost quality in mesophilic aerobic composting of wheat straw, utilizing cow manure as a co-substrate to promote sustainable agricultural waste management. Two composting systems were established: group A (control) and group B (10% cow manure addition by wet weight). The addition of cow manure accelerated early organic matter decomposition and increased total nitrogen retention in group B. Nitrogen losses occurred primarily via ammonia volatilization during the initial and final composting stages, while functional gene analysis revealed enhanced ammonification and nitrification in both systems. Microbial community analysis showed that cow manure addition promoted nitrogen-fixing bacteria in the early phase and fungi associated with complex organic degradation in later stages. These findings underscore the potential of cow manure to enhance compost maturity, improve nitrogen efficiency, and support the development of sustainable composting practices that contribute to resource conservation.

Dynamics and Insights into the Unique Ecological Guild of Fungi in Bacteria-Bioaugmented Anaerobic Digesters.

Anaerobic digesters host a variety of microorganisms, and they work together to produce biogas. While bacterial and archaeal communities have been well explored using molecular techniques, fungal community structures remain relatively understudied. The present study aims to investigate the dynamics and potential ecological functions of the predominant fungi in bacteria-bioaugmented anaerobic digesters. Eight different anaerobic digesters that contained chopped water hyacinth and cow dung as feedstock at 2% total solids were respectively inoculated with eight different bacterial strains and digested anaerobically in controlled conditions. The diversity and dynamics of the fungal community of the digesters before and after digestion were monitored using high-throughput sequencing of the fungal ITS2 sub-region of the ribosomal gene. The functional potential of the fungal community was predicted using ecological guild analysis. The dominant fungal phyla were (with relative abundance ≥1%) Ascomycota and Neocallimastigomycota. Ascomycota exhibited over 90% dominance in all treatments after anaerobic digestion (AD). Aspergillus sp. was consistently dominant across treatments during AD, while prominent anaerobic fungal genera Anaeromyces, Cyllamyces, and Caeomyces decreased. Ecological guild analysis at genus level showed that the majority of the identified fungi were saprophytes, and diversity indices indicated decreased richness and diversity after AD, suggesting a negative impact of AD on fungal communities in the anaerobic digesters. The multivariate structure of the fungal communities showed clustering of treatments with similar fungal taxa. The findings from this study provide insights into the fungal ecological guild of different bacteria-bioaugmented anaerobic digesters, highlighting their potentials in bacteria-augmented systems. Identification of an anaerobic fungal group within the phylum Ascomycota, beyond the well-known fungal phylum Neocallimastigomycota, offers a new perspective in optimizing the AD processes in specialized ecosystems.

PRODUCTION of AROMATIC BRAN USING LIQUID ORGANIC SUPPLEMENT of COW MANURE EFFECTS ON LACTIC ACID, pH, DRY MATTER LOSS and FLEIGH VALUE (NF)

This study aims to determine the effect of different doses of liquid organic supplements made cow manure added to rice bran to produce aromatic rice bran with the best values in terms of lactic acid, pH, dry matter loss, and Fleigh Value (NF). The research was conducted from May - June 2024 at the Ruminant Nutrition and Animal Feed Chemistry Laboratory, Faculty of Animal Science, Padjadjaran University. This experimental study employed a Completely Randomized Design with 3 treatments and 6 replications, P0 = 1 kilogram of bran + 300 grams of molasses, P1 = 1 kilogram of bran + 200 grams of molasses + 100 mL of SOC, and P2 = 1 kilogram of bran + 100 grams of molasses + 200 mL of SOC. Data analysis was using Analysis of Variance (ANOVA) and Duncan’s Multiple Range Test. The results showed that the use of cow manure SOC affected the pH, lactic acid content, and dry matter loss of aromatic rice bran, but did not affect the Fleigh Value (FV). The application of SOC with a dose of 100 grams of molasses + 200 mL SOC produced high lactic acid (21.12%), the lowest pH value (4.52), dry matter loss (8.21%), and a Fleigh value of (167.59%).

Comparative Analysis of Cow and Chicken Manure as Activators in Windrow Composting of Vegetable Waste

Comparative Analysis of Cow and Chicken Manure as Activators in Windrow Composting of Vegetable Waste

Biological management of stem rot of clusterbean under <i>in vitro </i>and <i>in vivo </i>conditions

Trichoderma harzianum and T. viride demonstrated significant inhibition of Sclerotium rolfsii mycelial growth, with 63.62 and 57.12 per cent inhibition, respectively. In contrast, bacterial bio-agents Pseudomonas fluorescens and Bacillus subtilis showed lower efficacy (42.31 and 38.56% inhibition, respectively). Garlic extract demonstrated the highest efficacy across all concentrations, with 66.67, 68.61 and 75.19 per cent inhibition at 5, 10 and 15% concentrations, respectively. Panchgavya, a cow product, showed promising results, with 34.81, 53.06, and 74.96 per cent inhibition at 5, 10, and 15% concentrations, respectively. Treatment T3 [Seed treatment with (T. harzianum + P. fluorescens) @ (5 g + 5 g) kg-1 + Soil application of (T. harzianum + P. fluorescens) @ (5 kg + 5 kg) ha-1] consistently emerged as the most effective, showing high disease control and low incidence rates with highest seed and straw yield. Combinations of bio-agents and bio-products exhibited superior disease control, with cow urine and cow dung-based treatments showing promise for organic disease management in clusterbean cultivation. Treatment T10 [Seed treatment with cow dung + Foliar application of Buttermilk] was least effective and consistently yielded the minimum seed and straw across all treatments.

Sheep Manure-Tail Vegetable-Corn Straw Co-Composting Improved the Yield and Quality of Mini Chinese Cabbage.

In order to fully utilize the resources of agricultural waste in Gansu Province's semi-arid area. Local commercial organic fertilizer (ST1) was selected as the control, and four kinds of planting and breeding waste composts (PBCs) were designed with sheep manure (SM), cow manure (CM), tail vegetable (TV), mushroom residue (MR), and corn straw (CS) to study the effects of the different PBC formulations on the yield and quality of mini Chinese cabbage. In contrast to local commercial organic fertilizer, the STS (SM:TV:CS = 6:3:1) treatment increased the economic yield by 5.56%. Additionally, STS also significantly increased the VC content of mini Chinese cabbage, increased the organic acid by 14.66%, increased the free amino acid by 38.98%, and the nitrate concentration was significantly reduced by 41.05%. Meanwhile, the STS formula also increased the concentrations of polyphenols and essential amino acids of mini Chinese cabbage and also had excellent performance in volatile compounds. As a result, the STS formula can make full use of local planting and breeding waste resources and produce high yield and high quality of local mini Chinese cabbage. The study provided a theoretical foundation and technical guidance for screening suitable local compost formulas, as well as for the achievement of high-yield and high-quality mini Chinese cabbage production in the semi-arid areas of central Gansu province.

In-vitro study of hybrid silver nanoparticles with humic acid extracted from cow dung against pathogens.

Recently, researchers have used silver nanoparticles (AgNPs) coupled with humic acid (HA) as antimicrobial agents. Herein, AgNPs were prepared and coupled with humic acid for their antimicrobial activities. The as-prepared AgNPs coupled with humic acid (HA) were characterized by an atomic force microscope (AFM), X-ray powder diffraction (XRD), zeta potential, zeta sizer, Fourier-transform infrared (FT-IR) spectroscopy, and UV-VIS spectrophotometer. Moreover, human plasma, varied salt concentrations, and pH levels were used for stability confirmation using a UV-VIS spectrophotometer. The antibacterial activities and minimal bactericidal concentration (MBC) of coupled AgNPs were determined by disk diffusion and broth dilution methods, respectively, against identified Staphylococcus aureus, Streptococcus pyogene, Pseudomonas aeruginosa, and Escherichia coli, which are extracted from cow dung. AgNPs' peak in the UV-Vis spectral range showed maximal absorption at 415nm. The coupled AgNPs displayed their distinctive peak under all circumstances, demonstrating their stability. The FT-IR displayed functional groups such as hydroxyl, carboxylic acids, carbonyl, ester, and ether groups. The particles were face-centered cubic (FCC) in structure, according to the XRD. Moreover, particles had a spherical shape, high negative zeta potential, and were polydisperse in nature, with an average size of 25.43nm. The minimal bactericidal concentration (MBC) of AgNPs was found to be 2.5mg/mL, and the MBC of AgNPs/HA was found to be 5mg/mL. The result indicated that the as-synthesizedAgNPs/HA are more effective in inhibiting all the studied microorganisms, which can be attributed to the therapeutic use of nanoparticles coated with humic acids.

Improvement of Iron and β-Carotene Bioaccessibility in Complementary Foods: Biofortification of Local Crops With Organic Residual Products and Microorganisms.

Micronutrient deficiencies remain a great public health challenge worldwide with iron, zinc, and vitamin A being the most problematic. It has been shown that biofortification through agronomic strategies can increase their micronutrient content, but data on the bioavailability remain limited. In Senegal, consumption of cereals and legumes is high, and orange-fleshed sweet potato (OFSP), rich in β-carotene, has been introduced a decade ago. The objective of the present work was to assess the bioaccessibility of iron, zinc, and β-carotene in local complementary foods prepared with millet, cowpea, and OFSP alone or in combination, produced using different agronomic biofortification strategies. Organic residual products were used alone or in combination with microorganisms to produce the abovementioned crops that were used to prepare the complementary foods. Static invitro digestion was performed to assess the bioaccessibility of the micronutrients, according to a harmonized protocol. The two organic residual products had different effect, as the cow dung alone was inefficient to increase iron and zinc contents as well as their bioaccessibility in millet porridges. However, the use of poultry litter alone or in combination with microorganisms increased iron bioaccessibility in cooked cowpea (27%-29%) compared to the non-biofortified counterpart (9%). Surprisingly, bioaccessible β-carotene was significantly higher (4.1%) in sample of mashed OFSP biofortified with the combination of the different agronomic strategies than in the others (1.4%-2.5%). Portions (150 g) of porridge prepared from the three biofortified crops would cover up to 100% of the daily vitamin A requirements of children aged 6-23 months. The use of a combination the most promising varieties of crops, together with the agronomic strategies, would be a complementary approach to sustainability limit micronutrient deficiencies in a context of monotonous diets.

Impact of anaerobic co‑digestion of ryegrass (RG) and cow manure (CM) on methane production and Kinetic analysis

Impact of anaerobic co‑digestion of ryegrass (RG) and cow manure (CM) on methane production and Kinetic analysis

Advanced anaerobic co-digestion of hydrothermally pretreated wheat straw: Process performance, techno-economic and life cycle assessment.

Hydrothermal and thermal-alkali pretreatment potential was investigated to enhance agro-wastes' anaerobic co-digestion (AcoD). The techno-economic (TEA) and life cycle assessment (LCA) of biogas upgrading (BioCNG) and energy generation via combined heat and power (CHP) processes for energy utilization were carried out to realize the environmental impacts and cost-effectiveness of the studied processes. Three AcoD conditions of untreated, hydrothermally (150°C, 60min) and thermal-alkali pretreated (1% NaOH, 150°C- 60min) wheat straw (WS) with food waste and cow manure were studied in semi-continuous mode for 340 days under variable organic loading rates (OLR, 1.25-3.75 gVS/L.d). At an OLR of 1.67 gVS/L.d and 45 days HRT, the methane yield and volatile solids removal in control digester were 231 mL/gVS and 39.7%, and in thermal-alkali pretreated digester were 302 mL/gVS and 53.3%, presenting an increase of 30% and 34% over control, respectively. The LCA and TEA of all three processes under 45 days of HRT operations were carried out. The environmental performance evaluation across various scenarios indicated that integrating pretreatment with the combined heat and power (CHP) process significantly lowered the global warming potential (GWP), outperforming the BioCNG process. In particular, hydrothermal pretreatment made the largest contribution to the reduction in GWP, achieving a value of -0.1935kg CO2-equivalent, primarily due to energy generation from the CHP process. In comparison, the BioCNG process recorded a GWP of -0.0377kg CO2-equivalent. This result demonstrates that the CHP process led to an 81% greater reduction in GWP than the BioCNG process. While the BioCNG process surpassed CHP in terms of economic performance, the hydrothermal pretreatment scenario proved to be financially the most advantageous, with a net present value (NPV) of $10.16 million, an internal rate of return (IRR) of 13%, and a shorter payback period (PBP) of 14 years.

How does the chemical composition of dung affect nitrous oxide and methane emissions in pasture soils?

There is an important gap in how variations in herbivore dung composition affect GHG emissions on pastures, especially due to differences in dry matter (DM) and nitrogen contents. Oversimplifications can compromise the accuracy of mitigation strategies. This study aims to address this gap by investigating how the chemical composition of dung from different species influences GHG emissions in pasture systems. The results showed that drier dung led to higher cumulative N₂O emissions. The highest emissions were observed from goat at 9.47 mg N-N₂O g⁻1 dry soil, followed by sheep at 5.95 mg N-N₂O g⁻1 dry soil, beef cattle at 5.44 mg N₂O g⁻1 dry soil, dairy cattle at 2.67 mg N₂O g⁻1 dry soil, and horse at 0.83 mg N₂O g⁻1 dry soil. It was observed that higher dung moisture content generally corresponded to increased CH₄ emissions, except for horse dung. The highest cumulative CH₄ emission was for dairy cattle dung (8.29 mg C-CH₄ g⁻1 dry soil), followed by beef cattle (3.89 mg C-CH₄ g⁻1 dry soil), sheep (2.32 mg C-CH₄ g⁻1 dry soil), goats (1.89 mg C-CH₄ g⁻1 dry soil), and horses (1.66 mg C-CH₄ g⁻1 dry soil). Principal Component Analysis illustrated that PC1, named as diet quality, explained 61.9% of the variance, was positively correlated with N₂O and negatively correlated with fiber content and C/N ratio, while PC2, named as acetrophic and hydrogenotrophic methanogenesis, explained 19.6% of the variance, linking VS to reduced CH₄ emissions. This study establishes relationships between manure chemical composition and GHG emissions, filling a fundamental knowledge gap and supporting the development of cause-and-effect models.