Search Results (81)

Biodegradation is a green and efficient method for lignin depolymerization and conversion. In order to screen potential bacterial strains for efficient lignin degradation, composts of cow dung and wheat straw were prepared, and the dynamic changes in the predicted bacterial community structure and function in different periods of the composts were investigated. Then, bacteria with an efficient lignin degradation ability were finally screened out from the compost samples. Based on the monitoring results of the physicochemical indexes of the composting process, it was found that the temperature and pH of the compost firstly increased and then decreased with the extension of time, and the water content and C/N gradually decreased. High-throughput sequencing of compost samples from the initial (DA), high-temperature (DB), and cooling (DC) periods revealed that the number of OTUs increased sharply then stabilized around 2000, and the alpha diversity of the bacterial community decreased firstly and then increased. The predominant phyla identified included Proteobacteria, Firmicutes, Chloroflexi, and Bacteroidetes, determined by the relative abundance of beta-diversity-associated species. Functional gene analysis conducted using Tax4Fun revealed that the genes were primarily categorized into Metabolism, Genetic Information Processing, Environmental Information Processing, and Cellular Processes. Based on the decolorization of aniline blue and the degradation efficiency of alkali lignin, eight bacterial strains were isolated from compost samples at the three stages. Cupriavidus sp. F1 showed the highest degradation of alkali lignin with 66.01%. Cupriavidus sp. D8 showed the highest lignin degradation potential with all three enzyme activities significantly higher than the other strains. The results provide a strategy for the lignin degradation and utilization of biomass resources. Full article

Labile organic carbon (OC), a dynamic component of soil organic carbon (SOC), is essential for improving soil health, fertility, and crop productivity, particularly when organic and inorganic amendments are combined. However, limited research exists on the best amendment strategies for restoring degraded gleyic solonetz soggy sodic (GSSS) soils in West Africa’s coastal zones. A three-year field study (2017–2019) assessed the effects of various combinations of organic (mature or composted cow dung, with or without biochar) and inorganic inputs on soil organic carbon fractions, total carbon stocks, and the Carbon Management Index (CMI) in GSSS soils of Sege, Ada West District, Ghana. The results showed that organic and inorganic combinations outperformed the sole inorganic NPK treatment and the control, particularly in the topsoil. Composted cow dung with mineral fertilizer (CCfert) was especially effective, significantly increasing labile OC, SOC stock, and CMI by 35.3%, 140.5%, and 26% in the topsoil compared to the control and by 28%, 77.8%, and 4.3% compared to NPK alone. In the subsoil, mature cow dung-based treatments performed better. These findings highlight the potential of integrated organic and inorganic strategies, especially those based on composted manure, to rehabilitate degraded sodic soils, build carbon stocks, and improve soil quality for sustainable agriculture in coastal West Africa. 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

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. Full article

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. 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

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. Full article

Mastitis represents a significant challenge for dairy farming, resulting in economic losses and environmental impacts. This study assesses a model for the evaluation of the impact of mastitis on dairy productivity and Global Warming Potential (GWP) under diverse management scenarios. The model considers a range of factors, including bedding materials, milking systems, health surveillance, and overcrowding. The results of the simulation demonstrate that effective management, encompassing the utilization of sand bedding, and the presence of an annual herd health monitoring plan have the potential to reduce the prevalence of mastitis and enhance milk yield by up to 10% in milking parlors and 7% in automatic milking systems. At the herd level, the GWP ranged from 1.37 to 1.78 kg CO₂eq/kg Fat- and Protein-Corrected Milk (FPCM), with the use of sand bedding resulting in a 14% reduction in GWP, while the utilization of non-composted manure-based materials led to an increase of 12%. The occurrence of overcrowding and a lack of adequate cleanliness in resting areas were found to have a markedly detrimental impact on both productivity and the environmental performance of cows. These findings illustrate the dual benefits of enhanced mastitis management, namely improved milk production and reduced environmental impact. They offer valuable insights for farmers and policymakers alike. Full article

The compost-bedded pack (CBP) system offers a sustainable solution for dairy farms by enhancing cow welfare and health while promoting environmental sustainability and improving manure management for agricultural reuse. This study aimed to evaluate the reduction in manure treatment required for agricultural use by analyzing manure excretion patterns in lactating cows. We compared seven Holstein and six Holstein × Gyr cows, divided into two CBP groups, and monitored their feces and urine behaviors over a 48 h period. Manure excretion was recorded across four farm areas: (1) feeding area, (2) resting area (composted bed), (3) path to the milking parlor, and (4) milking parlor. Both breeds predominantly excreted feces (45.03%) and urine (54.18%) in the resting area, which facilitated composting directly in the bedding. This resulted in a significant reduction in nitrogen requiring treatment, averaging 76.8–85.3 g per cow per day, accounting for 44–49% of total nitrogen excretion. The CBP system demonstrated its effectiveness in reducing environmental impact by minimizing nitrogen loss through volatilization and leaching, while also enhancing nutrient recycle in agriculture. These findings emphasize the CBP system’s role in foresting sustainable dairy farming and environmentally friendly agricultural practices. Full article

Bone meal has been used as economic and effective additive for heavy metals (HMs) pollution remediation due to the distinct components and structures that enable their favorable properties, such as its low cost, high adsorption capacity, acid-base adjustability, and ion-exchange capability. However, no attempt has been made to establish whether cow bone could promote the passivation of HMs and the removal of metal resistance genes (MRGs) and antibiotics resistance genes (ARGs) during the composting process. Two sizes of cow bone (meal (T2) and granule (T3)) were added to investigate their effects on humification, HMs passivation and the abundance of ARGs and MRGs during swine manure composting. Excitation-emission matrix (EEM)-parallel factor analysis showed that the percentage of maximum fluorescence intensity of humic-like substances were higher in T2 (91.82%) than in T3 (88.46%), implying that T2 could promote the humification process compared to T3. In comparison with control (T1), the addition of T2 and T3 could promote the change of exchangeable Cu and reducible Cu into oxidizable Cu, thus reducing the mobility factors (MF) of Cu in T2 and T3 treatments by 10.48% and 6.98%, respectively. In addition, T2 and T3 could increase exchangeable Zn into reducible Zn and oxidizable Zn, thereby reducing the MF of Zn in T2 and T3 treatments by 18.80% and 2.0%, respectively. Quantitative Real-time PCR (qPCR) analysis revealed that the total abundances of MRGs were decreased by 100% in T2 and T3 treatments, and T2 decreased the total relative abundance of ARGs. Furthermore, the relative abundance of ARGs and MRGs had significantly correlated with intI1 and bio-available of Cu and Zn, which was triggered by selective pressure of HMs and horizontal gene transfer. The present study suggested that cow bone meal as additives can be a feasible approach to promote the passivation of HMs and enhance the removal of MGRs and ARGs by decreasing horizontal gene transfer and selective pressure by bioavailable HMs. Full article

Azolla is a substitute compost that has the potential to enhance nutrient cycling in agricultural systems for sustainable development. In this study, four experiments were conducted to compare the Department of Agriculture (DOA, Thailand)’s methodology for determining the suitable type and rate of animal manure and the optimal light intensity for the growth and yield of Azolla (Azolla microphylla). The results revealed that applying 100% pig manure gave the highest yield of Azolla compared to the other manures. However, there was no discernible (p > 0.05) difference in yield across the various doses (20.16, 30.16, and 40.16 gN m⁻²) of pig manure treatments, for which the minimal pig manure dosage of 20.16 gN m⁻² was chosen. For further experimentation in the optimal light intensity, the 40% shading gave the highest yield of Azolla compared to no shading or 20 and 60% shading (p ≤ 0.01). When compared with the DOA Thailand methodology (1.27 kg m⁻² of cow manure and covered with a size 32 mesh net), the findings indicated that the modified method (20.16 gN m⁻² of pig manure + 40% shading) gave a 16% greater Azolla yield than that under the DOA Thailand methodology. The current finding method can produce a monthly fresh biomass of A. microphylla of 40.7 t ha⁻¹ year⁻¹ with higher contents of total N (4.92%) and lower C:N ratio (≤10:1) that could release minerals relatively rapidly. Its use can be encouraged by farmers to produce their own ecofriendly biofertilizer or soil amendment for sustainable agriculture. Full article

Concentrations of specific secondary metabolites can be higher in organically grown crops. This may be linked to organic nitrogen (N) nutrition that provides a gradual supply of N to crops over the growing season. This study examined whether organic N nutrition influenced the concentration of glucosinolates in broccoli crops. Nitrogen release patterns were determined from three synthetic (Rustica, 12% N; calcium nitrate, 15.5% N; urea, 46% N) and two organic fertilizers in an incubation experiment. Broccoli seedlings were then grown in two N dose response pot trials with different N source or application timing treatments to investigate growth and glucosinolate responses. Synthetic fertilizers released 84 to 89% of total N after 28 days, while chicken manure pellets and composted cow manure had only released 52% and 13% of total N, respectively, after 91 days. Broccoli yield and N content were generally higher in synthetic fertilizer treatments. Glucosinolate concentrations were generally higher in the synthetic fertilizer treatments, and only sinigrin and glucoiberin concentrations in the 800 kg ha⁻¹ N application rate of organic fertilizer matched those in the corresponding synthetic fertilizer treatment. Broccoli head weight was reduced when N was applied fortnightly compared to basal and weekly N applications, but glucosinolate concentrations were not significantly different. Overall, there was no evidence that organic (chicken manure) N nutrition, or the rate of N supply to broccoli plants, affect glucosinolate concentrations. Full article

Composting is a common method for managing organic waste and creating nutrient-rich soil amendments. Recently, biochar, a carbon-rich material from biomass pyrolysis, has been noted for potentially improving composting. This study examines the impact of adding biochar to compost made from cow manure and kitchen waste through a controlled lab experiment. The treatments were labeled as CMX (cow manure), KWX (kitchen waste), and CMKWX (both) with X being the percentage of CM, KW, and CMKW minus that of biochar in the mixture. Key parameters such as temperature (T), pH, and electric conductivity (EC) were tracked during the composting processes, and the final composts were analyzed for total nitrogen (N), available nitrogen (AN), total phosphorus (TP), available phosphorus (AP), total potassium (TK), organic carbon (OC), calcium (Ca²⁺), magnesium (Mg²⁺), and organic matter (OM). The results showed that adding less than 10% biochar influenced composting positively. Specifically, 5% biochar amendment led to higher thermophilic temperatures (45–57 °C) and stable pH levels (6.3–8.7) compared to controls. However, biochar did not significantly enhance EC, which peaked at 1.78 dS/m in both the control and 5% biochar treatments. Nutrient analysis revealed that biochar increased Ca²⁺ (13.62 meq/g) and Mg²⁺ (5.73 meq/g) retention in CM composts (CM85 and CM100). The highest OM content was 16.84% in CM90, while the lowest was 3.81% in CM95. Higher OM negatively affected TN, with CM treatments having more OM and KW treatments having more TN. TP and TK were higher in control treatments without biochar. This study highlights the benefits of integrating biochar with organic waste for enhancing compost nutrient profiles and soil fertility. It was observed that the more diverse the compost feedstock, i.e., CMKW, the higher the nutrient content for treatments containing less than 10% biochar. Full article

Anaerobic digestion (AD) is a promising biowaste valorization technology for sustainable energy, circular economy, local energy community growth, and supporting local authorities’ environmental goals. This paper presents a systematic review meta-analysis methodology for biomethane estimation, using over 600 values of volatile solids (VS) content and biochemical methane potential (BMP) of six different waste streams, collected from 240 scientific studies. The waste streams include cow manure (CM), sheep/goat manure (SGM), wheat straw (WS), household waste (HW), organic fraction of municipal solid waste (OFMSW), and sewage sludge (SS). The statistical analysis showed a mean VS content of 11.9% (CM), 37.3% (SGM), 83.1% (WS), 20.8% (HW), 19.4% (OFMSW), and 10.6% (SS), with BMP values of 204.6, 184.1, 305.1, 361.7, 308.3, and 273.1 L CH₄/kg VS, respectively. The case study of Kozani, Greece, demonstrated the methodology’s applicability, revealing a potential annual CH₄ production of 15,429,102 m³ (corresponding to 551 TJ of energy), with SGM, WS, and CM as key substrates. Kozani, aiming for climate neutrality by 2030, currently employs conventional waste management, like composting, while many local business residual streams remain unused. The proposed model facilitates the design and implementation of AD units for a sustainable, climate-neutral future. Full article

In the Vietnamese Mekong Delta, soil quality and crop yield are steadily declining under rice monocultures with three crops per year. The objective of this study was to evaluate the medium-term effects of rotating rice with upland crops and adding organic amendments on rice yield, and to relate this to soil quality. A field trial with split-plot design including two factors and three replicates was carried out from 2017 to 2020, over the course of nine consecutive cropping seasons. Crop rotations and organic amendments were applied as main-plot and subplot factors, respectively. The rotations were (1) rice–rice–rice (R–R–R), (2) soybean–rice–rice (So–R–R), and (3) sesame–rice–rice (Se–R–R), while organic amendment treatments included (i) no amendment (NO-AM), (ii) compost of rice straw and cow manure (RS+CM), and (iii) sugarcane compost (SGC); the composts were applied at a rate of 2.0 t ha⁻¹. The rotation cycle started with the so-called spring–summer (SS) season, followed by the summer–autumn (SA) season and ending with the winter–spring (WS) season. Rice yield significantly (p < 0.05) increased under organic amendments after nine growing seasons (2019–2020 WS), with an increment of 5.1% for RS+CM (7.07 ton/ha) and 6.1% for SGC (7.14 ton/ha). Contrary to our expectation, rotations with upland crops did not significantly increase rice yield. Rice yield significantly and positively correlated with an integrated soil quality index–SQI (r = 0.85) for the topsoil (0–15 cm), but not for the subsoil (15–30 cm). The increased availability of soil nutrients (Si and marginally also P) and improved soil physical properties probably induced by organic amendments, along with other soil properties under study, cumulatively attributed to enhanced rice yield. Repeated organic amendments thus becomes an effective management practice in improving soil quality under rice-based systems and could be applied to sustain rice yield in rice-producing regions with similar soil types and climatic conditions. Use of a SQI involving several soil quality indicators enables us to quantify the overall importance of soil fertility for rice yield versus other factors, and it provides an effective means of quantifying the integrated effect of improved management. Moreover, integrating a wide range of soil quality indicators in a SQI ensures its applicability across diverse settings, including different crop rotations and various soil types. Full article