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Objectives This study aims to assess the environmental impact of the composting process, which constitutes 75.3% of the domestic livestock manure recycling methods, and to determine the environmental impacts of methane and nitrous oxide, the major greenhouse gases in the livestock sector, as well as ammonia, a precursor to fine particulate matter that has recently become a social issue. The analysis will focus on the categories of climate change and fine particulate matter formation to identify the most significant factors impacting the environment. Methods This study applied the Life Cycle Assessment (LCA) methodology according to ISO 14040/14044 standards to evaluate the environmental impact of producing one bag (20kg) of livestock manure compost. The system boundary included the transportation of livestock manure and sawdust to the composting facility and the compost production process. The methodology applied for impact assessment was the ReCiPe 2016 v.1.1 Midpoint (H) method, which allows for a more global evaluation by utilizing worldwide average data. Results and Discussion The impact assessment of livestock manure compost production revealed that producing one bag contributes 2.667 kg CO2-eq. to climate change, with electricity consumption responsible for 68.95% of emissions. Carbon dioxide (CO2) is the dominant greenhouse gas, making up 84.37% of the total. Particulate matter formation is 0.037 kg PM2.5-eq., with 91.97% resulting from emissions during the composting process. Ammonia (NH3) is the main cause of particulate matter, accounting for 92.02% of emissions. Conclusion Based on the research, electricity consumption is the main factor affecting climate change in compost production, and ammonia is the primary cause of fine particulate matter. This study provides a case for evaluating the environmental impact of livestock manure composting and can serve as a foundational reference for developing policies and technologies to address climate change and fine particulate matter issues.

Open manure storage contributes to the release of ammonia (NH3) into the atmosphere. Tank floating covers represent an effective technique to reduce NH3 emissions and biochar has been gain attention as a floating cover and as manure additive. Nevertheless, the mechanisms involved in the process still need to be elucidated since they are influenced by the biochar specific properties, application methods and dose. This work aims to study: (i) the biochar adsorption performances in an NH3 aqueous solution under conditions relevant to manure storage and (ii) the effect of different biochar application methods and dosage on NH3 emissions from buffalo digestate storage. The results show that a 43% reduction in NH3 emissions can be achieved by using biochar as a floating cover of 2 cm rather than as an additive. Moreover, the results show that the biochar produced at 550 °C acts as an adsorbent material for both NH4+ and NH3, by being adsorbed on the biochar surface in the form of NH4+ after H+ abstraction from the acid groups. A minimum cover height of 2 cm is required to give compactness and provide an additional resistance to the gas transfer, which is even more relevant than the adsorption in reducing NH3 emissions. [ABSTRACT FROM AUTHOR]

This study delves into the innovative application of a novel bacterial and enzyme mixture alone or combined with aeration in mitigating emissions from pig slurry storage and explores their impacts on the methane (CH4), carbon dioxide (CO2), and ammonia (NH3) emissions from stored pig slurry. A dynamic chamber was used in this research to assess the efficacy of the treatments. Biological additives (HIPO-PURÍN) of specific microbial strains were tested (a mixture ofof Bacillus subtilis, Bacillus megaterium, Bacillus licheniformis, Bacillus amyloliquefacien, and Bacillus thuringiensis) alone and combined with an aeration system (OXI-FUCH). Controlled experiments simulated storage conditions, where emissions of ammonia, methane, and carbon dioxide were measured. By analyzing the results statistically, the treatment with HIPO-PURÍN demonstrated a significant reduction in CH4 emissions by 67% and CO2 emissions by 60% with the use of biological additives, which was increased to 99% and 87%, respectively, when combined with OXI-FUCH aeration, compared to untreated slurry. Ammonia emissions were substantially reduced by 90% with biological additives alone and by 76% when combined with aeration. The study was driven by the need to develop sustainable solutions for livestock waste management, particularly in reducing emissions from pig slurry. It introduces techniques that significantly lower greenhouse gases, aligning with circular economy goals and setting a new standard for sustainable agriculture. Furthermore, there is a need to validate that farmers can independently manage pig slurry using simple and effective treatments techniques with profound environmental benefits, encouraging broader adoption of climate-conscious practices. [ABSTRACT FROM AUTHOR]

Greenhouse gas (GHG) emissions, ammonia (NH3) emissions, eutrophication potential (EP), use of fossil energy, direct land, and blue water of organic dairy farms are evaluated in the Mideast, Northeast, Southeast, and Mountain regions of the US. Eighteen archetypical organic dairy farms are modeled with GHGs per kg fat and protein corrected milk (FPCM) ranging between 0.83 and 1.45 kg CO2-eq with and 0.93 to 1.59 kg CO2-eq without carbon sequestration. Enteric methane (CH4) is the major contributor (42–58%) of farm GHGs, followed by CH4 from manure (15–27%), energy use (8–18%), and material inputs (3–24%). Enteric CH4 is affected by feed efficiency and milk production, manure CH4 by the type of manure handled and stored, and GHGs from energy by the content of fossil-fuel sources in the electricity grid mix. Manure is the major source of NH3 emissions ranging from 8.2 to 24.3 g/kg FPCM. Alternative GHG mitigation strategies show potential reductions of up to 23 and 51% for individual and combined strategies, respectively. While enteric CH4 is the greatest GHG contributor, manure management has greater GHG mitigation potential. The choice of CH4 predictive equations, N2O emission factors, allocation, and functional units could increase GHGs up to 43% in the evaluated organic dairy farms.

Abstract Ammonia is emerging as a viable alternative to fossil fuels in combustion systems, aiding in the reduction of carbon emissions. However, its use faces challenges, including NOx emissions and low flame speed. Innovative approaches and technologies have significantly advanced the development and implementation of ammonia as a zero-carbon fuel. This review explores current advancements in using ammonia as a fuel substitute, highlighting the complexities that various systems need to overcome before reaching full commercial maturity in support of practical decarbonising global strategies. Different from other reviews, this article incorporates insights of various industrial partners currently working towards green ammonia technologies. The work further addresses fundamental complexities of ammonia combustion, crucial for its practical and industrial implementation in various types of equipment.

Ammonia is emerging as a viable alternative to fossil fuels in combustion systems, aiding in the reduction of carbon emissions. However, its use faces challenges, including NOx emissions and low flame speed. Innovative approaches and technologies have significantly advanced the development and implementation of ammonia as a zero-carbon fuel. This review explores current advancements in using ammonia as a fuel substitute, highlighting the complexities that various systems need to overcome before reaching full commercial maturity in support of practical decarbonising global strategies. Different from other reviews, this article incorporates insights of various industrial partners currently working towards green ammonia technologies. The work further addresses fundamental complexities of ammonia combustion, crucial for its practical and industrial implementation in various types of equipment. [ABSTRACT FROM AUTHOR]

Hyperthermophilic bio-drying has stronger organic matter degradation and drying ability than the conventional bio-drying. However, ammonia emissions during the hyperthermophilic bio-drying are significantly higher than those during the conventional bio-drying process due to the higher temperature and pH value. Phosphate has been reported to reduce ammonia emissions during composting. Meanwhile, both the degradation of organic matter and the addition of phosphate buffer can promote the formation of EPS. EPS exhibits strong passivation and adsorption properties for heavy metals and organic pollutants, thus positively impacting the control of pollution in bio-drying products. Furthermore, the formation of EPS and the risk of the migration of heavy metals during hyperthermophilic bio-drying have not been reported. According to the results, compared to conventional bio-drying, the hyperthermophilic bio-drying significantly increased the yield of EPS and generated more active groups, reducing the migration risk of Cu, Zn, Cr, Pb, Cd, As, and Ni. The comprehensive potential ecological risk was reduced by 29.71%, which was higher than the reduction achieved by conventional bio-drying (13.81%). The addition of phosphate significantly reduced the ammonia emissions from the hyperthermophilic bio-drying and retained more nitrogen. Meanwhile, it promoted the formation of EPS and the enrichment of active groups, further reducing the migration risk of heavy metals. Moreover, the addition of phosphate buffer further reduced the comprehensive potential ecological risk of the products obtained from. [ABSTRACT FROM AUTHOR]

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ABSTRACT: Almost 60% of all ammonia (NH3) emissions are from livestock manure. Understanding the sources and magnitude of NH3 emissions from manure systems is critical to implement mitigation strategies. This study models 13 archetypical conventional (5 farms), organic (5 farms), and grazing (3 farms) dairy farms to estimate NH3 emissions from manure at the barn, storage, and after land application. Mitigation practices related to management of the herd, crop production, and manure are subsequently modeled to quantify the change in NH3 emissions from manure by comparing archetypical practices with these alternative practices. A mass balance of nutrients is also conducted. Emissions per tonne of excreted manure for the manure system (barn, storage, and land application) range from 3.0 to 4.4 g of NH3 for conventional farms, 3.5 to 4.4 g of NH3 for organic farms, and 3.4 to 3.9 g of NH3 for grazing farms. For all farm types, storage and land application are the main sources of NH3 emissions from manure. In general, solid manures have higher emission intensities due to higher pH during storage (pH = 7.4 for liquid, 7.8 for slurry, and 8.5 for solid manure) and lower infiltration rates after land application when compared with slurry and liquid manures. The most effective management practices to reduce NH3 emissions from manure systems are combining solid-liquid separation with manure injection (up to 49% reduction in NH3 emissions), followed by injection alone, and reducing crude protein in the dairy ration, especially in organic and grazing farms that have grazing and forages as the main component of the dairy ration. This study also shows that the intensity of NH3 emissions from manure depends significantly on the functional unit and presents results per manure excreted, total solids in excreted manure, animal units, and fat- and protein-corrected milk.

Up to 58% of NH3 emissions can be reduced through the use of the urease inhibitor Atmowell® in cattle farming. Automated manure scraper and drag hose systems should be used to apply urease inhibitors (UIs) to stable floors. Proof of safe use is also needed. A risk assessment of the urease inhibitor PPDA was conducted utilising estimated and calculated exposure data along with established and verified model calculation tools. Risk assessment models can be improved using measured dermal exposure data. The fluorescent dye pyranine and a Tyvek® collector were used to measure exposure. Tyvek® was attached to a lifelike cow dummy. Regarding the drag hose system, two worst-case scenarios were considered: over the cow and passing the cow. Regarding the robot application system, a 0 m frontal scenario was considered. The over the cow scenario exhibited the highest dermal exposure, with 1.5 mg of PPDA/cow per application run. The robot scenario exhibited the smallest amount, with 0.8 mg of PPDA/cow per application run. The risk of using PPDA was already excluded by model calculation tools in a risk assessment. Compared with the estimated and calculated dermal exposure values, the measured dermal exposure levels were reduced by a factor of two to six. [ABSTRACT FROM AUTHOR]

Different strategies have been tested to reduce nitrogen losses and gaseous ammonia emissions during composting. Among them, the supplementation of the composting mixture with biochar has shown good results and has attracted increasing attention from researchers over more than a decade. In order to capitalise on the numerous existing results, the relevant data from the literature were subjected to descriptive statistics and to a Pearson parametric correlation analysis. The statistical treatment of the literature data confirms that biochar reduces nitrogen losses, ammonia and nitrous oxide emissions during composting with highly variable performance (respectively reduction of 26.2% ± 16.7%; 46% ± 26.4%; 46.1% ± 31.1%). Statistically significant correlations were identified between N losses and biochar properties. However, the PCA results show that only 44.75% of the variability in the N loss reduction dataset and 57.8% of the ammonia emission reduction dataset were explained by the main variables available in the literature. This suggests that much of the variability in biochar performance remains unexplained. The large number of variables involved in the process and the lack of fine characterisation of biochar in most studies explain the remaining difficulty in fully understanding the complex action of biochar in composting and opens up prospects for further research. [ABSTRACT FROM AUTHOR]

Almost 60% of all ammonia (NH 3) emissions are from livestock manure. Understanding the sources and magnitude of NH 3 emissions from manure systems is critical to implement mitigation strategies. This study models 13 archetypical conventional (5 farms), organic (5 farms), and grazing (3 farms) dairy farms to estimate NH 3 emissions from manure at the barn, storage, and after land application. Mitigation practices related to management of the herd, crop production, and manure are subsequently modeled to quantify the change in NH 3 emissions from manure by comparing archetypical practices with these alternative practices. A mass balance of nutrients is also conducted. Emissions per tonne of excreted manure for the manure system (barn, storage, and land application) range from 3.0 to 4.4 g of NH 3 for conventional farms, 3.5 to 4.4 g of NH 3 for organic farms, and 3.4 to 3.9 g of NH 3 for grazing farms. For all farm types, storage and land application are the main sources of NH 3 emissions from manure. In general, solid manures have higher emission intensities due to higher pH during storage (pH = 7.4 for liquid, 7.8 for slurry, and 8.5 for solid manure) and lower infiltration rates after land application when compared with slurry and liquid manures. The most effective management practices to reduce NH 3 emissions from manure systems are combining solid-liquid separation with manure injection (up to 49% reduction in NH 3 emissions), followed by injection alone, and reducing crude protein in the dairy ration, especially in organic and grazing farms that have grazing and forages as the main component of the dairy ration. This study also shows that the intensity of NH 3 emissions from manure depends significantly on the functional unit and presents results per manure excreted, total solids in excreted manure, animal units, and fat- and protein-corrected milk. [Display omitted] [ABSTRACT FROM AUTHOR]

Objective In our previous study, we observed that the addition of waste cooking oil (WCO) reduced ammonia (NH3) emissions during laboratory-scale composting of dairy cattle manure under low-aeration condition. Therefore, this study aimed to evaluate the effect of addition of WCO on NH3 emissions reduction during pilot-scale composting of dairy cattle manure, which is close to the conditions of practical composting treatment. Methods Composting tests were conducted using pilot-scale composting facilities (1.8 m3 of capacity). The composting mixtures were prepared from manure, sawdust, and WCO. Two treatments were set: without WCO (Control) and with WCO added to 3 wt% of manure (WCO3). Composting was conducted under continuous aeration at 40 L/min, corresponding to 22.2 L/(min·m3) of the mixture at the start of composting. The changes in temperatures, NH3 concentrations in the exhaust gases, and contents of the composted mixtures were analyzed. Based on these analysis results, the effect of WCO addition on NH3 emissions and nitrogen loss during composting was evaluated. Results During composting, the temperature increase of the composting mixture became higher, and the decreases of weight and water content of the mixture became larger in WCO3 than in Control. In the decrease of weight, and the residual weight and water content of the mixture, significant differences (p

Open manure storage contributes to the release of ammonia (NH3) into the atmosphere. Tank floating covers represent an effective technique to reduce NH3 emissions and biochar has been gain attention as a floating cover and as manure additive. Nevertheless, the mechanisms involved in the process still need to be elucidated since they are influenced by the biochar specific properties, application methods and dose. This work aims to study: (i) the biochar adsorption performances in an NH3 aqueous solution under conditions relevant to manure storage and (ii) the effect of different biochar application methods and dosage on NH3 emissions from buffalo digestate storage. The results show that a 43% reduction in NH3 emissions can be achieved by using biochar as a floating cover of 2 cm rather than as an additive. Moreover, the results show that the biochar produced at 550 °C acts as an adsorbent material for both NH4+ and NH3, by being adsorbed on the biochar surface in the form of NH4+ after H+ abstraction from the acid groups. A minimum cover height of 2 cm is required to give compactness and provide an additional resistance to the gas transfer, which is even more relevant than the adsorption in reducing NH3 emissions.

Reducing ammonia emissions is one of the great environmental challenges of the agricultural sector and is by far the most important emitter of this air pollutant. This study analyses maize cultivation with an emerging organic fertilisation management technique, i.e., pre-seeding injection, followed by side-dressing fertigation, through a life cycle assessment approach at the farm gate with the aim of evaluating its influence on crop production as a whole, with a focus on nitrogen emissions during field application. This was done on two sample farms, one of which was fertigated using drip irrigation and the other by pivot irrigation. Each farm was then compared with a reference scenario in which traditional organic fertilisation and irrigation were used. The inventory data consist of measurements made during field trials, data collected from questionnaires to farmers and modelling estimates. The optimised management of the digestate led to important reductions in the impacts affected by ammonia emissions; acidification was reduced by 68% and 80%. Relevant mitigations were achieved for eutrophication and particulate matter formation and for the carbon footprint (12–14%). A trade-off was identified in the increased impact on the consumption of fossil and mineral resources (13–17%) due to the construction and operation of a vibrating screen operating the filtration of the liquid fraction of digestate. In conclusion, the results indicate the general benefits of improved organic fertilisation management as a whole. Future efforts should be aimed at energy and construction efficiency measures of digestate treatments. [Display omitted] • Ammonia (NH 3) emissions are responsible of environmental impacts and health concerns. • The environmental benefits related to fertigation with digestate of maize were evaluated by LCA. • Field trials on maize field with pivot and drip irrigation and fertigation were carried out. • Fertigation leads to reductions for the environmental impacts affected by NH 3 emission. • Carbon footprint decreases of 12–14%, consumption of fossil & mineral resources increases. [ABSTRACT FROM AUTHOR]

This study addresses the challenge of mitigating ammonia and greenhouse gas (GHG) emissions from stored pig slurry using chemical and biological additives. The research employs dynamic chambers to evaluate the effectiveness of these additives. Chemical agents (sulfuric acid) and biological additives (DAB bacteria) containing specific microbial strains are tested (a mixture of Rhodopseudomonas palustris, Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis, Nitrosomona europea, Nictobacter winogradaskyi, and nutritional substrate). Controlled experiments simulate storage conditions and measure emissions of ammonia, methane, and carbon dioxide. Through statistical analysis of the results, this study evaluates the additives' impact on emission reduction. Sulfuric acid demonstrated a reduction of 92% in CH4, 99% in CO2, and 99% in NH3 emissions. In contrast, the biological additives showed a lesser impact on CH4, with an 8% reduction, but more substantial reductions of 71% for CO2 and 77% for NH3.These results shed light on the feasibility of employing these additives to mitigate environmental impacts in pig slurry management and contribute to sustainable livestock practices by proposing strategies to reduce the ecological consequences of intensive animal farming. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Northeast Colorado's livestock operations have been identified as a major contributor to reactive nitrogen deposition in the Rocky Mountains National Park (RMNP). We present a review on the state of knowledge concerning the emission, transport, deposition, and mitigation of gaseous ammonia (NH3) from open-lot cattle feeding facilities located east of the Northern Front Range of the Rocky Mountains. Gaseous NH3 mitigation strategies discussed are related to diet manipulation and management practices. Crude protein content of 11% and condensed tannins of 8% reduced the NH3 emission by 43% and 57%, respectively. Ambiguous results for NH3 mitigation by using water sprinklers have been reported—an increase in NH3 emission by 27% and decrease of 27 to 56%. Manure harvesting should be evaluated in terms of maintaining proper moisture content, and not necessarily as a mitigation option. The use of chemical and physical manure amendments has shown a wide range in NH3 mitigation effectiveness, ranging from 19 to 98% for chemical and 0 to 43% for physical amendments, respectively. The review outlined the scientific basis, practicality, and expected efficacy of each management practice. The most plausible management practices to reduce NH3 emissions from corral surfaces in cattle feedyards are presented. [ABSTRACT FROM AUTHOR]

With a growing global population and increased environmental concerns around animal agriculture, it is essential to humanely maximize animal performance and reduce environmental emissions. This study aims to determine the efficacy of feeding ractopamine hydrochloride (RAC), an orally active, β 1-adrenergic agonist (β1AA), to feedlot steers in the last 42 d of finishing to reduce ammonia (NH3) emissions and improve animal performance. A randomized complete block design was used to allocate 112 Angus and crossbred Angus steers (initial body weight [BW] = 566.0 ± 10.4 kg) to 8 cattle pen enclosures. Pens (n = 4 per treatment, 14 steers per pen, and 56 steers per treatment) were randomly assigned to one of two treatments: 1) CON; finishing ration containing no RAC, 2) RAC; finishing ration containing 27.3 g/907 kg dry matter (DM) basis RAC. Steers were weighed on day -1 and 0 before treatment and day 14, 28, and 42 during treatment. Treatment rations were mixed and delivered daily by masked personnel. Measured emissions included NH3, nitrous oxide (N2O), methane (CH4), hydrogen sulfide (H2S), and carbon dioxide (CO2). The primary response variables assessed were emissions standardized by live weight (LW) and hot carcass weight (HCW). Steers were harvested on day 43 and carcass data were collected on day 43 and 44. Steers fed RAC reduced NH3 emissions by 17.21% from day 0 to 28 (P = 0.032) and tended to reduce NH3 from day 0 to 42 by 11.07% (P = 0.070) vs. CON. When standardized for LW, NH3 was reduced by 23.88% from day 0 to 14 (P = 0.018), 17.80% from day 0 to 28 (P = 0.006), and 12.50% for day 0 to 42 (P = 0.027) in steers fed RAC vs. CON. Steers fed RAC had 14.05% (P = 0.013) lower cumulative NH3 emissions when standardized by HCW vs. CON. Feeding RAC to Steers reduced H2S by 29.49% from day 0 to 14 (P = 0.009) and tended to reduce H2S over day 0 to 28 by 11.14% (P = 0.086) vs. CON. When H2S emissions were standardized for LW, RAC fed steers had a 28.81% reduction from day 0 to 14 (P = 0.008) vs. CON. From day 0 to 42 the RAC fed steers tended to have a 0.24 kg/d greater average daily gain (ADG) (P = 0.066) and tended to eat 4.27% less (P = 0.069) on a DM basis vs. CON. The RAC fed steers had a 19.95% greater gain to feed ratio (G:F) compared to CON (P = 0.012). Steers fed RAC had an average of 12.52 kg greater HCW (P = 0.006) and an increase of 1.93 percentage units in dressing percent (DP) (P = 0.004) vs. CON. Ractopamine is an effective medicated feed additive for reducing NH3 and improving end product performance through HCW yields.

Low-protein feeding is a strategy used to decrease nitrogen excretion and ammonia (NH3) emissions from animal manure, while maintaining productivity. The optimal protein content depends on many factors, including the type, age, and production level of the animal, as well as the availability, composition, and digestibility of the feed ingredients. Farmers in many developing countries lack information about the protein content of feed and about low-protein feeding, including those in China. This lack of information hinders the making of accurate NH3 emission inventories and strategies for reducing these emissions. We determined farmers' knowledge and perceptions of low-protein feeding in 338 livestock farms, and the actual protein content of 591 feed samples collected from China. Farmers knew little about protein and low-protein feeding; they simply followed the instructions from feed-delivering companies or contracting companies. The mean protein content of the dairy cows' diets (159 ± 20 g/kg DM) was relatively low. Layer hens' diets had a mean protein content of 184 ± 22 g/kg DM, and 14% of their diets were in excess of requirement. Broiler farms used compound feed, of which 23% were in excess of requirement and 15% were deficient in protein. Overall, the mean protein contents were close to the recommended levels for low-protein animal feeding, according to national guidelines, which are similar to the guidelines of the National Research Council (NRC) of the United States. However, there were large variations between farms, suggesting the scope for improvement on many farms. Our research provides farmers, feed companies, policy makers, and institutions with useful information to improve feed management, and to improve the inventories and assessment of NH3 emissions from animal production. [ABSTRACT FROM AUTHOR]

We examine the historical time series data of ammonia emissions from 1770 to 2019 in 37 OECD countries by looking at its statistical properties to determine if the series display time trends and persistence. These two properties are very common in environmental data, and our results indicate that reversion to the mean only occurs in the case of Finland, while the null hypothesis of a unit root cannot be rejected in the case of Norway or Iceland. In all the other cases, the estimated value of the differencing parameter is much higher than 1, and this is consistent for the two assumptions made regarding the error term. Thus, shocks are expected to be permanent in all cases except Finland. Policy implications of the empirical finding are elaborated in the manuscript. [ABSTRACT FROM AUTHOR]

Greenhouse gas (GHG) and ammonia (NH3) emissions, land and water use associated with feedlot cattle (n = 40 hd treatment−1 trial−1) treated with or without productivity-enhancing technologies were modelled for a multiyear study (n = 4). Heifers (H) were assigned to the following treatments: (1) implanted (HTBA); (2) provided with melengestrol acetate (HMGA); (3) nonimplanted control, weight-adjusted (CON_Adj) to achieve the same final carcass weight (CW) as 1 (HCON_AdjTBA); or (4) CON_Adj to achieve the CW as 2 (HCON_AdjMGA). Steers (S) were assigned as follows: (1) implanted (STBA); (2) implanted and provided with ractopamine hydrochloride (SRAC; conducted in the last 2 years); (3) CON_Adj to achieve the same CW as 1 (SCON_AdjTBA); or (4) CON_Adj to achieve the same CW as 2 (SCON_AdjRAC). The GHG and NH3 emissions from HTBA, HMGA, STBA, and SRAC were 3.8%, 3.0%, 10.1%, and 8.5% lower and 4.3%, 2.9%, 7.4%, and 7.6% lower, respectively, than the respective control cattle. The land required to produce feed was also reduced by 6.6%, 4.8%, 9.9%, and 10.9%, while water use was reduced by 6.4%, 4.8%, 10.1%, and 11.1% for HTBA, HMGA, STBA, and SRAC, respectively. This modelling study clearly demonstrates that conventional beef production systems have a lower environmental footprint than nonconventional systems. [ABSTRACT FROM AUTHOR]

The black soldier fly (BSF), Hermetia illucens (Diptera: Stratiomyidae), is an insect commonly used for the bioconversion of various organic wastes. Not only can the BSF convert organic waste into macromolecular organic substances, such as insect proteins, but it can also lessen the pollution associated with these waste products by reducing ammonia emissions, for example. In this study, we measured the effects of adding fruit fermentation broth (Fer) and commercial lactic acid bacteria fermentation broth (Em) to kitchen waste (KW), as deodorizing auxiliary substances, on the growth performance of black soldier fly larvae (BSFL), the intestinal flora structure of BSFL, the ammonia emission from the KW substrate, and the microbial community structure of the KW substrate. We found that the addition of Fer or Em increased the body weight of BSFL after 6 d of culture, increasing the growth rate by 9.96% and 7.96%, respectively. The addition of Fer not only reduced the pH of the KW substrate but also increased the relative abundance of probiotics, such as Lactobacillus, Lysinibacillus, and Vagococcus, which inhibited the growth of ammonifiers such as Bacillus, Oligella, Paenalcaligenes, Paenibacillus, Pseudogracilibacillus, and Pseudomonas, resulting in the reduction of ammonia emission in the KW substrate. Moreover, the addition of Fer or Em significantly increased the relative abundances of Bacteroides, Campylobacter, Dysgonomonas, Enterococcus, and Ignatzschineria in the gut of BSFL and increased the species diversity and richness in the KW substrate. Our findings provide a novel way to improve the conversion rate of organic waste and reduce the environmental pollution caused by BSF. [ABSTRACT FROM AUTHOR]

Aim Ammonia released during the storage period from pig manure causes severe air pollution and odor issues, ultimately leading to nitrogen loss in the manure. In this study, we investigated the application of 13 Bacillus spp. strains isolated from paddy soil and their potential to minimize reactive nitrogen loss during pig manure storage at 28°C and initial moisture content at 76.45%. Methods and results We selected five strains of Bacillus spp. named H3-1, H4-10, H5-5, H5-9, and Y3-28, capable of reducing ammonia emissions by 23.58%, 24.65%, 25.58%, 25.36%, and 26.82% in pig manure over 60 days compared to control. We further tested their ability on various pH, salinity, and ammonium-nitrogen concentrations for future field applications. Our investigation revealed that certain bacteria could survive and grow at pH 6, 8, and 10; 4, 8, and 10% salinity and up to 8 g l−1 of ammonium-nitrogen concentration. Conclusions The results from our study show that saline and ammonium–nitrogen tolerant Bacillus strains isolated from soil can potentially reduce ammonia emissions in pig manure, even at high moisture content during their storage period. [ABSTRACT FROM AUTHOR]

The feasibility of using advanced oxidation processes (AOPs) for abatement of ammonia from livestock buildings was examined in a series of pilot plant experiments. In this study, all the experiments were conducted in a two-step unit containing a dry photolytic reactor (UV185/UV254/O3) and a photochemical scrubber (UV254/H2O2). The unit efficiency was tested for two initial ammonia concentrations (20 and 35 ppmv) and three different air flows (150, 300 and 450 m3·h−1). While the first step removes mainly organic pollutants that are often present together with ammonia in the air and ammonia only partially, the second step removes around 90% of ammonia emissions even at the highest flow rate of 450 m3·h−1. Absorbed ammonia in the aqueous phase can be effectively removed without adjusting the pH (i.e. without the addition of other additives) using UV and ozone. Complete removal of ammonia was achieved after 15 h of irradiation. In order to assess the price efficiency of the suggested technology and to be able to compare it with other methods the figures-of-merit were determined. The price needed for lowering ammonia emission by one order of magnitude is 0.002 € per cubic meter of treated air at the highest flow rate of 450 m3·h−1 and for initial ammonia concentrations of 20 ppmv. These findings demonstrate that AOPs are a promising method for ammonia abatement from livestock buildings which are rarely using any waste air treatment method. [ABSTRACT FROM AUTHOR]

Growing population and consumption pose unprecedented demands on food production. However, ammonia emissions mainly from food systems increase oceanic nitrogen deposition contributing to eutrophication. Here, we developed a long-term oceanic nitrogen deposition dataset (1970 to 2018) with updated ammonia emissions from food systems, evaluated the impact of ammonia emissions on oceanic nitrogen deposition patterns, and discussed the potential impact of nitrogen fertilizer overuse. Based on the chemical transport modeling approach, oceanic ammonia-related nitrogen deposition increased by 89% globally between 1970 and 2018, and now, it exceeds oxidized nitrogen deposition by over 20% in coastal regions including China Sea, India Coastal, and Northeastern Atlantic Shelves. Approximately 38% of agricultural nitrogen fertilizer was excessive, which corresponds to 15% of global oceanic ammonia-related nitrogen deposition. Policymakers and water quality managers need to pay increasingly more attention to ammonia associated with food production if the goal of reducing coastal nitrogen pollution is to be achieved for Sustainable Development Goals. [ABSTRACT FROM AUTHOR]

● It is necessary to address the N flows and their impacts on environment in China for sustainable N management. ● Barriers include better understanding of N cycle mechanisms and improving low cost abatement technologies are needed to overcome. ● Integrated measures and policies are crucial for the abatement of adverse impacts of N. The impacts of nitrogen on environmental quality, greenhouse gas balances, ecosystem and biodiversity in China are of great concern given the magnitude of demand for food and energy. Comprehensive summaries of historic N flows and their critical threats and sustainable management are urgently needed. This paper initially reviews the historical trends of N flows in China and identifies the critical threats of N loss. Subsequently, it describes some recent success stories of N management, and finally indicates barriers to N pollution control. This review highlights three key points. Firstly, a steady increase of N input in China has led to a series of environmental problems via leaching and runoff, ammonia emissions and denitrification. Secondly, although great efforts to improve N management and N safety in China, further quantifications of N flows and analysis of their underlying mechanisms are needed to improve the understanding of the N cycle and pollution control. Finally, it proposes that the best available technologies combined with regulatory plans, laws, projects and policies should be implemented to overcome current barriers in N control and achieve a balance between the sustainable use of N resources and environmental conservation in China.

Objective The objective of this study was to evaluate the effect of waste cooking oil (WCO) addition on ammonia (NH3) emissions during the composting of dairy cattle manure under two aeration conditions. Methods The composting tests were conducted using the laboratory-scale composting apparatuses (14 L of inner volume). Three composting treatments (Control, WCO1.5, and WCO3, with WCO added at 0 wt%, 1.5 wt%, and 3 wt% of manure, respectively) were performed in two composting tests: aeration rate during composting was changed from 0.55 to 0.45 L/min in Test 1, and fixed at 0.3 L/min in Test 2, respectively. The NH3 emitted and nitrogen losses during the composting were analyzed, and the effect of the addition of WCO on NH3 emissions were evaluated. Results Both tests indicated that the composting mixture temperature increased while the weight and water content decreased with increasing WCO content of the composting mixtures. On the other hand, the NH3 emissions and nitrogen loss trends observed during composting in Tests 1 and 2 were different from each other. In Test 1, NH3 emissions and nitrogen losses during composting increased with increasing WCO contents of the composting samples. Conversely, in Test 2, they decreased as the WCO contents of the samples increased. Conclusion The WCO addition showed different effect on NH3 emissions during composting under two aeration conditions: the increase in WCO addition ratio increased the emissions under the higher aeration rate in Test 1, and it decreased the emissions under the lower aeration rate in Test 2. To obtain reduction of NH3 emissions by adding WCO with the addition ratio ≤3 wt% of the manure, aeration should be considered.

This study was to assess the effects of tea residues-fermented feed (TR-fermented feed) on production performance, egg quality, serum antioxidant capacity, caecal microbiota, and ammonia emissions of laying hens. A total of 1,296 Lohmann laying hens have randomly distributed four groups with six parallels and fed with diets TR-fermented feed at the rates of 0 (control), 1, 3, and 5%. The inclusion of 1% (TR)-fermented feed resulted in a significant increase in egg-laying rate and average egg weight of birds, and a reduction in the feed-to-egg ratio when compared to the control group (p < 0.05). The addition of 1 and 3% of (TR)-fermented feed significantly improved the Haugh unit of eggs (p < 0.05). The eggshell thickness was observed to increase by almost one-fold upon the inclusion of 3 and 5% (TR)-fermented feed in the basal diet (p < 0.05). The supplementation of 3% (TR)-fermented feed significantly increased the content of methionine, tyrosine, proline, essential amino acids (EAA), alpha linoleic acid (C18:3n6), docosanoic acid (C22:0), docosahexaenoic acid (C22:6n3), twenty-three carbonic acids (C23:0), ditetradecenoic acid (C24:1) and total omega-3 polyunsaturated fatty acids (∑ω-3 PUFA) in the eggs (p

Postcatalyst ammonia emissions from gasoline vehicles recently received attentions because of their contribution to the formation of urban secondary aerosols. To better understand whether fuel formulation would curb ammonia, the influence of methyl tertiary-butyl ether (MTBE) additive in gasoline on the tailpipe ammonia emissions from six China-6 compliant vehicles was investigated over the World Harmonized Light-duty Test Cycle (WLTC) at −7 °C and 23 °C. Ammonia emissions were measured with MTBE-free and 10 % MTBE-containing China-6 compliant gasoline fuels on the test vehicles. At – 7 °C, the ammonia emissions with and without MTBE addition ranged from 0.15 – 17.07 mg/km and 0.81 − 25.13 mg/km, respectively. At 23 °C, ammonia emissions were 0 − 7.4 mg/km for MTBE-containing fuel and 0 − 8.76 mg/km for MTBE-free fuel. More ammonia emissions were often observed as a result of maneuvering of enriched air-fuel mixtures to improve the combustion stability after cold-start and for de-NOx purpose. Due to the oxygen-containing nature of MTBE, its addition favors ammonia reduction in cold-start tests at – 7 and 23 °C. It is noted that "λ sweep", an engine control strategy injecting extra fuel to deplete stored oxygen in the catalyst and suppress transient NOx formation during reacceleration after prolonged deceleration, may contribute to ammonia emissions due to the use of enriched air-fuel mixtures. [Display omitted] • MTBE addition reduced ammonia in cold-start tests at − 7 and 23 °C. • MTBE addition increased ammonia in warm-start tests at 23 °C. • More ammonia was observed in cold-start and low-temperature tests. • "λ sweep" occurred at deceleration end induced extra ammonia emissions. [ABSTRACT FROM AUTHOR]

The air in the Lombardy Plain, Italy, is one of the most polluted in Europe due to limited atmosphere circulation and high emission levels. There is broad scientific consensus that ammonia (NH 3) emissions have a primary impact on air quality, and in Lombardy, the agricultural sector and livestock activities are widely recognised as being responsible for approximately 97% of regional ammonia emissions due to the high density of livestock. In this paper, we quantify the relationship between ammonia emissions and PM 2.5 concentrations in the Lombardy Plain and evaluate PM 2.5 changes due to the reduction of ammonia emissions through a 'what-if' scenario analysis. The information in the data is exploited using a spatiotemporal statistical model capable of handling spatial and temporal correlation as well as missing data. To do this, we propose a new heteroskedastic extension of the well-established Hidden Dynamic Geostatistical Model. Maximum likelihood parameter estimates are obtained by the expectation–maximisation algorithm and implemented in a new version of the D-STEM software. Considering the years between 2016 and 2020, the scenario analysis is carried out on high-resolution PM 2.5 maps of the Lombardy Plain. As a result, it is shown that a 26% reduction in NH 3 emissions in the wintertime could reduce the PM 2.5 average by 1.44 μ g / m 3 while a 50% reduction could reduce the PM 2.5 average by 2.76 μ g / m 3 which corresponds to a reduction close to 3.6% and 7% respectively. Finally, results are detailed by province and land type. • Analyze ammonia emissions and PM 2.5 levels in Lombardy Plain, Italy. • Propose a heteroskedastic model for spatio-temporal processes like air pollution. • Estimate PM 2.5 reductions from lowered ammonia emissions using scenario analysis. • Create high-resolution maps of PM 2.5 reductions in Lombardy Plain from 2016 to 2020. [ABSTRACT FROM AUTHOR]

Economic sustainability is a primary consideration when contemplating adoption of new farming practices to mitigate climate change. Quantifying the impact of adopting best practices to lower emissions on the profitability of dairy production systems is critical to encouraging rapid adoption at farm level to reach emissions reduction targets. The aim was to evaluate the economic consequences of adoption of best practices to mitigate climate change in a typical compact spring-calving grassland-based system of dairy production in Ireland. Data were collected from compact systems-scale experiments conducted at Solohead Research Farm, Co. Tipperary, Ireland (52°51′N, 08°21′W) between 2011 and 2022. There were three systems that had an average of 27 cows per system per year and an average annual stocking rate of 2.53 cows ha−1. INT was the control in this study and included average annual fertiliser N input of 265 kg ha−1, applied as calcium ammonium nitrate (CAN 27.5 % N) and urea (46 % N) and the average annual clover content of grassland dry matter was 110 g kg−1, and slurry was applied by splash plate. BPN included average annual fertiliser N input of 99 kg ha−1 applied as urea or protected urea, clover content was 230 g kg−1 and slurry was applied by trailing shoe. BPO received minimal (<5 kg ha−1) inputs of fertiliser N, clover content was 280 g kg−1 and slurry was applied by trailing shoe. INT encompassed each of 7 experimental years, BPN 7 years and BPO 4 years. Herbage, milk and other production characteristics were measured. Relevant farm activity data was modelled on the basis of a 50 ha farm to compare the economic performance of the three systems. There were no (P > 0.05) differences in herbage dry matter production per ha and milk production per cow between the three systems. BPO was more (P < 0.05) profitable than INT, whereas BPN was intermediate. Sensitivity of the systems to changing fertiliser N and milk price showed that BPO was more profitable (P < 0.05) in scenarios with intermediate or high fertiliser N prices. BPO had the potential to maintain or improve profitability with substantially lower greenhouse gas and ammonia emissions than conventional grassland-based dairy production (INT). The adoption of practices to lower greenhouse gas emissions from grassland-based dairy production can maintain or improve farm profitability. These results support wider adoption on farms. [Display omitted] • Low emissions grassland-based dairy systems were designed and implemented. • Profitability was evaluated at holistic systems-scale (27 cows per system). • Best practices maintained or improved profitability. • Replacing fertiliser N with biologically fixed N was key to the better outcomes. [ABSTRACT FROM AUTHOR]

The living environment distress is connected currently not only with industrial production but also agriculture is biggest producer of toxic gas – ammonia (NH3) .Emissions of that gas originate mainly in the farm animals breeding and generate within storage and handling with farmyard manure, slurry, poultry excrements and litter. Agriculture influences considerably landscape. has impact on basic effect on soil, water and air. In assessing experiment the preparation Biopolym FZT rumen metabolism and N-balance was found positive effects in terms of increased ammonia nitrogen, the number of ciliates and the reduction of N-compounds in feces. Confirmed the impact on the ammonia content in well-ventilated dairy stable. The economic evaluation depends on the exercise price of milk. In the experiments continued.

The Directive on National Emission Ceilings specifies the reduction of ammonia (NH 3) emissions among other air pollutants, which is most significant for the agricultural sector. The ammonia emission limit set for Hungary was a 10% reduction by 2020, while the target of 32% should be reached by 2030 compared to the 2005 reference year. The paper presents the results of a survey on pig production technology in Hungary from 97 domestic farms. The study aims to know the level of implementation of reduction techniques in livestock production and manure management and highlights the need for further improvements in this production sector. The research found that the application of ammonia reduction techniques was not considered widespread, either in livestock buildings or in manure storage (treatment) and during field application. For almost all (more than 90%) pig production groups, the housing systems were the reference without additional emission reduction. For manure storage, farms have insulated storage under the current regulation, however, significantly more emission reduction technologies were in the variant without cover or crust. Slurry spreading was mainly used with manure application techniques, but more emission-friendly injection and band spreading were also emerging. Besides the expected immediate incorporation, a high proportion of manure was applied between 12 and 24 hours or even after 24 hours. In the studied elements of manure management, significant improvements are needed in applying techniques to reduce ammonia emissions. Effective results can be achieved even by shortening the time between manure application and incorporation with efficient work organization.

Ammonia (NH3) emission from rice fields is a dominant nitrogen (N) loss pathway causing negative impacts on farm profitability and the environment. Reducing N fertilizer application to compensate for N inputs in organic amendments was evaluated for effects on N loss via volatilization, rice yields and post-harvest soil properties in an annual irrigated rice (Boro) – pre-monsoon rice (Aus) – monsoon (Aman) rice sequence. That experiment was conducted using the integrated plant nutrition system (IPNS; nutrient contents in organic amendments were subtracted from the full recommended fertilizer dose i.e., RD of chemical fertilizers) where six treatments with four replications were applied in each season: (T1) no fertilizer (control), (T2) RD, (T3) poultry manure biochar (3 t ha−1; pyrolyzed at 450°C) + decreased dose of recommended fertilizer (DRD), (T4) rice husk ash (3 t ha−1) + DRD, (T5) compost (3 t ha−1) + DRD, and (T6) compost (1.5 t ha−1)+ biochar (1.5 t ha−1) + DRD. The N loss via volatilization varied twofold among seasons being 16% in irrigated rice and 29% in the pre-monsoon rice crop. In irrigated rice, T6 had significantly lower NH3 emissions than all other treatments, except the control while in pre-monsoon and monsoon seasons, T6 and T3 were alike. Pooling the three seasons together, biochar (T3) or biochar plus compost (T6) reduced NH3 loss via volatilization by 36-37% while compost alone (T5) reduced NH3 loss by 23% relative to RD. Biochar (T3) and biochar plus compost mixture (T6) reduced yield-scaled NH3 emissions by 40 and 47% relative to the RD of chemical fertilizer (T2). The organic amendments with IPNS reduced the quantity of N fertilizer application by 65, 7, 24, and 45% in T3, T4, T5, and T6 treatments, respectively, while rice yields and soil chemical properties in all seasons were similar to the RD. This study suggests that incorporation of biochar alone or co-applied with compost and decrease of N fertilizer on an IPNS basis in rice-based cropping systems can reduce N application rates and NH3 emissions without harming yield or soil quality.

It has been demonstrated that biochar has a great potential to reduce volatilisations of ammonia (NH3) from fertilised agricultural soils. While there have been several laboratory studies to demonstrate the effects of biochar on gaseous NH3 emissions, there is hardly any data on the influence of biochar amendments on NH3 volatilisations from the soils under a field environment. Modifying biochar or enriching it with nitrogen (N) may maximise its capacity to abate gaseous NH3 emissions from the soil. Three biochars, i.e. SAB, HPB, and KHB modified through post-pyrolysis treatment with sulphuric acid, hydrogen peroxide, and potassium hydroxide, respectively as well as two biochars enriched with either molten urea (URB) or ammonium nitrate (ANB), were used alongside the pristine biochar (PRB) for comparisons. The quantity of gaseous NH3 evolved from each the biochar amendments including their effects on the growth and yield of the Chinese cabbage plus selected soil chemical properties were evaluated through a field experiment. The control experiment consisted of urea applied alone. In comparison with the control, PRB, KHB, HPB, SAB, URB, and ANB amendments abated NH3 volatilisations from the soil by 44.18%, 45.91%, 63.23%, 65.62%, 72.66%, and 76.71%, respectively. Additionally, PRB, SAB, KHB, HPB, ANB, and URB amendments increased Chinese cabbage yields by 138.5%, 172.0%, 117.3%, 181.1%, 194.0%, and 181.1%, respectively in comparison with the control. The strong linear relationship (r2 = 0.97) between cumulative NH3 emissions and nitrogen use efficiencies indicates that biochar-induced reductions in emissions of gaseous NH3 concomitantly increased the use-efficiencies of the applied N. [ABSTRACT FROM AUTHOR]

Although ammonia emissions are not as huge as carbon and methane emissions, they pose significant threats to ensuring environmental sustainability and productivity. However, the existing literature has paid less attention to the underlying characteristics of ammonia emissions. The chief target of this study is to investigate the stochastic convergence of ammonia emissions at the aggregate level, by sector, and by fuel source in 37 Organization for Economic Cooperation and Development countries for more than two centuries of data. Using a newly proposed Fourier-augmented wavelet unit root test, the empirical findings reveal that the relative ammonia emissions series in most Organization for Economic Cooperation and Development countries follow the unit root process in the aggregate, sectoral, and fuel-specific analyses. Therefore, these findings refer to the existence of divergence, while stochastic convergence does not exist in most cases. Having a divergent pattern of ammonia emissions has several policy implications for policymakers in the context of environmental sustainability. (i) Relative ammonia emission cannot revert to its steady-state path without policy intervention, (ii) policymakers have a chance of affecting the dynamics of ammonia emissions in Organization for Economic Cooperation and Development countries. (iii) As a policy response, the study recommends the pursuant of national environmental policies with consideration to the unique characteristics of the individual countries as the non-existence of convergence of environmental series could result in a diverse level of consciousness of environmental degradation among countries with divergent patterns on emissions levels. [ABSTRACT FROM AUTHOR]

Ammonia emissions are both an environmental and health issue. Biological preparations (also known as biopreparations) have attracted interests as a tool to reduce ammonia emissions from livestock. However, little is known about their effectiveness in modulating evaporating NH3 from manure. The aim of this study was to evaluate the effectiveness of one biopreparation product (MycroZyme© Micron Bio-Systems Ltd., Bridgwater, UK) by studying the dynamics of NH3 gas evolution, taking into account factors such as manure storage time (fresh or stored) and the application method (sprayed or mixed). Experimental studies were performed with control manure (manure without biopreparation) and manure treated with the biopreparation. Data showed that the use of biopreparation slowed down the ammonia emission from manure, so the ammonia concentration in the wind tunnel decreased on average from 21.69 ± 0.9 to 14.43 ± 1.5 ppm. The effect of the biopreparation on ammonia evaporation was higher in the presence of more intensive ammonia emission conditions; i.e., when the manure was fresh, there was no crust on the surface, and the airflow over the manure was intense, and there was a large gradient of ammonia concentration on the manure surface. Based on the obtained results, recommendations were made to reduce ammonia emissions in litter-less cowsheds, where liquid manure is stored. [ABSTRACT FROM AUTHOR]

The living environment distress is connected currently not only with industrial production but also agriculture is biggest producer of toxic gas – ammonia (NH3) .Emissions of that gas originate mainly in the farm animals breeding and generate within storage and handling with farmyard manure, slurry, poultry excrements and litter. Agriculture influences considerably the landscape. It has impact on basic effect on soil, water and air. In assessing experiment the preparation Biopolym Granulat rumen metabolism and N-balance was found positive effects in terms of increased ammonia nitrogen, the number of ciliates and the reduction of N-compounds in feces. It was confirmed the impact on the ammonia content in well-ventilated dairy stable. The economic evaluation depends on the exercise price of milk.

Northeast Colorado’s livestock operations have been identified as a major contributor to reactive nitrogen deposition in the Rocky Mountains National Park (RMNP). We present a review on the state of knowledge concerning the emission, transport, deposition, and mitigation of gaseous ammonia (NH3) from open-lot cattle feeding facilities located east of the Northern Front Range of the Rocky Mountains. Gaseous NH3 mitigation strategies discussed are related to diet manipulation and management practices. Crude protein content of 11% and condensed tannins of 8% reduced the NH3 emission by 43% and 57%, respectively. Ambiguous results for NH3 mitigation by using water sprinklers have been reported—an increase in NH3 emission by 27% and decrease of 27 to 56%. Manure harvesting should be evaluated in terms of maintaining proper moisture content, and not necessarily as a mitigation option. The use of chemical and physical manure amendments has shown a wide range in NH3 mitigation effectiveness, ranging from 19 to 98% for chemical and 0 to 43% for physical amendments, respectively. The review outlined the scientific basis, practicality, and expected efficacy of each management practice. The most plausible management practices to reduce NH3 emissions from corral surfaces in cattle feedyards are presented.

The C/N ratio is an extremely important parameter in the composting process and is directly responsible for the growth of microorganisms. A low C/N ratio contributes to higher emissions of greenhouse gases and odorous substances, such as ammonia (NH3), which is formed by nitrogen mineralization. Due to the highly toxic effects of ammonia, it is a particularly unwanted by-product that can disrupt the composting process since it poisons microorganisms and causes environmental issues. The activity of anammox bacteria, so far analyzed only in wastewater treatment processes, is a particularly efficient method of nitrogen removal, having an advantage over the conventional methods used previously. This study shows the presence of anammox bacteria during composting, which allows for an opportunity to improve the process and reduce its impact on atmospheric pollution. Despite the aerobic nature of this process, the composted mass of waste presents conditions conducive to the development of these ammonia-oxidizing bacteria, as well as the other strains of microorganisms cooperating with them. This makes it possible to compost at a low C/N ratio; in addition, there is no need for an additional energy supply through aeration, as the processes carried out by anammox bacteria do not require oxygen. Therefore, more in-depth research is necessary to evaluate the low C/N effect on anammox and Chloroflexi bacteria growth and its effect on nitrogen balance during composting. [ABSTRACT FROM AUTHOR]

Stand-off pads are uncovered outdoor yards built with absorbent materials, where cattle can be raised to minimize the environmental impact associated with nutrient runoff and gas emissions from manure management. Consequently, they emerge as a prospective alternative to traditional wintering pens, facilitating movement opportunities for dairy cows typically confined to tie-stalls. The objective of this study was to validate the potential of an improved stand-off pad concept (with sphagnum peat moss, woodchips and biochar) aerated with the exhaust air from the adjacent barn, in contrast to a conventional wintering pen, to provide outdoor exercise to dairy cows housed year-round in tie-stall barns Quebec, Canada. Both outdoor yards (28 m2) housed one Holstein dairy cow during 1.5 hr, twice daily (morning and afternoon), throughout two 9-week periods (summer and winter). Sampling of effluents and measurement of greenhouse gases from each area were performed on a weekly basis over the course of the study period for both seasons. Results showed that the stand-off pad was more efficient in removing biochemical oxygen demand, chemical oxygen demand, total nitrogen, suspended solids, and E. coli (32.9, 194.2, 19.8, and 24.3 mg L−1, and 2.2 CFU (100 mL)−1, respectively), relative to the wintering pen (95.3, 379.5, 54.2, and 43 mg L−1, and 197 CFU (100 mL)−1, respectively). Additionally, relative to the wintering pen, the stand-off pad media filter achieved a greater absorption capacity (water effluent volumes of 18.8 m³ and 25.3 m³ respectively). Aeration did not improve the removal of contaminants but resulted in lower nitrous oxide emissions compared to the wintering pen. A nitrogen balance was also calculated, obtaining 62 % recovery for Stand-off pen and 45 % for the winter pen. Improved stand-off pads can indeed provide a more sustainable and comfortable environment for dairy cows. By reducing mud and manure buildup, these pads help maintain cleaner and healthier conditions, which is beneficial for both the cows and the environment. • Stand-off pads offer year-round outdoor access for tie-stall dairy cows. • A mix of sphagnum peat moss, woodchips and biochar is effective in removing contaminants. • Aeration did not improve manure filtration in the stand-off pad during winter. • The stand-off pad was not effective in reducing ammonia emissions. • Nitrogen recovery was greater within the filter media used for the stand-off pad than for the wintering pen. [ABSTRACT FROM AUTHOR]

Lowering greenhouse gas (GHG) and ammonia emissions from ruminant production systems is critical to mitigating climate change and enrichment and acidification of vulnerable habitats. Quantifying emission reductions from the implementation of best practices (BP) on grassland-based dairy systems is essential to guide farmers and policy towards wider adoption of best practices. The aim was to evaluate the extent to which the adoption of BP lowered the GHG and ammonia emissions of grassland-based dairy systems per kg of fat protein corrected milk (FPCM) and per hectare (ha). Life cycle assessment was used to calculate emissions from systems of dairy production adopting BP. Data were collected from systems-scale experiments conducted at Solohead Research Farm, Co. Tipperary, Ireland (52°51′N, 08°21′W) between 2011 and 2022. There were three systems that had an average of 27 cows per system and an average annual stocking rate of 2.53 cows ha−1. INT was the control and included average annual fertiliser N input of 265 kg ha−1, applied as calcium ammonium nitrate (CAN 27.5% N) and urea (46 % N) and average annual clover content of grassland dry matter was 110 g kg−1, and slurry was applied by splash plate. BPN included average annual fertiliser N input of 99 kg ha−1 applied as urea or protected urea, clover content was 230 g kg−1 and slurry was applied by trailing shoe. BPO received minimal (<5 kg ha−1) inputs of fertiliser N, clover content was 280 g kg−1 and slurry was applied by trailing shoe. INT encompassed each of 7 experimental years, BPN 7 years and BPO 4 years. All relevant farm activity data was modelled on the basis of a 59 ha farm. GHG emissions averaged 1.05, 0.80 and 0.73 kg CO 2 e kg FPCM−1 (SEM = 0.035, P < 0.001) for INT, BPN and BPO respectively. GHG emissions per hectare were 15.0, 11.5 and 10.7 t CO 2 e (SEM = 0.485, P < 0.001). Ammonia emissions were lower from BPN and BPO compared with INT (P < 0.001). Replacing artificial fertiliser N with biologically fixed N (BFN) had the largest impact on GHG mitigation. Low emissions slurry spreading (LESS) in the form of the trailing shoe and replacing artificial fertiliser N with BFN had the greatest impact on ammonia emissions. Adopting BP lowered GHG emissions by up to 29 % and ammonia emissions by up to 37 % compared with a conventional intensive system of grassland-based milk production. These results can aid farmers to contribute to emissions reduction targets. [Display omitted] • Various best practices to lower emissions were implemented at system scale (27 cows per system). • Biologically fixed nitrogen in association with clover had a nitrous oxide emission factor of 0 %. • Using minimal fertiliser N and maximising biologically fixed nitrogen was effective at lowering emissions. • Best practices lowered greenhouse gas emissions by up to 29 %. • Best practices lowered ammonia emissions by up to 37 %. [ABSTRACT FROM AUTHOR]

Excessive inorganic fertilization created various environmental problems, and the combination of organic and inorganic fertilization not only maintains crop production but is also environmentally sustainable. A pot experiment was conducted in Yangzhou, China, to investigate the comprehensive effects of organic fertilization combined with inorganic fertilization on the yield and yield components, nitrogen (N) uptake of different organs, and soil-plant system ammonia (NH 3) emissions of two rice cultivars, taking into account the interception of soil NH 3 emissions by the rice canopy. The treatments included the conventional practice of inorganic N applied by local farmers (INO, 270 kg N ha−1), 30 % reduced INO (70 %-INO, 189 kg N ha−1), and organic fertilizer combined with 70 %-INO (ORG-INO). Compared to 70 %-INO, ORG-INO significantly increased grain yield by 38 %, mainly due to more panicles. Similarly, ORG-INO also significantly promoted N uptake in the two rice cultivars, especially in terms of grain N accumulation, relative to 70 %-INO. The increase in grain N accumulation caused by ORG-INO was mainly due to enhanced post-anthesis N uptake, rather than N remobilization of vegetative organs, which also suggested that organic fertilizer could modify the processes of N retention and release. There was no significant difference in rice yield and N accumulation between INO and ORG-INO treatments, which also indicated that ORG-INO was effective in maintaining grain yield while reducing inorganic fertilizer input. Moreover, ORG-INO significantly reduced soil-plant system NH 3 emissions, while the rice canopy intercepted approximately 30 % of soil NH 3 emissions throughout the entire growing season. In summary, ORG-INO treatment significantly reduced the yield-scaled NH 3 emissions, and the partial substitution of organic fertilizers for inorganic fertilizers should be recommended to promote environmental sustainability while ensuring food security. • The organic fertilizer combined with inorganic fertilizers (COM) maintain rice yield. • Fertilizer treatments mainly affect rice yield through panicle number changes. • COM increased the post-anthesis N uptake thereby increasing grain N accumulation. • COM reduced NH 3 the soil-canopy system emissions and yield-scaled NH 3 emission. • The rice canopy intercepts soil NH 3 emissions and should be considered in assessment. [ABSTRACT FROM AUTHOR]

• Natural gas vehicles demonstrated lower NOx emissions than diesel vehicles. • Strong dependence of NOx between drive cycles, with higher NOx under lower loads. • HVO showed NOx reductions for non-SCR vehicles, but not for SCR vehicles. • Natural gas vehicles showed higher ammonia emissions. • N 2 O emissions showed no strong trends, with many vehicles near detection limits. The current study characterized nitrogen oxide (NOx), nitrous oxide (N 2 O), and ammonia (NH 3) emissions from 14 heavy-duty vehicles from different vocations (school bus, transit bus, refuse hauler, delivery vehicle, and goods movement vehicle) over different drive cycles using a chassis dynamometer. Test vehicles with engines ranging in model year from 2009 to 2018 and including diesel and compressed natural gas (CNG) vehicles. The diesel vehicles included both vehicles without selective catalytic reduction (no-SCR) and with SCR certified to the 0.2 g per brake horsepower-hour (g/bhp-hr) [0.27 g/kilowatt-hour (kW-hr)] NOx emissions standard that were operated with diesel fuel, with a subset tested on hydrotreated vegetable oil (HVO). The CNG vehicles were all three-way catalyst (TWC) equipped and certified to either the 0.2 or 0.02 g/bhp-hr NOx standard [0.27 or 0.027 g/kW-hr]. This study is part of a larger project that included over 200 in-use heavy-duty vehicles, which is one of the most extensive studies of emissions from modern heavy-duty vehicles to date. NOx, NH 3 , and N 2 O emissions varied depending on the vocation and the technology. Average NOx emissions for the Urban Dynamometer Driving Schedule (UDDS) cycle over all vehicles ranged from 0.003 to 6.16 g/bhp-hr [0.004 to 8.25 g/kW-hr] and from 0.02 to 17.2 g/mile [0.012 to 10.7 g/km], with the diesel vehicles showing the highest emissions, the 0.2 g/bhp-hr certified CNG vehicles showing lower emissions, and the 0.02 g/bhp-hr certified CNG vehicles showing very low emissions. NOx emissions over other different cycles were generally in the same range as those for the hot start UDDS, with the highway cycles generally showing the lowest emissions. CNG vehicles had relatively high NH 3 emissions ranging from 0.13 to 0.34 g/bhp-hr [0.17 to 0.46 g/kW-hr] and from 0.44 to 0.97 g/mile [0.27 to 0.6 g/km] over the hot start UDDS compared to the SCR-equipped diesel vehicles due to NH 3 formation across the TWC. N 2 O emissions did not show consistent trends and were near/at the detection limits for a number of the vehicles. [ABSTRACT FROM AUTHOR]