Using Spirulina (Limnospira platensis) as an alternative feedstuff for poultry: Effects on ammonia and greenhouse gas emissions from excreta during storage.

Modelling greenhouse gas and ammonia emissions from housing and manure storage in three laying hen production systems

Nitrification inhibitors (NIs) are crucial for enhancing nitrogen use efficiency (NUE), minimizing nitrogen losses, and reducing environmental impacts in agriculture; however, their effectiveness under varying conditions remains unclear. A present meta-analysis assessed how NIs affect crop yields, nitrogen recovery efficiency (REN), soil ammonium (NH 4 + -N), nitrate (NO 3 - -N), ammonia (NH 3 ), and nitrous oxide (N 2 O) emissions, and the results revealed that NIs increase crop yield by an average of 4.7 % with Nitrapyrin, DCD, and DMPP showing specific yields increase of 6.11 %, 4.61 %, and 3.79 %, respectively. Yield increases are most significant with nitrogen rates below 250 kg ha -1 , while rates above this threshold lead to yield declines of 1.76 %. The application of NIs improved REN by 13.14 %, while soil NH 4 + -N levels increased by 42.04 % with the highest increase occurring at lower nitrogen application rates at < 150 kg ha -1 (83.49 %). NIs also reduced soil NO 3 - -N levels by 24.65 % with DCD showing the greatest reduction at -28.17 %, while DMPP had the smallest reduction at -20.04%. the study also revealed cumulative NH 3 volatilization increased by 12.06 %. Among them, DCD and DMPP caused minor increases of 8.52 % and 8.13 %, respectively, while nitrapyrin had little effect, resulting in a 23.42 %. NIs also significantly lowered cumulative N 2 O emissions by 47.39 % relative to the control. Overall, NIs help regulate soil nitrogen levels and mitigate greenhouse gases by slowing nitrification. Their effectiveness may vary based on factors like soil type and management practices, highlighting the need for further research to optimize their use in sustainable nitrogen management strategies. • •Meta-analysis synthesized recent field studies on nitrification inhibitor effects. • •Nitrification inhibitors significantly increased crop yield, nitrogen recovery efficiency (REN), and soil ammonium • •Application reduced N 2 O emissions and nitrate leaching under field conditions. • •NIs help regulate soil nitrogen levels and mitigate greenhouse gases by slowing nitrification

Effects of Straw and Biochar Surface Covers on Ammonia Emission and Nitrogen Speciation during 180-day Pig Manure Storage: a Bench-Scale Screening Study

Ammonia (NH3) slip from transportation and industrial sources contributes to secondary fine particulate matter formation and indirect greenhouse effects, posing growing environmental challenges. The selective catalytic oxidation (SCO) of NH3 to N2 offers an effective abatement route, yet conventional Pt-based catalysts suffer from high noble-metal demand and poor N2 selectivity. Here, we report a bifunctional Pt0.08-Cu/AEI zeolite catalyst synthesized through a mechanochemical ball-milling strategy, which integrates Pt oxidation and Cu reduction functionalities within a single zeolitic framework. Structural analyses reveal that metallic Pt nanoparticles are located on the external surface, while atomically dispersed Cu2+ and CuOx clusters reside within the micropores, enabling intimate Pt-Cu interfacial coupling. Operando DRIFTS-MS results uncover a coupled SCO-SCR mechanism, where NO generated-on Pt sites reacts with adsorbed NH3 on adjacent Cu Lewis acid sites to selectively produce N2, effectively suppressing NOx and N2O formation. Benefiting from this dual-site synergy, the Pt-Cu/AEI-BM1 catalyst with low-Pt content (0.08 wt %) achieves 90% NH3 conversion and >90% N2 selectivity at 200 °C under humid, high-space-velocity conditions. This study demonstrates a scalable and sustainable strategy for designing ultralow-Pt, high-selectivity catalysts for practical ammonia emission control.

A novel process for extracting tungsten from photovoltaic tungsten-based busbars scrap based on molten salt electrolysis.

Existing research has confirmed that nitrogen deposition is a key source of nutrient input in watersheds, but its contribution to riverine carbon, nitrogen loads, and aquatic greenhouse gas (GHG) emissions has not been thoroughly quantified. By developing a multimodel composite framework, this study investigates these contributions in a test watershed and reveals that nitrogen deposition is a disproportionately efficient contributor to aquatic pollutants. While its load (43.11 kg N ha-1 yr-1) is significantly lower than that from agricultural nonpoint sources (248.18 kg N ha-1 yr-1), nitrogen deposition delivers substantially more total nitrogen (TN) and dissolved organic carbon (DOC) per unit of nitrogen input. Consequently, it accounts for considerable portions of riverine loads of nitrate (NO3-, 11.6-17.2%), TN (16.0-19.8%), and DOC (39.2-39.8%), thereby driving 16.34% of aquatic methane (CH4) and 18.56% of nitrous oxide (N2O) emissions. Analysis revealed that reductions in nitrogen deposition have lagged far behind decreases in atmospheric pollutants within the test watershed, highlighting the urgent need to accelerate a cocontrol strategy for atmospheric ammonia, acidic gases, and nitrogen oxide emissions. Moreover, integrating such a strategy with climate change mitigation is crucial for reducing nitrogen deposition. This study provides insights into the relationships among nitrogen deposition, water quality, aquatic GHG emissions, and climate change in agricultural watersheds.

Abstract. Ammonia emissions from agriculture are the primary source of atmospheric reactive nitrogen, significantly impacting air pollution, soil acidification, eutrophication of water bodies, and human health. Accurate quantification of ammonia from different sources is crucial for effective mitigation. In this study, the air extraction method was employed to collect gases from livestock farms, and the δ15N values of volatilized ammonia (NH3) from the animal husbandry industry in the southern Huang – Huai – Hai Plain of China were analyzed using stable nitrogen isotopes. The results show that isotopic signatures differ significantly among livestock types: dairy cows (−20.6 ‰ ± 0.8 ‰), laying hens (−27.4 ‰ ± 1.0 ‰), and pigs (−38.4 ‰ ± 1.7 ‰). These livestock-derived signatures are distinct from those associated with combustion sources (−7.0 ‰ ± 2.1 ‰) and traffic emissions (6.6 ‰ ± 2.1 ‰), and they exhibit considerably lower variability than fertilizer-derived signatures. Overall, this work provides high-precision isotopic source signatures for livestock operations, offering essential parameters for regional atmospheric ammonia source apportionment and highlighting the need for locally tailored mitigation strategies.

Ammonia (NH3) emissions from concentrated animal feeding operations (CAFOs) are recognized contributors to secondary fine particulate matter (PM2.5) formation, yet empirically derived secondary PM2.5 emission factors applicable to livestock operations remain limited. This study investigated NH3-derived secondary PM2.5 formation under controlled laboratory conditions using a PTFE flow reactor in which NH3 was reacted with sulfur dioxide (SO2) across ammonia-rich NH3:SO2 ratios, with and without zero air. The resulting aerosols were characterized using gravimetric analysis, elemental analysis, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDS), and particle size distribution (PSD) measurements. The recovered particles were dominated by inorganic ammonium–sulfur species, with FTIR and elemental trends indicating sulfite-related intermediates under no-zero-air conditions and more oxidized ammonium–sulfur products under oxygenated conditions. Accounting for both filter-collected and wall-deposited particles, unit particulate emission factors normalized to ammonia input were derived. Size-based apportionment using PSD data indicated that approximately 76.6% of the recovered particulate mass was within the PM2.5 size range. Scaling the experimentally derived unit emission factors using literature-based ammonia emission rates yielded an estimated secondary PM2.5 emission factor of 0.351 ± 0.084 g PM2.5 per animal head per day for cattle feedlots, corresponding to approximately 3–4% of reported total PM2.5 emissions. Because the experimental system isolates NH3–SO2 interactions under idealized conditions and does not represent full atmospheric chemistry, the derived values should be interpreted as screening-level estimates of NH3-derived secondary PM2.5 formation potential intended to support comparative air quality assessments of CAFOs rather than direct predictions of ambient PM2.5 concentrations.

Comparative study of real driving ammonia and particle number emissions from plug-in hybrid electric vehicles at sea level and high altitude.

Agricultural soils are major sources of reactive nitrogen (N) gases, yet distinguishing fertilizer-derived emissions from those originating in the soil remains a key challenge for accurate N management. We conducted an in situ 15 N tracing experiment in a maize field in Northeast China using 15 N-labeled urea (49.7 % 15 N, 200 kg N ha⁻¹), integrating passive adsorption and static chamber techniques to quantify source-specific emissions of ammonia (NH 3 ), nitric oxide (NO), and nitrous oxide (N 2 O). The results revealed distinct timing in the peak emissions of these N gases. NH 3 emission peaked first (6.4 kg N ha⁻¹ cumulative loss) and was mainly driven by soil ammonium levels whereas subsequent NO (3.8 kg N ha⁻¹) and N 2 O (1.4 kg N ha⁻¹) peaks were primarily regulated by temperature and soil nitrate availability. The synchronous bimodal 15 N dynamics of NO and N₂O indicated coupled nitrification-denitrification processes, with higher 15 N enrichment in NO (mean 20 %) than in N 2 O (11 %), suggesting stronger nitrification control on NO production. Fertilizer-derived N accounted for 67 %, 52 %, and 30 % of total NH 3 , NO, and N 2 O emissions, respectively. However, fertilizer-induced soil N transformations via priming and legacy effects led to underestimation of the total influence of fertilizer in 15 N tracing. These findings challenge conventional emission factor models, which may overlook indirect N emissions from agricultural inputs, and highlight the need to incorporate soil N priming and legacy dynamics into agricultural N footprint assessments. • In situ quantification of fertilizer-derived NH 3 , NO, and N 2 O emissions using 15 N-urea tracing. • Passive adsorption samplers effectively captured NH 3 and NO emissions from fertilized maize soil. • Fertilizer-derived N contributed 67 %, 52 %, and 30 % of total NH 3 , NO, and N 2 O emissions, respectively. • 15 N enrichment in NO and N 2 O revealed coupled nitrification-denitrification pathways. • Fertilizer-derived gaseous N emissions likely be underestimated due to priming and legacy effects.

Soil mulching enhanced maize canopy ammonia flux in contrast mitigating field ammonia emission

Ammonia (NH3) is a major environmental pollutant, responsible for approximately 50% of the PM2.5 pollution in Europe, contributing to eutrophication and acidification. Approximately 15% and 30% of NH3 is emitted from poultry production systems in Europe and North America, respectively. Therefore, it is important to understand the factors affecting NH3 emission factor (NH3 EF) from poultry production systems. In this study, we analysed the DATAMAN database to identify and quantify NH3 EF for different poultry housing systems. The data was classified into four production systems, including broiler production and layer production in North America and Europe· NH3 EF were calculated for these systems. Results showed that the NH3 EF from Europe-based layer production system was lower (52.7%) than North America-based layer production system; the difference was statistically significant (p=0.0483). Similarly, the NH3 EF for broiler production systems in Europe was 43% lower than that for North American systems (p=0.0084). The effect of litter management systems on NH3 EF was not significant (p=0.387). However, the NH3 EF for European-based new litter system (where the litter is removed after every flock) was 40% lower than North American-based built-up litter system (where several flocks are reared on the same litter). In this study, the EF from studies published after 2010 was 54% lower than those from studies published before 2010 (p=0.007), probably due to improved poultry production systems. Further emission research on newer, improved production systems is required to accurately calculate NH3 EF which is highly needed to improve the emission inventorying of modern poultry houses.

Integrated decontamination of off-odors and ammonia nitrogen in aquaculture using a core-satellite MOF-on-MOF heterostructure.

Abstract. Emissions of ammonia (NH3) from agricultural activities are a major threat to ecosystems and human health. Its quantification via emissions inventories is vital to the understanding of mitigation strategies and policy formation. South Asia, specifically the South Asian Association for Regional Cooperation (SAARC), is a global hotspot of NH3 emissions from agriculture but also an area of great uncertainty due to a lack of data that are representative of local practices. This study presents a single implementation of a framework into which indigenous data can be ingested to adjust such estimates, to provide spatially distributed (0.1° × 0.1°) emissions in five agricultural sectors for improved input data for atmospheric chemistry transport models, by moving away from Tier 1 methods for emission inventories (Tomlinson et al., 2025; https://doi.org/10.5285/e0114a4f-32c2-41d9-9c2a-c46f365d4c30). Results incorporate data such as lower emission factors of NH3 following the application of Urea (13 % of total nitrogen lost as NH3-N) to provide a total estimated emission of NH3 in the SAARC of ∼ 6 Tg (±1.2 Tg), with high values (&gt;5 g NH3 m−2 a−1) in the Indian states Haryana, Punjab and Uttar Pradesh in the Indo-Gangetic Plain (IGP).

Urea volatilization is a major pathway of nitrogen loss and is a source of ammonia emissions in large-scale agriculture. Existing evaluation methods are time-consuming, expensive equipment-dependent, and often rely on empirical correlations without physical meaning. This study introduces a fast and physically grounded approach to quantifying urea volatilization under both laboratory and field conditions. The method integrates simple gravimetric experiments with a mechanistic model that captures the coupled processes of water evaporation, enzymatic hydrolysis, and gas transfer. By estimation of effective parameters directly linked to mass transfer and reaction kinetics, it enables a consistent comparison of fertilizers with distinct mitigation strategies. Results confirm the method’s ability to distinguish barrier, inhibition, and combined effects, showing its reproducibility and physical coherence. This framework provides a practical tool for fast, meaningful evaluation of fertilizer efficiency, contributing to the development of low-emission and sustainable nitrogen management in precision agriculture.

Abstract Agricultural ammonia (NH 3 ) emissions adversely affect air quality, threatening ecosystems and human health. The extent to which global NH 3 emissions respond to a warmer climate and the effects of changing agricultural management practices remain poorly quantified. Here, we show that global warming drives NH 3 emission increases of 5-22% across plausible ranges of climate projections in 2091-2100, with &gt; 10% regional increase in NH 3 emissions per °C warming. A package of six linked measures could reduce present global agricultural NH 3 emissions by 31% but only by 16-28% globally for contrasting climate scenarios (2091-2100), with up to 97% decrease in the effectiveness of measures at a continental scale. Our study underscores the need to consider temperature dependence when evaluating the efficacy of NH 3 emissions reduction policies under a changing climate, and highlights that achieving ambitious NH 3 emission abatement targets will require enhanced efforts to mitigate climate change.

Soil salinization and heavy metal pollution represent significant global challenges to farmland sustainability and food security. Globally, over 800 million hectares of land are affected by salinity, with approximately 17% of cultivated land exhibiting concentrations of at least one heavy metal exceeding established agricultural safety thresholds. Microbially Induced Calcium Carbonate Precipitation (MICP) is an innovative biogeochemical process that harnesses microbial metabolic activities to facilitate soil mineralization. The core mechanism involves ureolytic microorganisms hydrolyzing urea to produce carbonate ions (CO32-). These ions subsequently react with environmental calcium ions (Ca2+) to form insoluble calcium carbonate (CaCO3) precipitates. This review synthesizes recent research progress on the application of MICP technology for the remediation of heavy metal pollution. It elucidates the mechanistic pathways by which MICP immobilizes heavy metal ions and critically evaluates its potential application for ameliorating heavy metal contamination specifically within saline-alkaline soils. Key challenges impeding the broader practical deployment of MICP are analyzed, particularly concerning salt-alkali stress tolerance and the management of ammonia emissions during urea hydrolysis. Emerging strategies, such as the synergistic integration of MICP with biochar amendments, offer promising solutions. Biochar can provide a protective microenvironment for microbial consortia and potentially mitigate ammonia volatilization, thereby enhancing the overall efficacy and feasibility of this remediation approach for contaminated saline-alkaline lands.

The growing greenhouse gas emissions from agricultural production are increasing the pressure on poultry producers to use practices that reduce the environmental impact of farms, mainly by reducing ammonia emissions. The study evaluated the effect of adding effective microorganisms (EMs) and zeolite to litter on productivity, meat quality, selected physiological parameters, and air and litter quality in broiler chickens. In the experimental group, zeolite was applied at 3 kg/10 kg to the litter, and it was sprayed with a solution of EMs and water in a 1:4 ratio. Spraying was repeated weekly until the end of the production cycle. The litter additives reduced the moisture content and pH of the litter (p < 0.05) in the experimental group. This group also showed lower air humidity (p < 0.01) and reduced levels of ammonia and carbon dioxide compared to the control group (p < 0.05). A positive effect of litter additives on production results and the health of broiler chickens was noted. In summary, the addition of 3 kg/10 kg of zeolite to the litter, combined with spraying the litter with a 1:4 solution of EMs and water, can contribute to reducing the emission of harmful gas admixtures generated on broiler farms without negatively affecting production efficiency.

Abstract Food waste digestate (FWD) composting is hindered by severe nitrogen loss, primarily through ammonia (NH 3 ) and nitrous oxide (N 2 O) emissions. While biochar amendment is known to mitigate this loss, the optimal pyrolysis temperature to maximize conservation remains unclear. This study decouples the distinct influence of pyrolysis temperature (300, 400, and 800 °C) of hardwood biochar on nitrogen conservation by linking biochar properties to microbial community dynamics. A critical trade-off is revealed: 300 °C biochar maximized NH 3 reduction (39.2% vs. control, n = 2, p &lt; 0.05) but was coincided with the enrichment of nirK/S -harboring denitrifiers (e.g., Luteimonas ), posing a potential challenge from increased N 2 O emissions. Conversely, 800 °C biochar achieved the greatest N 2 O reduction (47.5% vs. control, n = 2, p &lt; 0.05), an outcome consistent with suppressed microbial denitrification. Critically, biochar produced at 400 °C achieved an optimal balance, likely through enhanced NH 3 adsorption and the fostering of a microbial community correlated with lower N 2 O emissions, which ultimately led to a 46.3% reduction in total nitrogen loss (vs. control, n = 2, p &lt; 0.05), the highest performance among all treatments. This work guides the selection of biochar pyrolysis temperature toward targeted nitrogen conservation and sustainable FWD valorization. Graphical Abstract