Search

Different technologies can be utilised to mitigate environmentally harmful ammonia (NH 3) emissions after field application of liquid animal manure (slurry). After a solid-liquid separation, air-plasma technology can acidify the liquid fraction and enrich its nutrient value by increasing the amount of inorganic nitrogen. The present work investigates the emissions of NH 3 and volatile organic compounds (VOC) after field application of the following fractions of pig slurry and slurry digestate: i) untreated slurry (UN), ii) liquid fraction of slurry (LF), iii) liquid fraction of slurry treated with air from the plasma treatment (LP). Emissions were measured with a system of wind tunnels and a cavity ring-down spectrometer for NH 3 concentration measurements and a proton-transfer-reaction mass-spectrometer for measurements of VOC. For both slurry types, the cumulative NH 3 emissions were in the following order UN > LF > LP. All the differences were significant (P < 0.05), except between pig slurry LF and LP. The reduction in cumulative NH 3 emission obtained by the treatments compared to UN were 55–74% and 70–89% for LF and LP, respectively. The slurry separation decreased dry matter by 46–54% and resulted in a rapid decrease in slurry exposed surface area after application, presumably due to high infiltration. Several VOCs were measured after application of the slurry, but continuous emission was undetectable for all VOCs. The very low VOC emission was presumably due to high infiltration of the low dry matter slurry treatments and low concentration of VOC in the digestate. Science4Impact Statement • Separation with decanter centrifuge reduced slurry DM by 46–54%. • Treatment with plasma treated air lowered slurry pH by 1.6–1.8 units. • Separation of slurry decreased cumulative NH 3 emissions by 55–74%. • Separation + treatment with plasma treated air reduced NH 3 emission by 70–89%. • All slurry types investigated had low VOC fluxes after application. [ABSTRACT FROM AUTHOR]

China's sustained air quality improvement is hindered by unregulated ammonia (NH3) emissions from inefficient nitrogen management in smallholder farming. Although the Chinese government is promoting a policy shift to large-scale farming, the benefits of this, when integrated with nitrogen management, remain unclear. Here we fill this gap using an integrated assessment, by combining geostatistical analysis, high-resolution emission inventories, farm surveys and air quality modeling. Smallholder-dominated farming allows only 13%–31% NH3 reduction, leading to limited PM2.5 decreases nationally due to non-linear PM2.5 chemistry. Conversely, large-scale farming would double nitrogen management adoption rates, increasing NH3 reduction potential to 48%–58% and decreasing PM2.5 by 9.4–14.0 μg·m−3 in polluted regions. The estimated PM2.5 reduction is conservative due to localized NH3-rich conditions under large-scale livestock farming. This strategy could prevent over 300 000 premature deaths and achieve a net benefit of US $68.4–86.8 billion annually, unlocking immense benefits for air quality and agricultural sustainability. [ABSTRACT FROM AUTHOR]

Reducing environmental pollution, including air pollution, contributes to improving people's health and quality of life, which is one of the goals of sustainable development. One of the important air pollutants is ammonia, which is mainly emitted from the agriculture sector. This sector is responsible for over 81% of global ammonia emissions. The aim of this research was a preliminary assessment of the implementation status of methods for reducing ammonia emissions on farms and to learn the views and awareness of agricultural producers on reducing emissions of pollutants into the air. The research was conducted using a survey questionnaire that was made available to farmers in various ways. Based on the results, it can be concluded that farmers have knowledge of environmental protection and agree that people have an impact on the environment. Low-emission practices to reduce ammonia emissions from agricultural sources are not widely used. The best situation is considering reduction practices in the storage of natural fertilizers and the use of low-emission fertilizer application techniques. The results of this type of monitoring research may be useful in determining the level of ammonia emission reduction. In the future, the data may be used during air pollution inventories conducted by state institutions. [ABSTRACT FROM AUTHOR]

Background: Anthropogenic ammonia emissions, primarily derived from agriculture, lead to air pollution, soil acidification, and surface water eutrophication, all of which adversely affect human health and ecosystems. Slurry treatment technologies in the form of additives represent an underutilized means of reducing gaseous emissions. Information regarding the potential of additives to reduce ammonia in soil surface‐applied slurries is scarce. Aim: This study aims to develop a 15N mass balance technique to quantitatively measure ammonia losses from different slurries containing multiple additives that are applied to outdoor soil‐filled containers. Methods: The experiments were performed under free‐air conditions. Isotopically labeled slurries from biogas, cattle, and pigs containing 18 additives were surface‐applied to soil‐filled containers and exposed for 72 or 48 h. The additives included inorganic and organic adsorbents, five amounts of sulfuric acids, molasses ± effective microorganisms, and water dilution. After termination of the ammonia loss period, a suite of soil preparation steps for the quantitative recovery of the labeled ammonium remaining in the soil was developed, and subsequently the loss of NH4‐N was determined. Results: In the control treatments, ammonia losses from biogas, cattle slurries, and pig slurries averaged 54.4%, 33.9%, and 11.0%, respectively. The adsorbents did not decrease or only slightly decreased ammonia emissions. Ammonia abatement by sulfuric acid was nearly complete at pH values of 5.9 and 5.8 for the biogas and pig slurry, respectively, and about 80% at pH 5.2 for the cattle slurry. In comparison, more moderately decreased pH values with sulfuric acid showed a similar reduction as molasses and a 1:1 dilution for the three slurries. Adding microorganisms to the molasses did not further decrease ammonia losses. Conclusion: The newly developed 15N mass balance technique, which allows a precise estimate of ammonia losses, can serve as a reference method to assess ammonia losses from field‐applied slurries containing various additives and as a standard comparison technique for other ammonia measurement techniques. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Dairy slurry could be a significant source of nitrogen (N) for plants, but mismanagement can lead to atmospheric ammonia losses or nitrate leaching into groundwater. To make the use of dairy slurry efficient and reasonable, the loss of N pollution to the environment should be reduced. We used repacked lysimeters to comprehensively determine ammonia emission and N leaching losses in an alfalfa–soil system. The application of dairy slurry had no significant effect on alfalfa yield at the same rate of N application in comparison to chemical fertilizer, and adding humic acids significantly increased yield by about 12%. However, the application of dairy slurry increased the ammonia emission rate significantly, leading to an increase in the cumulative amount of ammonia emission, while the addition of humic acids reduced the ammonia emissions by 11%. Chemical fertilizer and dairy slurry application significantly increased nitrate leaching compared to the control treatment, while the addition of humic acids can significantly reduce ammonium N leaching. Dairy slurry was proven to be as effective as chemical N fertilizer in achieving the optimum biomass, and adding humic acids can significantly reduce N loss to the atmosphere and groundwater. This study showed the possibility of replacing chemical fertilizer with dairy slurry in alfalfa production and the advantages of humic acids' addition to alfalfa to maintain production yield and improve environmental friendliness. [ABSTRACT FROM AUTHOR]

The extensive utilization of nitrogen (N) fertilizers within maize cultivation systems has resulted in diminished nitrogen use efficiency (NUE) and contributed to nitrogen pollution on a global scale. To assess the ecological repercussions of excessive fertilization, it is imperative to elucidate both the nitrogen use efficiency and the fate of nitrogenous fertilizers upon application. The current research evaluated the potential of a newly developed slow-release nitrogen fertilizer on maize growth and its behavior in soil under controlled conditions. Six different levels of urea fertilizer (UF) and slow-release nitrogen fertilizer (SRNF) were administered within the field, representing 100%, 85%, and 70% of the recommended application rates. The slow-release nitrogen fertilizer (SRNF) exhibited superior performance regarding growth, yield and nutrient retention in comparison to urea fertilizer (UF). Moreover, minimal ammonia emissions were detected with the employment of the slow-release nitrogen fertilizer (SRNF), while other urea-based fertilizers proved inefficient in mitigating ammonia emissions, despite enhancing various growth and yield parameters. The efficiency in nutrient recovery followed a distinct pattern, with polymer-coated fertilizers demonstrating superiority. The plots treated with SRNF displayed significantly higher growth and yield characteristics compared to those treated with urea fertilizer. In terms of NH3 volatilization, the urea fertilizer (UF) treatment at 100% application rate showed higher emissions (1.99 mg g-1) after a 27-day incubation period, as opposed to the slow-release nitrogen fertilizer (SRNF) treatment (1.68 mg g-1). Leaching data indicated that urea fertilizer treatments led to greater losses of NO3-N (2.01 mg L-1) compared to SRNF treatments (0.88 mg L-1). [ABSTRACT FROM AUTHOR]

ABSTRACT: Poultry farming generates significant poultry litter (broiler litter and laying hen manure), posing environmental and human health risks. Heat treatment, particularly through drying, can mitigate these adverse effects. This paper aimed to explore the impact of various drying methods of poultry litter on key process indicators. The literature review showed that the drying kinetics of the broiler litter in a hot air dryer is affected by the manure depth, air velocity, drying temperature, and air relative humidity. Nevertheless, the effect of the air relative humidity is insignificant on drying laying hen manure. Hot air drying, freeze drying, and oven drying have significant effects on the nutrient content of the broiler litter. In drying both broiler litter and laying hen manure, the specific energy consumption decreases as air temperature and relative humidity rise. Low temperatures cause poor bacteria destruction in poultry litter, but at temperatures over 50°C, Salmonella is completely destroyed. The ammonia release from laying hen manure and broiler litter is very sensitive to moisture content. Generally, air temperature, air velocity, manure depth, and air relative humidity positively correlate with ammonia emission. The average ammonia emission during belt drying of laying hen manure is about 209.3 mg NH3 d-1 hen-1. Finally, the lack of comprehensive research on poultry litter drying with modern drying methods (ultrasound, microwave, infrared rays, and freeze drying) is evident. One approach that may offer new opportunities is hybrid methods, such as a combination of dryers that use hot air drying agents with these modern drying methods.

Acidification of slurry is a promising approach for reducing ammonia emissions during the application procedure. Since only a few studies have been conducted focusing on ammonia emissions during the application of liquid organic fertilizers on the soil surface, a suitable incubation system was developed to evaluate the effects of acidification under controlled conditions. This incubation system was used to measure the ammonia emissions of various liquid organic fertilizers. The substrates were acidified with sulfuric and citric acid to different pH values to determine both the influence of the pH value of the substrates and of the type of acid on the ammonia emissions. The emissions decreased with declining pH value, and the reduction in emissions compared to the initial pH of the substrate was over 86% for pH 6.5 and over 98% for pH 6.0 and below. At the same pH value, the ammonia emissions did not differ between substrates acidified with citric acid and sulfuric acid, although more than twice as much 50% citric acid was required compared to 96% sulfuric acid to achieve the same pH value. Overall, our results demonstrate that the incubation system used is suitable for measuring ammonia emissions from surface-applied liquid organic fertilizers. The system allows for the differentiation of emission levels at various pH levels and is therefore suitable for testing the effectiveness of additives for reducing ammonia emissions from liquid organic fertilizers. [ABSTRACT FROM AUTHOR]

Granulation is an important class of production processes in food, chemical and pharmaceutical manufacturing industries. In urea fertilizer manufacturing, fluidized beds are often used for the granulation system. However, the granulation processes release ammonia to the environment. Ammonia gas can contribute to eutrophication, which is an oversupply of nitrogen and acidification to the ecosystems. Eutrophication may cause major disruptions of aquatic ecosystems. It is estimated that global ammonia emissions from urea fertilizer processes are approximately at 10 to 12 Tg N/year, which represents 23% of overall ammonia released globally. Therefore, accurate modeling of the ammonia emission by the urea fertilizer fluidized bed granulation system is important. It allows for the system to be operated efficiently and within sustainable condition. This research attempts to optimize the model of the system using the particle swarm optimization (PSO) algorithm. The model takes pressure (Mpa), binder feed rate (rpm) and inlet temperature (°C) as the manipulated variables. The PSO searches for the model's optimal coefficients. The accuracy of the model is measured using mean square error (MSE) between the model's simulated value and the actual data of ammonia released which is collected from an experiment. The proposed method reduces the MSE to 0.09727, indicating that the model can accurately simulate the actual system. [ABSTRACT FROM AUTHOR]

Ammonia emissions from livestock farms are a major problem for staff and residents near these centers. Anaerobic decomposition of livestock waste and the collection and stacking of waste are the main sources of ammonia gas on livestock farms. This article examined ammonia emissions from livestock facilities near Tehran Imam Khomeini International Airport. First, field measurements were made in the summer (30°C), and collected samples were examined using the indophenol technique. AERMOD, based on Gaussian fluctuating plume theory, was constructed to model ammonia emissions. According to AERMOD, the maximum periodic‐seasonal 2‐hourly and 8‐hourly ammonia concentrations were 15.9, 229, and 63.7 OU (odor unit per unit volume)/m3, respectively. The hourly ammonia emission rate from livestock sources is also 0.0168 gm−2 h−1. AERMOD results mathematical model indicated reasonable agreement with the field measurement, which the coefficient of determination (R2), index of agreement (d), and efficiency coefficient (E) were 0.95, 0.97, and 0.91, respectively. Moreover, Statistical indices, including geometric mean bias (MG), geometric variance (VG), fraction of predictions within a factor of two of observations (FAC2), and normalized mean square error (NMSE), the root mean square error (RMSE) and mean absolute error (MAE) are also indicated by 1.36 and 0.67, respectively, were used to assess the reliability of the model results showed that AERMOD had a good agreement with the field measurement. [ABSTRACT FROM AUTHOR]

Simple Summary: Predicting emissions from livestock housing is crucial for helping farmers understand how various factors impact emissions at the pig house level. This knowledge empowers decision-makers and the farmers to make informed choices that encourage emission reduction and improve air quality in pig houses. To create innovative, low-emission pig housing systems, the development of a prediction model appears to be a straightforward solution. This paper introduces such a model for predicting methane and ammonia emissions from two commercial pig houses with two manure management systems: one with long storage in deep pits and the other with short storage, through daily flushing of a shallow pit with sloped walls (a reduced emitting surface) and partial manure dilution. This simulation model, which considers factors like animal weight, age, feed, and pen dimensions as input data, calculates manure quantity and quality, as well as methane and ammonia emissions over the growing period. In this model, the calculation of ammonia emission involves aggregating emissions from various sources identifiable within pig houses. These sources include manure channels, slatted floors, and solid floors, encompassing fouled areas, pigs, and pen partitions. This model successfully predicts the development of methane and ammonia emissions based on animal and farm characteristics. This paper describes a model for the prediction of methane and ammonia emissions from fattening pig houses. This model was validated with continuous and discrete measurements using a reference method from two manure management systems (MMS): long storage (LS) in deep pits and short storage (SS) by daily flushing of a shallow pit with sloped walls and partial manure dilution. The average calculated methane and ammonia emissions corresponded well with the measured values. Based on the calculated and measured results, the average calculated CH4 emission (18.5 and 4.3 kg yr−1 per pig place) was in between the means from the continuous data from sensors (15.9 and 5.6 kg yr−1 per pig place) and the means from the discrete measurements using the reference method (22.0 and 3.1 kg yr−1 per pig place) for the LS and SS systems, respectively. The average calculated NH3 emission (2.6 and 1.4 kg yr−1 per pig place) corresponded well with the continuous data (2.6 and 1.2 kg yr−1 per pig place) and the discrete measurements using the reference method (2.7 and 1.0 kg yr−1 per pig place) from LS and SS, respectively. This model was able to predict the reduction potential for methane and ammonia emissions by the application of mitigation options. Furthermore, this model can be utilized as a predictive tool, enabling timely actions to be taken based on the emission prediction. The upgraded model with robust calculation rules, extensive validations, and a simplified interface can be a useful tool to assess the current situation and the impact of mitigation measures at the farm level. [ABSTRACT FROM AUTHOR]

The extensive utilization of nitrogen (N) fertilizers within maize cultivation systems has resulted in diminished nitrogen use efficiency (NUE) and contributed to nitrogen pollution on a global scale. To assess the ecological repercussions of excessive fertilization, it is imperative to elucidate both the nitrogen use efficiency and the fate of nitrogenous fertilizers upon application. The current research evaluated the potential of a newly developed slow-release nitrogen fertilizer on maize growth and its behavior in soil under controlled conditions. Six different levels of urea fertilizer (UF) and slow-release nitrogen fertilizer (SRNF) were administered within the field, representing 100%, 85%, and 70% of the recommended application rates. The slow-release nitrogen fertilizer (SRNF) exhibited superior performance regarding growth, yield and nutrient retention in comparison to urea fertilizer (UF). Moreover, minimal ammonia emissions were detected with the employment of the slow-release nitrogen fertilizer (SRNF), while other urea-based fertilizers proved inefficient in mitigating ammonia emissions, despite enhancing various growth and yield parameters. The efficiency in nutrient recovery followed a distinct pattern, with polymer-coated fertilizers demonstrating superiority. The plots treated with SRNF displayed significantly higher growth and yield characteristics compared to those treated with urea fertilizer. In terms of NH3 volatilization, the urea fertilizer (UF) treatment at 100% application rate showed higher emissions (1.99 mg g-1) after a 27-day incubation period, as opposed to the slow-release nitrogen fertilizer (SRNF) treatment (1.68 mg g-1). Leaching data indicated that urea fertilizer treatments led to greater losses of NO3-N (2.01 mg L-1) compared to SRNF treatments (0.88 mg L-1).

Abstract Management of nitrogen (N) fertilizer is a critical factor that can improve maize (Zea mays L.) production. On the other hand, high volatilization losses of N also pollute the air. A field experiment was established using a silt clay soil to examine the effect of sulfur-coated urea and sulfur from gypsum on ammonia (NH3) emission, N use efficiency (NUE), and the productivity of maize crop under alkaline calcareous soil. The experimental design was a randomized complete block (RCBD) with seven treatments in three replicates: control with no N, urea150 alone (150 kg N ha−1), urea200 alone (200 kg N ha−1), urea150 + S (60 kg ha−1 S from gypsum), urea200 + S, SCU150 (sulfur-coated urea) and SCU200. The results showed that the urea150 + S and urea200 + S significantly reduced the total NH3 by (58 and 42%) as compared with the sole application urea200. The NH3 emission reduced further in the treatment with SCU150 and SCU200 by 74 and 65%, respectively, compared to the treatment with urea200. The maize plant biomass, grain yield, and total N uptake enhanced by 5–14%, 4–17%, and 7–13, respectively, in the treatments with urea150 + s and urea200 + S, relative to the treatment with urea200 alone. Biomass, grain yield, and total N uptake further increased significantly by 22–30%, 25–28%, and 26–31%, respectively, in the treatments with SCU150 and SCU200, relative to the treatment with urea200 alone. The applications of SCU150 enhanced the nitrogen use efficiency (NUE) by (72%) and SCU200 by (62%) respectively, compared with the sole application of urea200 alone. In conclusion, applying S-coated urea at a lower rate of 150 kg N ha−1 compared with a higher rate of 200 kg N ha−1 may be an effective way to reduce N fertilizer application rate and mitigate NH3 emission, improve NUE, and increase maize yield. More investigations are suggested under different soil textures and climatic conditions to declare S-coated urea at 150 kg N ha−1 as the best application rate for maize to enhance maize growth and yield.

Management of nitrogen (N) fertilizer is a critical factor that can improve maize (Zea mays L.) production. On the other hand, high volatilization losses of N also pollute the air. A field experiment was established using a silt clay soil to examine the effect of sulfur-coated urea and sulfur from gypsum on ammonia (NH3) emission, N use efficiency (NUE), and the productivity of maize crop under alkaline calcareous soil. The experimental design was a randomized complete block (RCBD) with seven treatments in three replicates: control with no N, urea150 alone (150 kg N ha−1), urea200 alone (200 kg N ha−1), urea150 + S (60 kg ha−1 S from gypsum), urea200 + S, SCU150 (sulfur-coated urea) and SCU200. The results showed that the urea150 + S and urea200 + S significantly reduced the total NH3 by (58 and 42%) as compared with the sole application urea200. The NH3 emission reduced further in the treatment with SCU150 and SCU200 by 74 and 65%, respectively, compared to the treatment with urea200. The maize plant biomass, grain yield, and total N uptake enhanced by 5–14%, 4–17%, and 7–13, respectively, in the treatments with urea150 + s and urea200 + S, relative to the treatment with urea200 alone. Biomass, grain yield, and total N uptake further increased significantly by 22–30%, 25–28%, and 26–31%, respectively, in the treatments with SCU150 and SCU200, relative to the treatment with urea200 alone. The applications of SCU150 enhanced the nitrogen use efficiency (NUE) by (72%) and SCU200 by (62%) respectively, compared with the sole application of urea200 alone. In conclusion, applying S-coated urea at a lower rate of 150 kg N ha−1 compared with a higher rate of 200 kg N ha−1 may be an effective way to reduce N fertilizer application rate and mitigate NH3 emission, improve NUE, and increase maize yield. More investigations are suggested under different soil textures and climatic conditions to declare S-coated urea at 150 kg N ha−1 as the best application rate for maize to enhance maize growth and yield. [ABSTRACT FROM AUTHOR]

Environmentalists are now becoming very concerned about issues related to air pollutants especially ammonia emissions from the broiler industry. Ammonia produced by broiler farms not only has a detrimental effect on the health and productivity of broiler chickens, but also has a severe influence on the environment. The ammonia emissions from broiler chicken houses can be effectively reduced by lowering the protein content of the feed, although broiler growth performance can suffer as a result. To improve protein digestibility and utilization in broiler chickens, enzymes can be used as feed additives. Hence, enzymes can avoid feeding with excessive protein content to broilers. Due to its ability to improve digestion and retention of N in the body, enzymes especially protease can reduce N excretion through excreta so that it has an impact on reducing ammonia emissions from broiler chicken houses. This present review provides an overview of the role of enzymes in reducing ammonia emissions from broiler farms. The mechanism of how enzymes reduce ammonia emissions from broiler farms is also discussed in this review. [ABSTRACT FROM AUTHOR]

ABSTRACT: The type of litter material has direct impacts on production, behavioral, and welfare parameters of broilers. The price of conventionally-used litter materials is increasing. Salvinia molesta is a fast-growing aquatic plant which has become an environmental issue in some areas. This study assessed the suitability of air-dried Salvinia plants (SAL) as an alternate litter material to paddy husk (PH). Resulting in a completely randomized experiment, a total of 240 broilers was raised in 12 floor-pens each provided with either PH or SAL as litter materials, from 11 to 36 d. Scan sampling technique was employed to record the birds’ engagement in 15 predetermined behaviors. Foot pad dermatitis (FPD), hock burn damage (HBD) and plumage cleanliness (PC) were assessed using Welfare Quality Scoring System. Litter samples were analyzed for pH, dry matter%, water holding capacity, porosity, N%, tapped-density and ammonia emission rate. The litter material had no significant effect (P > 0.05) on mortality, growth performance parameters, dressing % and visceral organ weight. The scores for FPD and PC were unaffected by the litter materials. SAL litter reported significantly lower (P < 0.05) HBD scores. The percentages of birds engaged in eating and wing flapping behaviors were significantly lower on SAL. Litter type had no significant influence on the color, aroma, flavor, texture and overall acceptability of breast meat. Air-dried Salvinia plants reported acidic pH. SAL litter gave a significantly higher tapped-density. Ammonia emission rate of SAL litter was significantly lower than that of PH. However, the final litter N content was higher for PH (3.7%) than SAL (3.2%). The study proposes air-dried Salvinia plants as a litter material for broilers since it gives growth performance comparable to PH with reduced hock burn damage incidences. Effects of SAL on behavior and the fertilizer value of the spent litter are to be studied further.

Objectives This study aimed to monitor ammonia volatilization in upland fields under different nitrogen fertilizer applications, comparing compost manure (CM) and composite fertilizer (CF) and investigate the environmental factors influencing ammonia volatilization. Methods Ammonia was collected using the static chamber method in upland fields, and the soil analyses were conducted before and after ammonia volatilization monitoring. Pearson's correlation analysis and machine learning were utilized to determine the relationship between ammonia volatilization and environmental factors. Growth characteristics of harvested crops were analyzed, and Duncan analysis confirmed significant differences between nitrogen fertilizer treatments. Results and Discussion In both CM and CF fertilized fields, there was no significant difference in ammonia volatilization. However, more ammonia volatilization was observed in the potato field compared to the Chinese cabbage field, attributed to higher NH4+-N content in the soil of the potato field. Machine learning identified soil temperature and moisture as significant factors affecting ammonia volatilization. The analysis of crop growth revealed a positive effect of increased nitrogen fertilizer application. The result showed that single CM application was insufficient to meet crop nutrient demands. Conclusion This study quantified ammonia emissions, identified influencing factors, and provided valuable data for enhancing fertilizer use efficiency and nitrogen management strategies in agriculture.

ABSTRACT: This study aimed to evaluate trade-offs between enteric and manure CH4 emissions, and the size of synergistic effects for CH4 and nitrogenous emissions (NH3 and N2O). Sixty-four Holstein-Friesian cows were blocked in groups of 4 based on parity, lactation stage, and milk yield. Cows within a block were randomly allocated to a dietary sequence in a crossover design with a grass silage-based diet (GS) and a corn silage-based diet (CS). The GS diet consisted of 50% grass silage and 50% concentrate, and CS consisted of 10% grass silage, 40% corn silage, and 50% concentrate (dry matter basis). The composition of the concentrate was identical for both diets. Cows were housed in groups of 16 animals, in 4 mechanically ventilated barn units for independent emission measurement. Treatment periods were composed of a 2-wk adaptation period followed by a 5-wk measurement period, 1 wk of which was without cows to allow separation of enteric and manure emissions. In each barn unit, ventilation rates and concentrations of CH4, CO2, NH3, and N2O in incoming and outgoing air were measured. Cow excretion of organic matter was higher for CS compared with GS. Enteric CH4 and cow-associated NH3 and N2O emissions (i.e., manure emissions excluded) were lower for CS compared with GS (−11, −40, and −45%, respectively). The CH4 and N2O emissions from stored manure (i.e., in absence of cows) were not affected by diet, whereas that of NH3 emission tended to be lower for CS compared with GS. In conclusion, there was no trade-off between enteric and manure CH4 emissions, and there were synergistic effects for CH4 and nitrogenous emissions when grass silage was exchanged for corn silage, without balancing the diets for crude protein content, in this short-term study.

Dairy slurry could be a significant source of nitrogen (N) for plants, but mismanagement can lead to atmospheric ammonia losses or nitrate leaching into groundwater. To make the use of dairy slurry efficient and reasonable, the loss of N pollution to the environment should be reduced. We used repacked lysimeters to comprehensively determine ammonia emission and N leaching losses in an alfalfa–soil system. The application of dairy slurry had no significant effect on alfalfa yield at the same rate of N application in comparison to chemical fertilizer, and adding humic acids significantly increased yield by about 12%. However, the application of dairy slurry increased the ammonia emission rate significantly, leading to an increase in the cumulative amount of ammonia emission, while the addition of humic acids reduced the ammonia emissions by 11%. Chemical fertilizer and dairy slurry application significantly increased nitrate leaching compared to the control treatment, while the addition of humic acids can significantly reduce ammonium N leaching. Dairy slurry was proven to be as effective as chemical N fertilizer in achieving the optimum biomass, and adding humic acids can significantly reduce N loss to the atmosphere and groundwater. This study showed the possibility of replacing chemical fertilizer with dairy slurry in alfalfa production and the advantages of humic acids’ addition to alfalfa to maintain production yield and improve environmental friendliness.

Ammonia (NH3) emissions should be mitigated to improve environmental quality. Croplands are one of the largest NH3 sources, they must be managed properly to reduce their emissions while achieving the target yields. Herein, we report the NH3 emissions, crop yield and changes in soil fertility in a long-term trial with various fertilization regimes, to explore whether NH3 emissions can be significantly reduced using the 4R nutrient stewardship (4Rs), and its interaction with the organic amendments (i.e., manure and straw) in a wheat–maize rotation. Implementing the 4Rs significantly reduced NH3 emissions to 6 kg N ha–1 yr–1 and the emission factor to 1.72%, without compromising grain yield (12.37 Mg ha–1 yr–1) and soil fertility (soil organic carbon of 7.58 g kg–1) compared to the conventional chemical N management. When using the 4R plus manure, NH3 emissions (7 kg N ha–1 yr–1) and the emission factor (1.74%) were as low as 4Rs, and grain yield and soil organic carbon increased to 14.79 Mg ha–1 yr–1 and 10.09 g kg–1, respectively. Partial manure substitution not only significantly reduced NH3 emissions but also increased crop yields and improved soil fertility, compared to conventional chemical N management. Straw return exerted a minor effect on NH3 emissions. These results highlight that 4R plus manure, which couples nitrogen and carbon management can help achieve both high yields and low environmental costs.

This study aimed to evaluate trade-offs between enteric and manure CH 4 emissions, and the size of synergistic effects for CH 4 and nitrogenous emissions (NH 3 and N 2 O). Sixty-four Holstein-Friesian cows were blocked in groups of 4 based on parity, lactation stage, and milk yield. Cows within a block were randomly allocated to a dietary sequence in a crossover design with a grass silage-based diet (GS) and a corn silage-based diet (CS). The GS diet consisted of 50% grass silage and 50% concentrate, and CS consisted of 10% grass silage, 40% corn silage, and 50% concentrate (dry matter basis). The composition of the concentrate was identical for both diets. Cows were housed in groups of 16 animals, in 4 mechanically ventilated barn units for independent emission measurement. Treatment periods were composed of a 2-wk adaptation period followed by a 5-wk measurement period, 1 wk of which was without cows to allow separation of enteric and manure emissions. In each barn unit, ventilation rates and concentrations of CH 4 , CO 2 , NH 3 , and N 2 O in incoming and outgoing air were measured. Cow excretion of organic matter was higher for CS compared with GS. Enteric CH 4 and cow-associated NH 3 and N 2 O emissions (i.e., manure emissions excluded) were lower for CS compared with GS (−11, −40, and −45%, respectively). The CH 4 and N 2 O emissions from stored manure (i.e., in absence of cows) were not affected by diet, whereas that of NH 3 emission tended to be lower for CS compared with GS. In conclusion, there was no trade-off between enteric and manure CH 4 emissions, and there were synergistic effects for CH 4 and nitrogenous emissions when grass silage was exchanged for corn silage, without balancing the diets for crude protein content, in this short-term study. [ABSTRACT FROM AUTHOR]

Reducing ammonia (NH 3 ) emissions and nitrogen (N) losses in the process of dung and urine storage are crucial for waste resources utilization and air pollutants reduction in stockbreeding industry. We selected the fresh mixture of cow dung and urine from the intensive livestock farm in Qinghai-Tibetan Plateau as the research object. Urease inhibitor (N-(n-butyl) thiophosphoric triamide, NBPT), nitrification inhibitor (3.4-dimethylpyrazole phosphate, DMPP) and alum were added to the fresh cattle feces, and the nutrient contents and NH 3 fluxes under different inhibitor treatments during 22 days of feces storage were tested. The structural equation model was employed to analyze the effects of various factors on NH 3 emissions and N transformations during the storage of feces. The results showed that (1) Nitrification inhibitor and low-dose alum addition had no effects on N losses and ammonia emissions during the storage of feces. But the cumulative emissions of NH 3 in NBPT treatment was reduced by 25.07% than the control group. (2) During the short-term storage of feces and urine, total organic nitrogen content in NBPT treatment increased by 43.86 % compared with the control group, while the ammonium nitrogen content decreased by 39.15%, and the average C:N ratio increased by 20.99 %. (3) The higher water content was beneficial to reducing the NH 3 emissions during the storage of feces. Meanwhile, urease inhibitor could reduce ammonium nitrogen production and NH 3 flush by reducing total organic nitrogen decomposition and C:N rate. Shortly, urease inhibitor could effectively slow down N losses and NH 3 release by controlling the ammonium production in short-term storage in the processing of cow dung and urine mixture, while the optimal application conditions of nitrification inhibitor and alum need to be further studied. [ABSTRACT FROM AUTHOR]

One of the most important environmental worries related to poultry production is ammonia gas emission which is affected by poultry manure moisture. This research was aimed at investigating poultry manure drying in a hot air dryer and its influence on ammonium nitrogen losses to provide an overview of ammonia gas emissions and absorption of emitted ammonia by a spray scrubber. The effect of air temperature (60–80 °C), air relative humidity (8–18 %), manure depth (2–4 cm), and air velocity (2–3 m s−1) were analyzed to optimize the drying process. The optimization of ammonia absorption involved analyzing the effects of absorbent solution temperature (30–50 °C), solution pH (2−4), and nozzle operating pressure (0.2–0.6 Mpa). The Box–Behnken design was applied to optimize these processes. Manure depth was the factor that had the most significant effect on both drying duration and ammonia emission (ammonium nitrogen losses). during the drying process, the ammonium nitrogen losses increased with increasing the manure depth and decreasing the air velocity and air temperature. The optimum ammonium nitrogen was 570,330 mg h lit−1 at an air temperature of 60 °C, air relative humidity of 8.11 %, manure depth of 3.95 cm, and air velocity of 2 m s−1. Both the temperature of the absorbent solution and the solution pH had opposite effects on the ammonia absorption. Increasing nozzle operating pressure increased ammonia absorption. The maximum ammonia absorption was obtained at a solution temperature of 49.2 °C, solution pH of 2, and nozzle operating pressure of 0.58 Mpa. At these conditions, the amount of ammonium sulfate in the absorbent solution was 9.09 g lit−1 and the efficiency of the spray scrubber was 66.79 %. So, we can be sure that ammonia emission from poultry manure and the absorption of emitted ammonia can be controlled by varying the investigated variables. [ABSTRACT FROM AUTHOR]

Simple Summary: Ammonia, as one pf the capital greenhouse gases, induces a negative influence on the growth performance, immune responses, and oxidative capacity of broilers. The present study indicated that Lactobacillus plantarum administration decreased ammonia emission, the contents of serum urea nitrogen and ammonia, fecal urease, and ammonium nitrogen. L. plantarum supplementation increased the concentration of major serum immunoglobulins and intestinal short-chain fatty acids, as well as the serum total-antioxidant capacity and glutathione peroxidase. Moreover, birds fed with Lactobacillus plantarum supplementation showed modulated cecal microflora and a changed the serum metabolome, including glyoxylate and dicarboxylate, pyruvate and thiamine metabolism, melanogenesis, and citrate cycle. From the present study, it can be seen that L. plantarum supplementation could be one potential method for decreasing NH3 emission in poultry production. Probiotic supplementation has become a prominent method of decreasing ammonia emissions in poultry production. The present study was conducted to investigate the influence of Lactobacillus plantarum on ammonia emission, immune responses, antioxidant capacity, cecal microflora and short chain fatty acids, and serum metabolites in broilers challenged with ammonia. A total of 360 1-day-old yellow-feathered broilers were randomly divided into three treatment groups: birds fed with a basal diet (CON), a basal diet supplemented with ammonia (AN), and a basal diet supplemented with 2.5 × 108 CFU L. plantarum kg−1 and challenged with ammonia (LP). Data showed that L. plantarum supplementation decreased ammonia more than 30% from day 48, and significantly reduced the levels of serum urea nitrogen and ammonia, fecal urease, and ammonium nitrogen compared with those on CON. Compared with AN and CON treatments, LP administration increased (p < 0.05) the concentration of serum immunoglobulin Y (IgY), IgM, and IL-10, as well as the serum total-antioxidant capacity (T-AOC) and GSH-Px, and decreased (p < 0.05) IL-1β, IL-6, and TNF-α. Furthermore, birds supplemented with LP had higher (p < 0.05) cecal contents of short chain fatty acids (SCFAs) than AN birds and had more butyrate than CON birds. Data from 16s high throughput sequencing showed that LP supplementation significantly increased (p < 0.05) the Shannon and Simpson indices of bird cecal microflora, and Alloprevotella dominated the LP birds. The function prediction of cecal microflora indicated that LP treatment significantly increased alanine aspartate and glutamate metabolism, starch and sucrose metabolism, exosome, mismatch repair, homologous recombination, DNA repair and recombination proteins, and amino acid-related enzymes. The serum metabolome showed that LP supplementation significantly changed the aminoacyl-tRNA, pantothenate and acetyl-coenzyme A, arginine, phenylalanine, tyrosine and tryptophan, valine, leucine, and isoleucine biosynthesis; purine, beta-alanine, galactose, histidine, alanine, aspartate and glutamate, glyoxylate and dicarboxylate, pyruvate and thiamine metabolism, melanogenesis, and citrate cycle. [ABSTRACT FROM AUTHOR]

The Chinese government aims at reducing nutrients losses from agriculture through incentivising the substitution of synthetic fertilizer by animal manure applications. This paper addresses the question how different substitution ratios affect crop yield, nitrogen (N) utilization efficiency (NUE), ammonia (NH3) volatilization and the N balance of a typical winter wheat–summer maize double cropping system. A field experiment was conducted with six treatments, including a no N treatment and five N substitution ratios (100%, 75%, 50%, 25% and 0%), between October 2016 and September 2018. The yield and NUE were highest with a partial N substitution (75% inorganic N fertilizer + 25 manure N). Mean yields were 8553 kg ha−1 for wheat and 10,620 kg ha−1 for maize in the treatment with 75% inorganic N + 25% manure N. Mean NUE was 55% for wheat and 45% for maize in this treatment. The mean N balance, N uptake, and soil residual Nmin increased, while NH3 emissions and N surpluses decreased with an increasing substitution of synthetic N fertilizer by manure N. A substitution of 25% of the inorganic N fertilizer by manure N showed the best performance. Selecting the appropriate ratio of synthetic N fertilizer to manure is an effective pathway for green agricultural development, as it ensures a high crop yield and N utilization, and reduces the environmental cost of food production. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Acidification of slurry is a promising approach for reducing ammonia emissions during the application procedure. Since only a few studies have been conducted focusing on ammonia emissions during the application of liquid organic fertilizers on the soil surface, a suitable incubation system was developed to evaluate the effects of acidification under controlled conditions. This incubation system was used to measure the ammonia emissions of various liquid organic fertilizers. The substrates were acidified with sulfuric and citric acid to different pH values to determine both the influence of the pH value of the substrates and of the type of acid on the ammonia emissions. The emissions decreased with declining pH value, and the reduction in emissions compared to the initial pH of the substrate was over 86% for pH 6.5 and over 98% for pH 6.0 and below. At the same pH value, the ammonia emissions did not differ between substrates acidified with citric acid and sulfuric acid, although more than twice as much 50% citric acid was required compared to 96% sulfuric acid to achieve the same pH value. Overall, our results demonstrate that the incubation system used is suitable for measuring ammonia emissions from surface-applied liquid organic fertilizers. The system allows for the differentiation of emission levels at various pH levels and is therefore suitable for testing the effectiveness of additives for reducing ammonia emissions from liquid organic fertilizers.

This paper describes a model for the prediction of methane and ammonia emissions from fattening pig houses. This model was validated with continuous and discrete measurements using a reference method from two manure management systems (MMS): long storage (LS) in deep pits and short storage (SS) by daily flushing of a shallow pit with sloped walls and partial manure dilution. The average calculated methane and ammonia emissions corresponded well with the measured values. Based on the calculated and measured results, the average calculated CH4 emission (18.5 and 4.3 kg yr−1 per pig place) was in between the means from the continuous data from sensors (15.9 and 5.6 kg yr−1 per pig place) and the means from the discrete measurements using the reference method (22.0 and 3.1 kg yr−1 per pig place) for the LS and SS systems, respectively. The average calculated NH3 emission (2.6 and 1.4 kg yr−1 per pig place) corresponded well with the continuous data (2.6 and 1.2 kg yr−1 per pig place) and the discrete measurements using the reference method (2.7 and 1.0 kg yr−1 per pig place) from LS and SS, respectively. This model was able to predict the reduction potential for methane and ammonia emissions by the application of mitigation options. Furthermore, this model can be utilized as a predictive tool, enabling timely actions to be taken based on the emission prediction. The upgraded model with robust calculation rules, extensive validations, and a simplified interface can be a useful tool to assess the current situation and the impact of mitigation measures at the farm level.

Simple Summary: Ammonia (NH3) and hydrogen sulfide (H2S) are obnoxious gases with characteristic odors. They are environmental contaminants and could be harmful to animals and humans. Measurement of NH3 and H2S from dairy farms is still limited, especially for Chinese dairy farms. In this study, we measured ammonia and hydrogen sulfide from 11 barns from 3 dairy farms in central China during winter. Next, we calculated the average daily emission rates for these two gases. Finally, we extrapolated our results to estimate the NH3 emission from the Chinese dairy production. There is an urgent need for accurate measurement for emissions of ammonia (NH3) and hydrogen sulfide (H2S) in dairy barns in order to obtain reliable emission inventories and to develop and evaluate abatement strategies. This experiment was performed on three dairy farms in central China during 14 consecutive days in the winter 2020. Concentrations of NH3 and H2S were measured every two hours. The samples were taken inside and outside of barns from 7 sites at two heights (at floor and 1.5 over the floor). The results show that the average NH3 concentration was 2.47 mg/m3 with a maximum of 4.62 mg/m3, while the average H2S concentration was 0.179 mg/m3 with a maximum of 0.246 mg/m3. Lactating cows produced significantly more NH3 (3.73 mg/m3 versus 2.34 mg/m3) and H2S (0.24 mg/m3 versus 0.14 mg/m3) than non-lactating cows. NH3 and H2S concentrations were higher at 0 m than at 1.5 m, especially during the day. In addition, the average daily emission rates per animal unit (AU = 500 kg weight) were 23.5 g and 0.21 g for NH3 and H2S, respectively. The emission rate for NH3 was then used to extrapolate the NH3 emission from the Chinese dairy production. Our estimation for 2016 was 0.45 Tg, and it could reach 1.35 Tg by 2050. These numbers reflected our first attempt to calculate emission inventories for the Chinese dairy industry. Our results also suggest that more concrete measures must be taken to reduce the uncertainties of NH3 emissions from dairy cow production in China. [ABSTRACT FROM AUTHOR]

The study was established to examine the effect of three biochar types (orange peels biochar (OPB), sorghum panicles biochar (SPB), and wood chips biochar (WCB)) prepared at low temperature (270 °C) added at four doses (0, 1, 3, and 6% w/w) on ammonia (NH3) volatilization and chemical characteristics of a saline soil treated with urea. The results revealed that treating the saline soil with different biochar types at all doses caused a significant reduction of cumulative NH3 volatilization compared to the unamended soil. The effectiveness of biochar types in decreasing NH3 volatilization from this soil was: WCB > SPB > OPB > unamended soil. Soil pH decreased significantly with applying different types and doses of biochar. Treating the saline soil with 3% each of SPB and WCB and 6% WCB decreased electrical conductivity significantly in the soil extract compared to the unamended soil. The sodium adsorption ratio decreased significantly with applying SPB and WCB at 3 and 6%. The biochar produced at a low temperature was found to have an acidic effect. Accordingly, biochar applications are currently one of the most promising technologies and practices for rehabilitation and sustainable management of saline soils as well as mitigating climate change. [ABSTRACT FROM AUTHOR]

This research aimed to assess the impact of probiotic supplementation in the broiler diet on growth performance, nutrient utilization, noxious gas emissions, excreta micromiota and meat quality. One thousand six hundred and twenty male Ross 380 broilers (one‐day‐old, body weight, 42 ± 0.5 g and 5‐week trial) were arbitrarily chosen and assigned to three nutritive treatments (basal diet and basal diet included with 0.1%, and 0.2% probiotic mixture [Bacillus subtilis 7.0 × 107 cfu/g, Bacillus licheniformis 4.1 × 107 cfu/g]) with 30 duplicates (18 birds each). Probiotic inclusion linearly increased (p < 0.05) broiler body weight gain (BWG) during Phases 1, 2 and the overall period and decreased (p < 0.05) feed conversion ratio (FCR) linearly on Phase 2 and the overall period. However, feed intake (FI) and mortality rate remained unaffected (p > 0.05). Though nutrient digestibility of nitrogen (N) tendency to increase (p < 0.05), dry matter (DM) and energy (E) did not influence (p > 0.05). Inclusion of a probiotic supplement linearly increased (p < 0.05) Lactobacillus and reduced Salmonella (p < 0.05) counts in broilers. Moreover, broilers fed a diet supplement with probiotic addition linearly decreased (p < 0.05) NH3, H2S, C2O and acetic acid emissions. The graded level of probiotic addition linearly reduced (p < 0.05) cooking loss and the tendency to decrease (p < 0.05) weight of bursa of Fabricius, but had no effect (p > 0.05) on other meat quality measures. These findings indicated that increasing the level of probiotics in feed could improve growth efficiency, nutrient absorption, microbial index, meat quality and reduce gas emissions in broilers. [ABSTRACT FROM AUTHOR]

Saltpetre (KNO3) manufacture was a principal monopoly industry in early Modern India when the United Kingdom governed the social and economic systems. The process represented microbial transformation of excrementitious livestock and human wastes deposited around habitats, resulting in formation of salt efflorescence at an economic scale. Low caste people collected these wastes for extraction and production of rough saltpetre under the administrative control of British India. Stable isotope composition (δ15N and δ18O) was used to trace details of the microbial transformation processes, often involving the isotopic fractionation of nitrogen and oxygen. Marked elevation in δ15N and δ18O values for nitrates in soils and deposits, relative to those of primary organic nitrogen in diets and water sources, characterizes the unique processes of historic saltpetre manufacture in British India. [ABSTRACT FROM AUTHOR]

A rapid growth in monolithic residential construction over recent decades has created a problem associated with ammonia contamination inside newly constructed buildings. Absence of substantiated preventive actions aimed at minimizing ammonia emissions hinders commissioning of new residential buildings and may create an unfavorable sanitary-epidemiological situation with obvious olfactory-reflex and irritating effects on public health. The aim of this study was to develop a scientifically grounded method to predict when ammonia concentrations emitted from concrete constructions would reach their permissible levels in air inside contaminated premises in newly constructed buildings. Ammonia emissions were estimated based on data of laboratory tests that involved analyzing indoor air samples taken in Saint Petersburg and the Leningrad region. Indoor air was analyzed in 4 newly constructed residential buildings (165 premises, 57 test protocols, 893 air samples tested to identify ammonia in them). Relationships between changes in ammonia concentrations and ventilation time were obtained by using regression analysis (regression equation, least square method). To establish reproducibility of the results and a possibility to compare them, we tested variances for homogeneity by using Fisher criterion. Sampled populations were compared with Student’s t-test in case the data fitted to a normal distribution (Kolmogorov – Smirnov test, Shapiro – Wilks test). Critical significance was taken at 0.05 in all the statistical comparisons. We have developed a method for predicting when ammonia concentrations that occurred in indoor air inside newly constructed buildings due to multi-day emissions from building materials would reach their permissible levels. The method involves multi-day measurements (y, mg/m3) of ammonia concentrations sequentially in each premise inside a newly constructed building on any day of measurements during the time period t; building up relationships between averaged ammonia concentrations (yav, mg/m3) and a time moment t; mathematical analysis of the obtained relationships by parameterization and statistical analysis of the obtained kinetic parameters.

This study identified the need to develop ammonia (NH3) emission factors for biogas production facilities in Korea and examined the base unit that should be considered when developing emission factors. The analysis showed that the ammonia concentration of three biogas production facilities ranged from approximately 0.04 to 8 ppm. The NH3 emission factors were found to be 0.005 kg NH3 ton-waste and 0.150 kg NH3/10−3 Nm3-biogas. The estimated emission factors were also used to calculate the total emissions, which were found to be small. The uncertainty of the emission factors ranged from approximately −5% to +8% for the waste-based emission factors and approximately −5% to +7% for the biogas-based emission factors. Although the uncertainty of the emission factor differences is not large, it is low compared to the international emission factor uncertainty (maximum 191%, minimum −40.7%). Considering the development of waste-based and biogas-based emission factors, there is not much difference in terms of uncertainty of emission factors, so it is judged that it will be easier to develop emission factors based on biogas production in terms of securing and managing overall data. [ABSTRACT FROM AUTHOR]

In this trial, the effects of different nutritional treatments on the N balance parameters of fattening pigs in the 55–65 kg live weight category were evaluated. The following diets were used: control diet (C) and low-protein (LP) diet with 2% crude protein reduction, with and without 10% sugar beet pulp (S) or 0.5% benzoic acid supplementation. Six pigs per treatment with similar live weight were used, and in the context of the balance trial, the daily N intake, fecal and urinary N excretion and the pH of urine were measured. From the data N digestibility, the TAN % and N retention were calculated. Feeding LP diets reduced the fecal, urinary and total N excretion and also the pH of urine significantly compared with the control diet. Sugar beet pulp significantly increased the fecal N excretion and urinary pH, and it also reduced significantly N digestibility and the TAN ratio. Benzoic acid failed to reduce urinary pH. The measured N excretion, retention and TAN excretion values were more favorable than those that can be found in the different guidelines or those used in the Hungarian ammonia emission inventory. [ABSTRACT FROM AUTHOR]

In the present study, a numerical model was developed to predict the flow pattern inside a broiler building. The model was intended to predict the velocity fields inside the domain and the ammonia (NH3) emitted or released by litter from poultry housing. The numerical model was developed in computational fluid dynamics (CFDs) commercial code and intended to represent a commercial broiler building and to simulate the 3D and heat transfer in steady-state flow. The evaporative cooling pads were also included in the model. The validation of the model was based on experimental measurements obtained in previous studies. The simulations were focused on the summer, winter, and mid-season conditions. Numerical measurements of NH3 concentration were compared with the experimental measurements, and a quite good agreement was verified. The numerical results allowed the characterization of: the inside flow pattern developed for the summer and winter periods and the NH3 and velocity field distributions inside the broiler building. It was found that NH3 concentration increased along the tunnel, as a result, especially, of the low flow rate of the exhaust fan. It was verified that the low velocities inside domain were not sufficient to remove the gaseous pollutants. [ABSTRACT FROM AUTHOR]

Ammonia (NH3) emissions from intensive anthropogenic activities is an important component in the global nitrogen cycle that has triggered large negative impacts on air quality and ecosystems worldwide. An accurate spatially explicit high resolution NH3 emission inventory is essential for modeling atmospheric aerosol pollution and nitrogen deposition. However, existing NH3 emission inventories in China are still subject to several uncertainties. In this review we firstly summarize the widely used methods for the estimate of NH3 emissions and discuss their advantages and major limitations. Secondly, we present aggregated data from ten NH3 emission inventories to assess the trends in total anthropogenic NH3 emissions in China over the period 1980–2019. Almost emission estimates reported that NH3 emissions in China have doubled in the last four decades. We find a substantial differences in annual total NH3 emissions, spatial distributions and seasonal variations among selected datasets. In 2012, the median emission (Tg yr−1) and associated minimum-maximum ranges are 12.4 (8.5_17.2) for total emission, 9.9 (8.1_13.8) for agriculture, 0.3 (0.2_1.0) for industry, 0.4 (0.2_1.1) for residential and 0.1 (0.1_0.3) for transport and other emission of 1.5 (0.3_2.6). In general, peak emissions occur in summer but in different months, the higher NH3 emission intensities are concentrated in the NCP area, and in eastern and south-central China but distinct regional discrepancy among selected datasets. Finally, we made an analysis of the reasons and levels of difference in NH3 emission estimates with recommendations for improvement of China’s NH3 emission inventory.

Simple Summary: Ammonia emission is a main air quality issue worldwide and related mostly to animal production. This ratio in the European Union is about 80–90%. Ammonia is released from the manure, mainly from the nitrogen excreted via urine. There are several nutritional tools to decrease the N-excretion of the animals. Among them feeding low protein diets supplemented with crystalline ammino acids is probably the most efficient. However, feed additives, like exogenous enzymes, pro- and prebiotics can also modify the amount of the excreted N as well as its composition. There are lots of information on how the probiotics and prebiotics can modify the microbiota composition in the different gut segments. On the other hand, few results exist on how this modified microbiota can affect the ratio of the faecal and urinary nitrogen or the ureolytic activity of the excreted microflora. Therefore, in the present work the effects of different cereal grains with different soluble fibre fractions and a probiotic and symbiotic treatment was evaluated. The objective of this research was to determine whether diet composition, or adding probiotic or symbiotic feed additives to broiler diets can modify the N composition of the excreta and the dynamics of ammonia volatilization from the manure. A total of 574 one-day-old Ross 308 broiler chickens were fed four different diets. The treatments included a corn and soybean meal-based control diets (C), wheat-based and wheat bran containing diets (W), a multi-strain probiotic treatment (Broilact®; Br), and a symbiotic additive containing Bacillus subtilis, inulin, and Saccharomices cerevisiae (Sy). Feeding the wheat-based diet significantly improved the weight gain and FCR of chickens. Treatment W also significantly increased the dry matter content of the excreta compared with the probiotic and symbiotic treatments. Both Br and Sy tended to decrease the amount of excreted uric acid, which is the main substrate of ammonia. Treatment Sy reduced the urinary N ratio of the excreta in comparison with treatment W. The symbiotic additive resulted in significantly higher ammonia emission in the first two hours. On the other hand, the dynamics of the emission was slow at the beginning and increased steeply after 15 h when the wheat-based diets were fed. Based on our results, the wheat-based diets, containing soluble arabinoxylans, and the symbiotic treatments of broiler diets have an impact on the urinary and faecal nitrogen composition of the excreta, and also on the dynamics of ammonia release from the manure. [ABSTRACT FROM AUTHOR]

Plant nutrition is an essential element for crop production and enormous amounts of fertilizers are used in agricultural systems. However, these sources emit toxic gasses and compounds in the environment that not only deteriorate soil quality but also cause a reduction in the use efficiency of applied nutrients. Therefore, the value addition of these fertilizer sources by coating micronutrients, microbes, polymers or other organic and inorganic compounds have been advocated recently. The present study aimed to evaluate the effectiveness of value-added fertilizer sources for growth and yield improvement of Zea mays (Pioneer-30T60) and Oryza sativa (Super Basmati-515) with a reduction in ammonia volatilization and an improvement in nutrient recovery by crop grains. Different phosphorus (P), potassium (K) and nitrogen (N) fertilizer sources (Di-ammonium phosphate (DAP), polymer coated DAP, zarkhez plus NPK, urea, polymer-coated urea and zabardast urea) were used in different combinations keeping one control for N. The results revealed that maximum growth, yield and nutrient recovery was shown by polymer-coated urea and DAP followed by zarkhez plus NPK and zabardast urea. Moreover, a minimum ammonia emission was recorded by polymer-coated fertilizers, but other value-added fertilizers were found inefficient in reducing ammonia emission, though these sources improved all growth and yield attributes. Nutrient recovery efficiency was patterned as; polymer coated fertilizers > zarkhez plus NPK + zabardast urea > zarkhez plus NPK + urea > DAP + zabardast urea > DAP + urea > DAP. Thus, the use of polymer-coated fertilizers was beneficial for both the reduction in ammonia volatilization and for improving nutrient use efficiency with maximum crop benefits. [ABSTRACT FROM AUTHOR]

The aim of the study was to evaluate the lactational unit production of urea and ammonia emissions from cows kept in eastern Poland. The study covered 1089 lactations of Polish Holstein-Friesian cows born between 1992 and 2018 in 15 cattle herds located in the Masovian and Podlaskie Voivodeships. The amount of urea excreted in the urine and nitrogen compounds in the faeces was calculated based on the following regression equations: (y = 15.46 × urea concentration in milk (g/L) + 193.4); y = 11.42 × urea concentration in milk (g/L) + 41.93); y = 4.05 × urea concentration in milk (g/L) + 151.47). Several factors affecting the total production of urea were examined: four groups of animals were distinguished according to their milk yield in 305-day lactation; three groups based on year of birth; four age groups; and three groups according to urea content in milk. The results of the study showed that the average concentration of urea in cow urine was 78.6 kg, and the ammonia emission from a lactating cow was 44.6 kg. The study demonstrated large variation in the amount of nitrogen compounds excreted in faeces and the degree of ammonia emission risk among animals. The main factors differentiating the amount of nitrogen compounds in the urine and faeces and the level of ammonia emission into the atmosphere included the cow's production level, its year of birth, and urea content in milk. These results can be used to assess the potential risk of ammonia emissions from dairy cattle farming to the environment. The data obtained in the study, in addition to their pure scientific value, can serve as a source of information for national centres responsible for monitoring and assessing the threat of ammonia emissions to the environment. [ABSTRACT FROM AUTHOR]

Urea is a renowned nitrogen (N) fertilizer widely used in plant N nutrition owing to its high N concentration (46%). The effect of the N application rate on ammonia (NH3) emission into the environment and soil properties is yet to be unraveled. The rate of NH3 emission from sandy loam soil amended with manure compost (T1: 5000 kg ha−1) and urea at different application rates (100, 200, and 400 kg N ha−1 designated as T2, T3, and T4, respectively) with 3 replications was evaluated in an incubation experiment. Ammonia emission was rapid at the early stage of the experiment followed by an equilibrium decrease that tends toward zero at the end of the incubation. Ammonia emissions of 16.50, 52.15, and 75% of applied N in T2, T3, and T4 were observed on day 49. Ammonia emission increased linearly (y = 0.7823x−32.169, R2 = 0.95**) in response to N application rates. T1 conserves more NH4+ (20.79 mg kg−1) in the soil, followed by T2 (11.8 mg kg−1) and T3 (11.7 mg kg−1). T2 and T3 reduced the soil pH to optimal for microbial activities and nutrient availability, while T4 promoted soil acidity. A balanced combination of compost and urea mitigates NH3 volatilization and improves soil fertility. In conclusion, applying compost (5000 kg ha−1) with urea at 100 kg N ha−1 or 200 kg N ha−1 is recommended for NH3 volatilization mitigation, nitrification inhibition, and efficient NH4+ retention in the soil. [ABSTRACT FROM AUTHOR]

Ammonia is emitted from compost piles with inherent spatial heterogeneity, while adjusting carbon to nitrogen (C/N) ratios can mitigate ammonia emissions. However, the role of spatial heterogeneity in composting bacterial communities mediating nitrogen conversion remains unclear. This study explored bacterial spatial heterogeneity at different locations in piles and its links to ammonia emission during chicken manure composting under increased C/N ratios. Compared with manure-only composting (C/N ratio 7), composting under increased C/N ratios of 16 reduced ammonia emissions by 57.60 % and 22.62 % by adding pine wood and peanut shell, respectively. Meanwhile, significant spatial variations in Sobs, Shannon, and node numbers (P < 0.05) during manure-only composting became insignificant due to C/N ratio increases. Null model and neutral community model showed that stochasticity strongly drove community assembly in all treatments. Assembly process balancing became spatially consistent under increased C/N ratios, shaping the corresponding reduced spatial heterogeneity in alpha-diversity and networks. The variation patterns of spatial heterogeneity in Sobs, node numbers, and dispersal limitation ratios were similar to that of cumulative ammonia emission decreasing with increasing C/N ratio. Additionally, cumulative ammonia emission was positively associated with spatial heterogeneity in Sobs (R 2 = 0.49, P < 0.05) and dispersal limitation ratios (R 2 = 0.53, P < 0.05), while the heterogeneity explained 60.33 % of ammonia variations. This study demonstrated that reduced bacterial spatial heterogeneity was associated with ammonia emission reductions under increased C/N ratios. The improved understanding of bacterial spatial heterogeneity during composting will provide a new perspective for indicating and regulating ammonia emissions. [Display omitted] • N conversion and bacterial communities varied spatially within compost piles. • C/N ratio increases reduced bacterial spatial heterogeneity in compost piles. • Bacterial communities were related to N conversion at different locations in piles. • Reduced bacterial spatial heterogeneity was linked to decreased NH 3 emissions. • Spatially diverse Sobs and community assembly explained 60.33 % of NH 3 variations. [ABSTRACT FROM AUTHOR]

• Soil N balance was estimated by a Canadian agricultural nitrogen budget for reactive N model from 1981 to 2016. • Surplus N in the soil increased from 2.5 to 14.5 kg N ha−1 from 1981 to 2016. • The N 2 O and NH 3 emissions increased over a 36-year period due to increased fertilizer N inputs. • The N 2 O, NH 3 emissions and NO 3 −leaching accounted for 1.2, 6.0 and 6.3 % of total N input in 2016. • The N use efficiency increased from 51.8 to 72.5 % in 2001–2016 contributed by the improvement of N uptake. Agriculture is a major source of reactive nitrogen (Nr) losses through ammonia (NH 3) volatilization, nitrous oxide (N 2 O) emissions and nitrate (NO 3 −) leaching. A Canadian Agricultural Nitrogen Budget for Reactive N (CANBNr) model was developed to estimate the nitrogen (N) balance in soils, including N removals by harvested crops and Nr losses for the years 1981–2016 across Canada. Annual N inputs to farmland include commercial fertilizer N, livestock manure N, symbiotic and asymbiotic biological N fixation and atmospheric N deposition of NO x and NH 3. The total annual N input for Canadian farmland was 5528 Gg N (103.2 kg N ha−1) in 2016 where N removal by crops and Nr accounted for 72.5 % (74.9 kg N ha−1) and 13.4 % (13.9 kg N ha−1), respectively. The Nr losses from N 2 O emissions, NH 3 volatilization and NO 3 − leaching accounted for 64 Gg N (1.2 kg N ha−1), 330 Gg N (6.2 kg N ha−1) and 348 Gg N (6.5 kg N ha−1), which represents between1.2–6.3 % of total N input. A total of 777 Gg N (14.5 kg N ha−1) remained in the soil as surplus N (14.1 % of total N input), which could be available to subsequent crops in dryer regions but might be subject to N 2 O loss through nitrification or denitrification processes or NO 3 − leaching following heavy rains in humid regions. Nitrous oxide and ammonia emissions increased over a 36-year period due to increased fertilizer N inputs. The percentage of N inputs that was estimated to be lost as Nr increased from 17.9 % in 1981 to the peak level of 19.8 % in 2001 and then declined to 13.4 % in 2016. Total N removal by crops increased at a greater rate than N input during the 2001–2016 period resulting in an increased N uptake by crops over the last 15 years. The improved management of fertilizer N for agricultural systems represents a key opportunity for both farmers and policy makers to further reduce Nr losses from Canadian farmland without negatively impacting productivity. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)