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The main objectives of this review were to: (1) review different methods/techniques to assess gaseous N-losses from manure (2) review N-gaps, attributed to dinitrogen loss as the difference between directly measured N compounds summed as total N loss and indirectly measured N loss through a mass balance in livestock manure systems, and (3) provide approaches to close the N-gap. In literature, N-gaps run up to 80% of total N loss, this undermines N emission assessments and leaves a huge part of the emission unexplained. However, studies that measure N-gaps are scarcely available or are limited in their evaluation, hence more study is needed. Three approaches are introduced to research N-gaps: (1) measure N2 through a suggested Gas Flow Soil Core (GFSC) technique and compare the sum of all measured N losses with the indirect method, (2) assume N2 loss as being the N-gap and (3) include N2 as an estimate based on ratios from literature. In a hypothetical example for poultry manure, assumed values for measurement error of 50% and variance due to physical differences between the experimental units of 50% led to a total standard deviation of 131% in the N-gap. Variance of N-gap was reduced with 80% point when assuming 16 vessels compared to single vessel. Using literature-based-ratios to estimate losses of N compounds led to variation of N-gap from 0.06% initial N overestimation to 26% of initial N underestimation. Future research should address this variance and apply methods to measure N2 to close N-gaps.

Livestock manure management systems can be significant sources of nitrous oxide (N 2O), methane (CH 4), and ammonia (NH 3) emissions. Many studies have been conducted to improve our understanding of the emission processes and to identify influential variables in order to develop mitigation techniques adapted to each manure management step (animal housing, outdoor storage, and manure spreading to land). The international project DATAMAN (http://www.dataman.co.nz) aims to develop a global database on greenhouse gases (N 2O, CH 4) and NH 3 emissions from the manure management chain to refine emission factors (EFs) for national greenhouse gas and NH 3 inventories. This paper describes the housing and outdoor storage components of this database. Relevant information for different animal categories, manure types, livestock buildings, outdoor storage, and climatic conditions was collated from published peer reviewed research, conference papers, and existing databases published between 1995 and 2021. In the housing database, 2024 EFs were collated (63% for NH 3, 19.5% for CH 4, and 17.5% for N 2O). The storage database contains 654 NH 3 EFs from 16 countries, 243 CH 4 EFs from 13 countries, and 421 N 2O EFs from 17 countries. Across all gases, dairy cattle and swine production in temperate climate zones are the most represented animal and climate categories. As for the housing database, the number of EFs for the tropical climate zone is under-represented. The DATAMAN database can be used for the refinement of national inventories and better assessment of the cost-effectiveness of a range of mitigation strategies.

This chapter gathers information about the current legal requirements related to the emission of ammonia from animal housing in 24 out of the 27 EU countries and in 7 non-EU countries. Overall, the chapter shows that most of the included countries have established substantial procedures to limit ammonia emission and practically no procedures to limit greenhouse gas emission. The review can also be seen as an introduction to the substantial initiatives and decisions taken by the EU in relation to ammonia emission from animal housing, and as a notification on the absence of corresponding initiatives and decisions in relation to greenhouse gases. An EU directive on industrial emissions from 2010 and an implementation decision from 2017 are the main general instruments to reduce ammonia emission from animal housing in the EU.

Emissions of ammonia (NH3), nitrous oxide (N2O) and methane (CH4) from livestock production may be measured for different reasons and in consequence reported in a wide range of units. For the purpo...

European dairy production faces significant economic, environmental, and social sustainability challenges. Given the great diversity of dairy cattle production systems in Europe, region-specific concepts to improve environmental and socioeconomic sustainability are needed. Regionally integrated dairy cattle-crop systems emerge as a more resilient and sustainable alternative to highly specialized farming systems. Identifying different dairy cattle production typologies and their potential interactions with fodder crop production is presented as a step in transitioning to optimized agricultural systems. Currently existing typologies of integrated systems are often insufficient when characterizing structural, socioeconomic, and environmental components of farms. We fill this gap in the literature by identifying, describing, and comparing representative dairy cattle production system typologies and their interrelation with regional fodder crop production at the European regional scale. This is a necessary step to assess the scope for adapted mitigation and sustainability measures in the future. For this purpose, a multivariate statistical approach is applied. We show how different land-use practices, farm structure characteristics, socio-economic attributes, and emission intensities condition dairy production. Furthermore, the diversity of regional fodder crop production systems is demonstrated by analyzing their distribution in Europe. Together with identified typologies, varying degrees of regional specialization in milk production allow for identifying future strategies associated with the application of integrated systems in key European dairy regions. This study contributes to a better understanding of the existing milk production diversity in Europe and their relationship with regional fodder crop production. In addition, we discuss the benefits of integrated systems as a clear, viable, and resilient alternative to ongoing livestock intensification in the European context. Identifying interactions between components of integrated systems will facilitate decision-making, the design and implementation of measures to mitigate climate change, and the promotion of positive socio-economic and environmental interactions.

Livestock production contributes to releasing methane into the atmosphere. Liquid manure management offers significant opportunities to reduce these emissions. A better understanding of the factors controlling methane emissions from manure is necessary to select effective mitigation strategies. Our study aimed to identify the influence of storage temperature and the associated change in chemical composition on methane emissions from dairy and fattening pig manure. Storage temperature affects microbial activity and induces changes in chemical composition that are key influences in methane emissions. Dairy and fattening pig manure samples were stored at five different temperatures (5–25 °C) for 90 days in a laboratory-scale experiment to measure the methane production. The chemical composition of the slurry samples was analyzed, and the biochemical methane potential (BMP) tests were performed before and after storage. For pig manure stored at 25 °C and 20 °C, methane emissions accounted for 69.3% and 50.3% of the BMP, respectively. Maximum methane emissions for dairy slurry were observed at 25 °C but remained at a low level. Analyses of the accumulation of volatile fatty acids (VFAs) during storage are presented in few studies, this work revealed a potential inhibition of methane production, where the accumulation of VFAs was most elevated in samples stored at 20 °C and 25 °C. This partly counteracted the increase in methane emissions expected from the higher temperatures. The degree of VFA and dissociated fatty acids accumulation in dairy cattle slurry should be assessed for more accurate estimations of methane emissions from slurry stores.

Nitrous oxide (N2O), ammonia (NH3), and methane (CH4) emissions from the manure management chain of livestock production systems are important contributors to greenhouse gases (GHGs) and NH3 emitted by human activities. Several studies have evaluated manure-related emissions and associated key variables at regional, national, or continental scales. However, there have been few studies focusing on the drivers of these emissions using a global dataset. An international project was created (DATAMAN) to develop a global database on GHG and NH3 emissions from the manure management chain (housing, storage, and field) to identify key variables influencing emissions and ultimately to refine emission factors (EFs) for future national GHG inventories and NH3 emission reporting. This paper describes the “field” database that focuses on N2O and NH3 EFs from land-applied manure and excreta deposited by grazing livestock. We collated relevant information (EFs, manure characteristics, soil properties, and climatic conditions) from published peer-reviewed research, conference papers, and existing databases. The database, containing 5,632 observations compiled from 184 studies, was relatively evenly split between N2O and NH3 (56 and 44% of the EF values, respectively). The N2O data were derived from studies conducted in 21 countries on five continents, with New Zealand, the United Kingdom, Kenya, and Brazil representing 86% of the data. The NH3 data originated from studies conducted in 17 countries on four continents, with the United Kingdom, Denmark, Canada, and The Netherlands representing 79% of the data. Wet temperate climates represented 90% of the total database. The DATAMAN field database is available at http://www.dataman.co.nz.

Concepts of material flow and mass consistency of nitrogen compounds have been used to elucidate nitrogen’s fate in an urban environment. While reactive nitrogen commonly is associated to agriculture and hence to large areas, here we have compiled scientific literature on nitrogen budget approaches in cities, following the central role cities have in anthropogenic activities generally. This included studies that specifically dealt with individual sectors as well as budgets covering all inputs and outputs to and from a city across all sectors and media. In the available data set, a clear focus on Asian cities was noted, making full use of limited information and thus enable to quantitatively describe a local pollution situation. Time series comparisons helped to identify trends, but comparison between cities was hampered by a lack of harmonized methodologies. Some standardization, or at least improved reference to relevant standardized data collection along international norms was considered helpful. Analysis of results available pointed to the following aspects that would reveal additional benchmarks for urban nitrogen budgets: analysing the share of nitrogen that is recycled or reused, separating largely independent sets of nitrogen flows specifically between food nitrogen streams and fossil fuel combustion-related flows, and estimating the stock changes for the whole domain or within individual pools.

Manure application to land and deposition of urine and dung by grazing animals are major sources of ammonia (NH3 ) and nitrous oxide (N2 O) emissions. Using data on NH3 and N2 O emissions following land-applied manures and excreta deposited during grazing, emission factors (EFs) disaggregated by climate zone were developed, and the effects of mitigation strategies were evaluated. The NH3 data represent emissions from cattle and swine manures in temperate wet climates, and the N2 O data include cattle, sheep, and swine manure emissions in temperate wet/dry and tropical wet/dry climates. The NH3 EFs for broadcast cattle solid manure and slurry were 0.03 and 0.24 kg NH3 -N kg-1 total N (TN), respectively, whereas the NH3 EF of broadcast swine slurry was 0.29. Emissions from both cattle and swine slurry were reduced between 46 and 62% with low-emissions application methods. Land application of cattle and swine manure in wet climates had EFs of 0.005 and 0.011 kg N2 O-N kg-1 TN, respectively, whereas in dry climates the EF for cattle manure was 0.0031. The N2 O EFs for cattle urine and dung in wet climates were 0.0095 and 0.002 kg N2 O-N kg-1 TN, respectively, which were three times greater than for dry climates. The N2 O EFs for sheep urine and dung in wet climates were 0.0043 and 0.0005, respectively. The use of nitrification inhibitors reduced emissions in swine manure, cattle urine/dung, and sheep urine by 45-63%. These enhanced EFs can improve national inventories; however, more data from poorly represented regions (e.g., Asia, Africa, South America) are needed.

The air change rate (ACR) of naturally ventilated dairy buildings (NVDBs) plays an important part in the design and control of the ventilation system, as well as in the estimation of the gaseous emission rate. The objectives of this research were to model the ACR based on a quantitative investigation of the relationship between the ACR and its potential influencing factors, including the opening ratio (r), the building length to width ratio (α), the wind speed (U), and the wind direction (θ). The investigations were performed using the response surface methodology integrated with the Box-Behnken design and Computational Fluid Dynamics (CFD) simulations. Three response surface models of the ACR of NVDBs were established for three opening ratio ranges of 5%–42.5%, 42.5%–80%, and 5%–80%, respectively. It was found that the selection of the opening ratio range had almost no effect on the developed response surface models. The results showed that the ACR of NVDBs was not influenced by α, but was significantly affected by r, U, θ, and interaction effects between every two of the three factors. The highest ACR was 6.7 s−1, 6.0 s−1, and 4.0 s−1 when θ, U, and r was at their respective medium value while the rest parameters were at the highest values, indicating that the r played an important role in the value of ACR. It was concluded that in the prediction of the ACR of a building, the influences of both individual and interactional effects of θ, U, and r should be considered.

Gaseous emissions from livestock buildings have been a research focus for many years. In particular, quantifying emissions from naturally ventilated buildings is not trivial because it requires accurately determining the air exchange rate (AER) and representative gaseous concentration values in the exhaust and in the incoming air. Improvements are required for the method for estimating AERs and for selecting representative sampling points and locations in naturally ventilated dairy buildings (NVB). The objective of this study was to investigate the magnitude and sources of uncertainties in calculating AERs. A long-term experiment was performed in an NVB located in north-east Germany. CO 2 concentrations were continuously measured inside the barn at eight uniformly distributed points and outside the barn at four points. Sensitivity studies on the calculation of AER were performed by varying the indoor and outdoor sampling points, sampling duration and animal parameters used for the calculation. The sensitivity results were compared to the best available data approximation (BADA), which is based on the best knowledge of these parameters. All factors were evaluated and ordered in terms of their influence on AER calculation and uncertainty. The results show that the sampling duration and the number and location of indoor sampling points have the largest effects on AER uncertainty. Data on milk yield and days since insemination have the lowest influence on AER uncertainty. The information collected in this long-term study is very important for planning measurement campaigns in the future.

In recent years, the problem of the welfare and heat load of dairy cows has become increasingly important in moderate climate zones. The objective of the present study was to determine heat load thresholds of average daily temperature-humidity index (THI) that lead to changes in different activity traits of lactating high-yielding dairy cows. Furthermore, we studied how the activity of the cows to heat load was influenced by the daily heat load duration which exceeded the heat load we had determined as threshold in our experiments. The study was conducted from June 2015 to May 2017 in a naturally ventilated dairy barn in Gros Kreutz, Germany. The climate was measured at several positions inside the barn, and the average THI was calculated every 10 min. The THI was used to define the dairy cows’ heat load exposure. In addition, the activity of the cows was measured by pedometers, and different activity traits were recorded in the functional groups "resting behavior" and "locomotion behavior”. The heat load thresholds determined by broken-stick models were 47 THI (standing bout duration, number of steps) as well as 67 THI (total lying/standing time, number of lying/standing bouts, lying bout duration). During the experimental period, the most reliable heat load threshold of 67 THI was exceeded from May to September for up to 480 h per month. The analysis model of each activity trait included the effect of the average daily THI values below and above the determined heat load threshold and the effect of the daily heat load duration exceeding the determined heat load threshold. The total lying/standing time and the number of steps showed significant changes related to increasing daily heat load duration. The effect of the daily heat load duration additionally intensified the effect of the average daily THI.

Atmospheric NOx concentrations are declining steadily due to successful abatement strategies predominantly targeting combustion sources. On the European continent, total NOx emissions fell by 55% between 1990 and 2017, but only modest reductions were achieved from the agricultural sector; with 7.8% from 20 Eastern European countries and 19.1% from 22 Western European countries. Consequently, the share of agricultural NOx emissions for these 42 European countries have increased from 3.6% to 7.2%. These values are highly uncertain due to serious lack of studies from agricultural soils and manure management. The emission factor (EFNO 1.33%), currently used for calculating soil NOx emissions from European agricultural categories 'N applied to soils' and 'manure management' was evaluated here by including recently published data from temperate climate zones. The newly calculated EFNO (average 0.60%, 0.0625th%/0.5475th%, n = 65 studies) is not notably different from the current value, given the large uncertainties associated with the small pool of studies, and therefore continued use of EFNO (1.33%) is recommended until more data become available. An assessment of the contribution of agricultural and non-agricultural NOx sources found that of the 42 European countries, the 8 most populated countries achieved considerable reductions (1990-2017) from categories 'non-agricultural sources' (55%), 'N applied to soils' (43%) and 'manure management' (1.2%), compared to small reductions from the remaining 34 countries. Forests are also large sources of soil NOx. On average, emissions from Eastern European forests were 4 times larger than from 'N applied agricultural soil', whereas Western European NOx emissions from 'N applied agricultural soil' were two times larger than from forest soils. Given that non-agricultural sources of NOx continue to decline, soil related emissions from agriculture, forests and manure management become more important, and require rigorous investigation in order to improve atmospheric pollution forecasts.

[EN] Milk production in Europe is facing major challenges to ensure its economic, environmental, and social sustainability. It is essential that holistic concepts are developed to ensure the future sustainability of the sector and to assist farmers and stakeholders in making knowledge-based decisions. In this study, integrated sustainability assessment by means of whole-farm modelling is presented as a valuable approach for identifying factors and mechanisms that could be used to improve the three pillars (3Ps) of sustainability in the context of an increasing awareness of economic profitability, social well-being, and environmental impacts of dairy production systems (DPS). This work aims (i) to create an evaluation framework that enables quantitative analysis of the level of integration of 3P sustainability indicators in whole-farm models and (ii) to test this method. Therefore, an evaluation framework consisting of 35 indicators distributed across the 3Ps of sustainability was used to evaluate three whole-farm models. Overall, the models integrated at least 40% of the proposed indicators. Different results were obtained for each sustainability pillar by each evaluated model. Higher scores were obtained for the environmental pillar, followed by the economic and the social pillars. In conclusion, this evaluation framework was found to be an effective tool that allows potential users to choose among whole-farm models depending on their needs. Pathways for further model development that may be used to integrate the 3P sustainability assessment of DPS in a more complete and detailed way were identified., This study was financially supported by the German Federal Ministry of Food and Agriculture (BMEL) through the Federal Office for Agriculture and Food (BLE) under grant number 2819ERA08A (MilKey project, funded under the Joint Call 2018 ERA-GAS, SusAn and ICT-AGRI 2 on Novel technologies, solutions and systems to reduce the greenhouse gas emissions in animal production systems). BC3-Research is supported by the Spanish Government through María de Maeztu excellence accreditation 2018-2022 (Ref. MDM-2017-0714) and by the Basque Government through the BERC 2018¿2021 program. Agustin del Prado is financed through the Ramon y Cajal program by the Spanish Ministry of Economy, Industry, and Competitiveness (RYC-2017-22143).

Along with industry and transportation, agriculture is one of the main sources of primary particulate matter (PM) emissions worldwide. Bioaerosol formation and PM release during livestock manure field application and the associated threats to environmental and human health are rarely investigated. In the temperate climate zone, field fertilization with manure seasonally contributes to local PM air pollution regularly twice per year (spring and autumn). Measurements in a wind tunnel, in the field and computational fluid dynamics (CFD) simulations were performed to analyze PM aerosolization during poultry manure application and the influence of manure moisture content and treatment. A positive correlation between manure dry matter content (DM) and PM release was observed. Therefore, treatments strongly increasing the DM of poultry manure should be avoided. However, high manure DM led to reduced microbial abundance and, therefore, to a lower risk of environmental pathogen dispersion. Considering the findings of PM and microbial measurements, the optimal poultry manure DM range for field fertilization was identified as 50–70%. Maximum PM10 concentrations of approx. 10 mg per m3 of air were measured during the spreading of dried manure (DM 80%), a concentration that is classified as strongly harmful. The modeling of PM aerosolization processes indicated a low health risk beyond a distance of 400 m from the manure application source. The detailed knowledge about PM aerosolization during manure field application was improved with this study, enabling manure management optimization for lower PM aerosolization and pathogenic release into the environment.

This chapter reviews sustainable nitrogen management for housed livestock, manure storage and manure processing. The chapter begins by discussing the various forms nitrogen can take, focusing specifically on ammonia, nitrous oxide and di-nitrogen. It then goes on to review livestock feeding and housing for dairy and beef cattle, pigs and poultry. The chapter also examines manure storage, treatment and processing by discussing the principles of emissions produced from these processes as well as mitigation measures that can be used. It also addresses the best practices and priority measures for livestock feeding, housing and manure storage, treatment and processing.

Nitrous oxide (N2O) is a long-lived greenhouse gas that contributes to global warming. Emissions of N2O mainly stem from agricultural soils. This review highlights the principal factors from peer-reviewed literature affecting N2O emissions from agricultural soils, by grouping the factors into three categories: environmental, management and measurement. Within these categories, each impact factor is explained in detail and its influence on N2O emissions from the soil is summarized. It is also shown how each impact factor influences other impact factors. Process-based simulation models used for estimating N2O emissions are reviewed regarding their ability to consider the impact factors in simulating N2O. The model strengths and weaknesses in simulating N2O emissions from managed soils are summarized. Finally, three selected process-based simulation models (Daily Century (DAYCENT), DeNitrification-DeComposition (DNDC), and Soil and Water Assessment Tool (SWAT)) are discussed that are widely used to simulate N2O emissions from cropping systems. Their ability to simulate N2O emissions is evaluated by describing the model components that are relevant to N2O processes and their representation in the model.

Airflow inside naturally ventilated dairy (NVD) buildings is highly variable and difficult to understand due to the lack of precious measuring techniques with the existing methods. Computational fluid dynamics (CFD) was applied to investigate the effect of different seasonal opening combinations of an NVD building on airflow patterns and airflow rate inside the NVD building as an alternative to full scale and scale model experiments. ANSYS 2019R2 was used for creating model geometry, meshing, and simulation. Eight ventilation opening combinations and 10 different reference air velocities were used for the series of simulation. The data measured in a large boundary layer wind tunnel using a 1:100 scale model of the NVD building was used for CFD model validation. The results show that CFD using standard k-&epsilon, turbulence model was capable of simulating airflow in and outside of the NVD building. Airflow patterns were different for different opening scenarios at the same external wind speed, which may affect cow comfort and gaseous emissions. Guiding inlet air by controlling openings may ensure animal comfort and minimize emissions. Non-isothermal and transient simulations of NVD buildings should be carried out for better understanding of airflow patterns.

Methane emissions from livestock manure are primary contributors to GHG emissions from agriculture and options for their mitigation must be found. This paper presents the results of a study on methane emissions from stored liquid dairy cow manure during summer and winter storage periods. Manure from the summer and winter season was stored under controlled conditions in barrels at ambient temperature to simulate manure storage conditions. Methane emissions from the manure samples from the winter season were measured in two time periods: 0 to 69 and 0 to 139 days. For the summer storage period, the experiments covered four time periods: from 0 to 70, 0 to 138, 0 to 209, and 0 to 279 continuous days, with probing every 10 weeks. Additionally, at the end of all storage experiments, samples were placed into eudiometer batch digesters, and their methane emissions were measured at 20 degrees C for another 60 days to investigate the potential effect of the aging of the liquid manure on its methane emissions. The experiment showed that the methane emissions from manure stored in summer were considerably higher than those from manure stored in winter. CH4 production started after approximately one month, reaching values of 0.061 kg CH4 kg(-1) Volatile Solid (VS) and achieving high total emissions of 0.148 kg CH4 kg(-1) VS (40 weeks). In winter, the highest emissions level was 0.0011 kg CH4 kg(-1) VS (20 weeks). The out comes of these experimental measurements can be used to suggest strategies for mitigating methane emissions from manure storage.

Globally, particulate matter (PM) emissions are a growing cause of concern due to the potential impact on human health and environment. The agricultural sector is responsible of the 17% of the total anthropogenic emission of PM10 and the agricultural operations (tilling, harvesting, residue burning etc.) have been recognized as one of the main drivers of this contribution. This topic has been addressed in many articles, focusing on the impacts coming from different steps of the agricultural production system and using different assessment methods. The aim of this review is to identify the main agricultural operations producing particulate emission, providing a collection of the Emission Factors (EF) available in literature. The most used EFs determination methods have also been described, by focusing on pros and cons of each method. Issues and lacks of information to be addressed by future research have been highlighted. It has been observed that very few PM emission assessment have been done by taking into consideration whole cropping systems and the information available is fragmented onto single cropping activities. In addition, very few mitigation measures have been developed so far.

Good soil quality implies the maintenance of properties at levels capable of ensuring an equilibrated and healthy ecosystem, with sustained agricultural production to supply the world population. Climate change, land-use change, and agriculture intensification are causing a decline in soil quality, which in most parts of the world is becoming severe (desertification). Land-use changes, the associated loss of soil organic matter (SOM), and beneficial microbial diversity are major reasons for deteriorating soil fertility and declining agricultural productivity, as well as affecting water, air, and biodiversity. Adaptation towards climate-resilient and climate-smart agriculture is necessary to cope with climate change and extreme events. This requires the following measures: (1) sustainable production (integrated livestock and cropping systems, including agroforestry); (2) increased soil organic matter (SOM) (bio-based and organic fertilizers, crop rotations, crop associations, no-till, conservation agriculture, C sequestration, and microbial processes); (3) reduced greenhouse gas emissions, less nutrient losses from agriculture, and increased nutrient use efficiency (NUE) (precision agriculture).

Emissions and ventilation rates (VRs) in naturally ventilated dairy barns (NVDBs) are usually measured using indirect methods, where the choice of inside and outside sampling locations (i.e. sampling strategy) is crucial. The goal of this study was to quantify the influence of the sampling strategy on the estimation of emissions and VRs. We equipped a NVDB in northern Germany with an extensive measuring setup capable of measuring emissions under all wind conditions. Ammonia (NH3) and carbon dioxide (CO2) concentrations were measured with two Fourier-transform infrared spectrometers. Hourly values for ventilation rates and emissions for ammonia over a period of nearly a year were derived using the CO2 balance method and five different sampling strategies for the acquisition of indoor and outdoor concentrations were applied. When comparing the strategy estimating the highest emission level to the strategy estimating the lowest, the differences in NH3 emissions in winter, transition, and summer season were thorn 26%, thorn 19% and thorn 11%, respectively. For the ventilation rates, the differences were thorn 80%, thorn 94%, and 63% for the winter, transition and summer season, respectively. By accommodating inside/outside concentration measurements around the entire perimeter of the barn instead of a reduced part of the perimeter (aligned to a presumed main wind direction), the amount of available data substantially increased for around 210% for the same monitoring period.

The discharge coefficient (Cd) is a characteristic parameter of an opening, which represents the effect of flow contraction and frictional losses when the flow goes across the opening. It is an important parameter for the ventilation rate determination when using the orifice equation method. The objectives of this study were to investigate the relationship between Cd and its potential influencing factors, i.e. opening ratio (r), building length to width ratio (α), wind speed (U), and wind direction (θ), and to evaluate the sensitivity of each factor on the Cd for naturally ventilated dairy buildings (NVDBs). The investigations were performed using the response surface methodology together with Box-Behnken Design and Computational Fluid Dynamics simulation methods. A second-order polynomial response surface model for the estimation of the discharge coefficient was developed and verified. The results showed that the Cd was significantly affected by the individual factors of r and θ, with more sensitivity to r when r > 42.5%. By contrast, the effects from the individual factors of α and U on Cd were insignificant. In addition, the interaction effects between r and θ, and between α and θ on Cd were also identified. It was concluded that the effects from both individual factors and interactions are required to be considered in the estimation of the opening discharge coefficient for NVDBs.

The experiments comprised three vegetation periods of five sorghum varieties. Novel data on the development of biomass yield, maturity level and biogas production were gained. Dry matter (DM) biomass yield ranged between 15.7 and 20.67 t ha −1 when sorghum was grown as main crop. The variety SOR 4 achieved a methane yield of 6500 m 3 ha −1 . The suitability of different sorghum varieties as summer catch crops was measured and assessed by combining growing degree days (GDD; temperatures > 10 °C) and maturity stage. This paper introduces a correlation of yields in course of the vegetation period with GDD values which enables to transfer yield and economic efficiency predictions from present results to other sites. Sorghum is able to provide high-yields when used as catch crop, whereby an adapted varietal selection is indispensable. The sorghum variety SOR 2 (year2) of 1100 growing degree days (GDD) proofed to be fast ripening and is especially suitable as a summer catch crop. This variety achieved mean DM yields of 12.4 t ha −1 when used as summer catch crop. Within this study crop maturities between 20 and 45% DM were investigated. Within this range, no decrease in specific methane yield with the increase in maturity and DM yield was observed. The three year experimental data also included one year with low precipitation. The statistical analysis did not reveal a significant influence of the precipitation on the biomass yield which confirms the drought resistance of sorghum. This result is especially important in view of adaptation to climate change.

The livestock sector is a major contributor to agricultural greenhouse gas (GHG) and nitrogen (N) emissions and efforts are being made to reduce these emissions. National emission inventories are the main tool for reporting emissions. They have to be consistent, comparable, complete, accurate and transparent. The quality of emission inventories is affected by the reporting methodology, emission factors and knowledge of individual sources. In this paper, we investigate the effects of moving from the 1996 IPCC Guidelines for National Greenhouse Gas Inventories to the 2006 IPCC Guidelines on the emission estimates from the livestock sector. With Austria as a case study, we estimated the emissions according to the two guidelines, revealing marked changes in emission estimates from different source categories resulting from changes in the applied methodology. Overall estimated GHG emissions from the livestock sector decreased when applying the IPCC 2006 methodology, except for emissions from enteric fermentation. Our study revealed shifts in the relative importance of main emission sources. While the share of CH4 emissions from enteric fermentation and manure management increased, the share of N2O emissions from manure management and soils decreased. The most marked decrease was observed for the share of indirect N2O emissions. Our study reveals a strong relationship between the emission inventory methodology and mitigation options as mitigation measures will only be effective for meeting emission reduction targets if their effectiveness can be demonstrated in the national emission inventories. We include an outlook on the 2019 IPCC Refinement and its potential effects on livestock emissions estimates. Emission inventory reports are a potent tool to show the effect of mitigation measures and the methodology prescribed in inventory guidelines will have a distinct effect on the selection of mitigation measures.

Soil temperatures from 1976 to 2010 are reported from two sites: Compton (UK) and Hohe Warte (Austria). Soil temperature at Compton significantly increased over the period 1976–2010; increases ranged between +0.04 degC and +0.08 degC year–1, depending on depth. Temperature increases were greater in winter. Mean annual temperature at Hohe Warte increased by around 0.03 degC year−1 from 1976 to 2010. Significant temperature increases were recorded at Hohe Warte in summer, but not in winter. These differences were attributed to greater snow cover at Hohe Warte insulating the soil in winter, and to the drier summers at Hohe Warte enabling more rapid soil warming.

Livestock production is important for food security, nutrition, and landscape maintenance, but it is associated with several environmental impacts. To assess the risk and benefits arising from livestock production, transparent and robust indicators are required, such as those offered by life cycle assessment. A central question in such approaches is how environmental burden is allocated to livestock products and to manure that is re-used for agricultural production. To incentivize sustainable use of manure, it should be considered as a co-product as long as it is not disposed of, or wasted, or applied in excess of crop nutrient needs, in which case it should be treated as a waste. This paper proposes a theoretical approach to define nutrient requirements based on nutrient response curves to economic and physical optima and a pragmatic approach based on crop nutrient yield adjusted for nutrient losses to atmosphere and water. Allocation of environmental burden to manure and other livestock products is then based on the nutrient value from manure for crop production using the price of fertilizer nutrients. We illustrate and discuss the proposed method with two case studies., Highlights • New method to value manure for its beneficial effects on crop production is proposed. • Manure can be considered as a co-product in Life Cycle Assessments when applied according to crop nutrient requirements. • The method encourages farmers to use manure sustainably in livestock and crop production systems.

The increasing global demand for food and the environmental effects of reactive nitrogen losses in the food production chain, increase the need for efficient use of nitrogen (N). Of N harvested in agricultural plant products, 80% is used to feed livestock. Because the largest atmospheric loss of reactive nitrogen from livestock production systems is ammonia (NH3), the focus of this paper is on N lost as NH3 during the production of animal protein. The focus of this paper is to understand the key factors explaining differences in Nitrogen Use Efficiency (NUE) of animal production among various European countries. Therefore we developed a conceptual framework to describe the NUE defined as the amount of animal-protein N per N in feed and NH3—N losses in the production of milk, beef, pork, chicken meat and eggs in The Netherlands, Switzerland, United Kingdom, Germany, Austria and Denmark. The framework describes how manure management and animal-related parameters (feed, metabolism) relate to NH3 emissions and NUE. The results showed that the animal product with the lowest NUE had the largest NH3 emissions and vice versa, which agrees with the reciprocal relationship between NUE and NH3 within the conceptual framework. Across animal products for the countries considered, about 20% of the N in feed is lost as NH3. The significant smallest proportion (12%) of NH3—N per unit of Nfeed is from chicken production. The proportions for other products are 17%, 19%, 20% and 22% for milk, pork, eggs and beef respectively. These differences were not significantly different due to the differences among countries. For all countries, NUE was lowest for beef and highest for chicken. The production of 1 kg N in beef required about 5 kg N in feed, of which 1 kg N was lost as NH3—N. For the production of 1 kg N in chicken meat, 2 kg N in feed was required and 0.2 kg was lost as NH3. The production of 1 kg N in milk required 4 kg N in feed with 0.6 kg NH3—N loss, the same as pork and eggs, but those needed 3 and 3.5 kg N in feed per kg N in product respectively. Except for beef, the differences among these European countries were mainly caused by differences in manure management practices and their emission factors, rather than by animal-related factors including feed and digestibility influencing the excreted amount of ammoniacal N (TAN). For beef, both aspects caused important differences. Based on the results, we encourage the expression of N losses as per N in feed or per N in product, in addition to per animal place, when comparing production efficiency and NUE. We consider that disaggregating emission factors into a diet/animal effect and a manure management effect would improve the basis for comparing national NH3 emission inventories., Graphical abstract Image 1, Highlights • A theoretical framework describes NH3—N loss and NUE related to animal protein production instead of to raw product. • Animal protein in chicken meat had the highest NUE and the lowest NH3—N losses; the reverse was true for beef. • Differences in NUE and NH3—N losses between countries are mainly explained by manure management. • For beef production differences in manure management and TAN production are both relevant. • Presenting additional metrics than N-lost per animal place would enable a more informed comparison of production systems.

[EN] In the last decades, a global warming trend was observed. Along with the temperature increase, modifications in the humidity and wind regime amplify the regional and local impacts on livestock husbandry. Direct impacts include the occurrence of climatic stress conditions. In Europe, cows are economically highly relevant and are mainly kept in naturally ventilated buildings that are most susceptible to climate change. The high-yielding cows are particularly vulnerable to heat stress. Modifications in housing management are the main measures taken to improve the ability of livestock to cope with these conditions. Measures are typically taken in direct reaction to uncomfortable conditions instead of in anticipation of a long-term risk for climatic stress. Measures that balance welfare, environmental and economic issues are barely investigated in the context of climate change and are thus almost not available for commercial farms. Quantitative analysis of the climate change impacts on animal welfare and linked economic and environmental factors is rare. Therefore, we used a numerical modeling approach to estimate the future heat stress risk in such dairy cattle husbandry systems. The indoor climate was monitored inside three reference barns in central Europe and the Mediterranean regions. An artificial neuronal network (ANN) was trained to relate the outdoor weather conditions provided by official meteorological weather stations to the measured indoor microclimate. Subsequently, this ANN model was driven by an ensemble of regional climate model projections with three different greenhouse gas concentration scenarios. For the evaluation of the heat stress risk, we considered the number and duration of heat stress events. Based on the changes in the heat stress events, various economic and environmental impacts were estimated. The impacts of the projected increase in heat stress risk varied among the barns due to different locations and designs as well as the anticipated climate change (considering different climate models and future greenhouse gas concentrations). There was an overall increasing trend in number and duration of heat stress events. At the end of the century, the number of annual stress events can be expected to increase by up to 2000, while the average duration of the events increases by up to 22 h compared to the end of the last century. This implies strong impacts on economics, environment and animal welfare and an urgent need for mid-term adaptation strategies. We anticipated that up to one-tenth of all hours of a year, correspondingly one-third of all days, will be classified as critical heat stress conditions. Due to heat stress, milk yield may decrease by about 2.8 % relative to the present European milk yield, and farmers may expect financial losses in the summer season of about 5.4 % of their monthly income. In addition, an increasing demand for emission reduction measures must be expected, as an emission increase of about 16 Gg of ammonia and 0.1 Gg of methane per year can be expected under the anticipated heat stress conditions. The cattle respiration rate increases by up to 60 %, and the standing time may be prolonged by 1 h. This causes health issues and increases the probability of medical treatments. The various impacts imply feedback loops in the climate system which are presently underexplored. Hence, future in-depth studies on the different impacts and adaptation options at different stress levels are highly recommended., This research has been supported by the German Federal Ministry of Food and Agriculture (BMEL) through the Federal Office for Agriculture and Food (BLE) (grant nos. 2814ERA02C and 2814ERA03C), the Instituto Nacional de Investigacion Tecnologia Agraria y Alimentaria (INIA) (grant no. 618105), the Basque Government (grant no. BERC 2018-2021), the Spanish Ministry of Economy, Industry and Competitiveness MINECO (grant nos. MDM-2017-0714, FJCI-2016-30263, and RYC-2017-22143), and the Innovation Foundation Denmark (grant no. 4215-00004B).

This review gathers information about the current legal requirements related to the emission of ammonia and greenhouse gases from animal housing in 21 out of the 28 EU countries and in 5 non-EU countries. Overall the review shows that most of the included countries have established substantial procedures to limit ammonia emission and practically no procedures to limit greenhouse gas emission. The review can also be seen as an introduction to the substantial initiatives and decisions taken by the EU in relation to ammonia emission from animal housing, and as a notification on the absence of corresponding initiatives and decisions in relation to greenhouse gases. An EU directive on industrial emissions from 2010 and an implementation decision from 2017 are the main general instruments to reduce ammonia emission from animal housing in the EU. These treaties put limits to ammonia emissions from installations with more than 2000 places for fattening pigs, with more than 750 places for sows and with more than 40,000 places for poultry. As an example, the upper general limit for fattening pigs is 2.6 kg ammonia per animal place per year. This review indicates that the important animal producing countries in the EU have implemented the EU requirements, and, that only a few countries with a large pig population, in relation to their geographical size, have implemented requirements that are stricter than what is required by the EU.

National emission inventories for UN FCCC reporting estimate regional soil nitrous oxide (N$_{2}$O) fluxes by considering the amount of N input as the only influencing factor for N$_{2}$O emissions. Our aim was to deepen the understanding of N$_{2}$O fluxes from agricultural soils, including region specific soil and climate properties into the estimation of emission to find targeted mitigation measures for the reduction of nitrogen losses and GHG emissions. Within this project, N$_{2}$O emissions and nitrate (NO$_{3}$$^{-}$) leaching were modelled under spatially distinct environmental conditions in two agricultural regions in Austria taking into account region specific soil and climatic properties, management practices and crop rotations. The LandscapeDNDC ecosystem model was used to calculate N$_{2}$O emissions and NO$_{3}$$^{-}$ leaching reflecting different types of vegetation, management operations and crop rotations. In addition, N input and N fluxes were assessed and N$_{2}$O emissions were calculated. This approach allowed identifying hot spots of N$_{2}$O emissions. Results show that certain combinations of soil type, weather conditions, crop and management can lead to high emissions. Mean values ranged from 0.15 to 1.29 kg N$_{2}$O–N ha$^{-1}$ year$^{-1}$ (Marchfeld) and 0.26 to 0.52 kg N$_{2}$O–N ha$^{-1}$ year$^{-1}$ (Grieskirchen). Nitrate leaching, which strongly dominated N-losses, often reacted opposite to N$_{2}$O emissions. Larger quantities of NO$_{3}$$^{-}$ were lost during years of higher precipitation, especially if winter barley was cultivated on sandy soils. Taking into account the detected hot spots of N$_{2}$O emissions and NO$_{3}$$^{-}$ leaching most efficient measures can be addressed to mitigate environmental impacts while maximising crop production.

Treatment of liquid manure and other wastes by anaerobic digestion (AD) adds to renewable energy targets, and it is thus a favorable strategy for greenhouse gas (GHG) mitigation. Both untreated manure and digestates are typically stored for a period in order to recycle nutrients for crop production, and emissions of methane (CH4), nitrous oxide (N2O) and ammonia (NH3) during storage contribute to the overall GHG balance. We determined emissions of all three gases during summer and autumn storage of digestates and untreated manure in pilot-scale experiments. Using these and other data, GHG balances were calculated for treatment, post-treatment storage, and field application. The GHG mitigation potential of AD was demonstrated, but CH4 emissions during storage dominated the overall GHG balance irrespective of treatment; hence for GHG inventories and mitigation efforts, the correct estimation of this source is critical. Current inventory guidelines from the Intergovernmental Panel on Climate Change (IPCC) estimate CH4 emissions from manure management based on a simple classification of livestock production systems, volatile solids (VS) excreted, and annual average temperature, and the effects of treatment and management at farm level are therefore not accounted for in any detail. Two empirical models were evaluated, which instead calculate VS degradation and storage temperature with daily time steps; both models were based on concepts presented by Sommer et al. (2004) . Parameters for the Arrhenius temperature relationship of CH4 production, i.e., apparent activation energy, Ea, and pre-exponential factor, A, could be selected, for which cumulative CH4 emissions calculated with the two models approached observed emissions. However, the magnitude of emissions during a warm period was not well reproduced, and the parameters identified for the two models differed. Sensitivity analyses showed that deviations from observations could not be explained by errors in manure storage temperature. The results thus suggest that CH4 emissions cannot be predicted from VS and temperature alone, i.e., that the methanogenic potential changes during storage. Determination of parameters for estimation of CH4 emissions from manure management is discussed with reference to recent literature.

This study assesses abatement costs of three measures aimed at reducing nitrogen (N) emissions from livestock production: two protein-adjusted feeding strategies for pigs, and higher-quality forage for dairy cattle. In a partial cost approach, we quantified the effect of different measures on N losses and production costs. We accounted for emissions of NH3, N2O and NO from animal housing, manure storage, manure application, and from soils. Uncertainties related to volatile prices and assumptions about excretion rates and emission factors were assessed in a Monte Carlo simulation. Covering variability of individual input parameters, this uncertainty assessment addresses a fundamental gap in current decision support on N loss reduction measures. For the scenarios investigated, average N abatement costs at farm level were negative and represented net benefits to farmers: In pig husbandry, adapting feeding practices in most individual situations resulted in net benefits, both for three-phase feeding (min −35, max +5, mean −14 €/kg N abated) and optimised single-phase feeding (min −52, max +4, mean −21 €/kg N abated). In dairy production, N abatement by improved forage quality proved invariably more economic than current practice (min −40, max −11, mean −21 €/kg N abated). As shown in this study, N abatement costs can serve as a framework for comparing the cost-effectiveness and feasibility of N loss reduction measures within and between livestock production systems. This is in turn critical when informing practitioners and providing policy support on workable strategies for reducing the N footprint of animal husbandry.