Abatement Of Ammonia Emissions Research Articles

Assessment of ammonia distribution in a livestock farm using CFD simulations

Livestock farming is a significant source of ammonia emissions, which can have adverse effects on human health and the environment. Understanding the distribution and dispersion of ammonia within a livestock farm is crucial for developing effective mitigation strategies. In this study, computational fluid dynamics (CFD) simulations were employed to assess the spatial distribution of ammonia within a representative livestock farm. A detailed 3D model of the farm was created, incorporating the structural layout and ventilation systems. The CFD simulations were conducted using an approach validated by several other researcher groups, considering factors such as ammonia release rate, temperature, and ventilation rates. The results of the CFD simulations provided valuable insights into the distribution patterns of ammonia within the farm. The concentration contours revealed areas of high ammonia concentration, highlighting potential hotspots and vulnerable locations. To investigate the effect of air velocity and temperature on ammonia convection and to save electricity cost, the duty cycle was determined using transient analysis. We have studied the costs and benefits of agricultural ammonia emission abatement options for compliance with air quality regulations. The simulations allowed for the evaluation of different ventilation rates to mitigate ammonia concentration. The findings contribute to the understanding of ammonia emission sources and provide valuable guidance for the design and optimization of livestock farming systems, enabling the development of sustainable practices that mitigate the environmental impact of ammonia emissions.

Association of PM2.5 from agriculture sources and acute myocardial infarction onset: results from 2015 to 2018 in China

Background and purpose: Acute myocardial infarction (AMI) is a manifestation of coronary artery disease. Fine particulate matter (PM2.5) has been regarded as a risk factor for AMI-related mortality and hospitalizations. Agricultural activities contribute greatly to PM2.5 formation, indicating potential health risks of PM2.5 in agricultural areas. Health effect studies on agricultural source remain scarce, and currently available evidence is controversial. This study investigated the health effects of short-term exposure to PM2.5 from agricultural sources on AMI onset using a nationwide analysis in China. Methods: We reviewed case records from the China Cardiovascular Association Database and extracted the data of 355,815 patients with AMI onset from 1,653 hospitals for the period 2015 to 2018. We obtained daily concentrations of PM2.5 from agricultural sources using the source-oriented Community Multiscale Air Quality model. Moreover, we proposed a time-stratified case-crossover study to examine associations between exposure to PM2.5 from agricultural sources and AMI onset and determined lag effects with a maximum of 3 days. Additionally, we conducted multiple subgroup and sensitivity analyses. Results: Exposure to PM2.5 caused a significantly increased risk of the onset of AMI and its subtypes. Short-term exposure to PM2.5 from agricultural sources on the current day (lag 0) was positively associated with a 4.4% (95% confidence interval [95% CI]: 3.3%–5.5%), 4.9% (95% CI: 3.5%–6.3%), and 3.4% (95% CI: 1.5%–5.4%) increase in the odds of AMI, ST-elevation myocardial infarction (STEMI), and non-STEMI (NSTEMI), for each 10 μg/m3 increase. Meanwhile, higher risk estimations were pronounced in individuals who were aged above 65 years, who lived in southern China, and who resided in the rural area setting, and significant differences were mostly found in NSTEMI onsets. Conclusions: Short-term exposure to PM2.5 from agricultural sources may trigger the onset of AMI and its two subtypes. Improving agriculture management through ammonia emission abatement can help in achieving PM2.5 reduction and protecting public health.

Increasing importance of ammonia emission abatement in PM2.5 pollution control

Increasing importance of ammonia emission abatement in PM2.5 pollution control

Incentivising ammonia emission abatement through in-house slurry acidification: Evidence from a discrete choice experiment in Germany

This article assesses farmers' willingness to participate in a stylised scheme supporting the adoption of slurry acidification techniques in livestock facilities. Slurry acidification is a novel technique, developed in Denmark, to reduce ammonia emissions. In a discrete choice survey of 129 German livestock farmers, the respondents were asked to choose among different support schemes and the status quo. The attributes presented in the choice sets were the expected emission reduction, the cost share on offer, a factor by which the additional nitrogen in acidified slurry must be accounted for in fertiliser plans, and concessions on current fertiliser regulations. A mixed logit model showed that the majority of respondents valued emission reductions, a higher cost share and concessions on the statutory requirements of the Fertiliser Ordinance. A latent-class model was applied to reveal preference heterogeneity. It identified three preference classes with different perceptions of the scheme's attributes.

A novel approach to estimate the abatement of ammonia emissions from mitigation techniques at farm-scale slurry stores exemplified by a semifloating cover.

Ammonia (NH3 ) losses from livestock slurry stores substantially contribute to agricultural emissions to the atmosphere. Gas release from slurry storage facilities is driven by interactions between store operations and meteorological conditions. This study quantifies the abating effect of an impermeable semifloating cover as an emission mitigation technique at a farm-scale slurry storage tank. Emissions were measured over 1 yr and compared with the preceding 2 yr of measurements with the uncovered tank. In this novel approach, emission data were aggregated to categories within 1 h measuring intervals according to five key factors influencing emissions (time span after agitation and tank-filling level as surrogates for natural crust occurrence; the meteorological parameters precipitation, air temperature, and wind speed) for the two consecutive measurement campaigns with and without the cover. The emission abatement effect of the cover was determined by emission modeling of the entire measuring campaign based on measuring intervals of the uncovered and the covered tank where the aggregated categories of influencing factors were equal. The resulting average emission abatement was 48%. An average abatement of 37 and 54% was achieved during periods with and without a surface crust, respectively. The emission reduction was less with low tank filling level due to higher air exchange through openings of the cover. The presented approach is applicable to evaluate emission mitigation techniques for single farm-scale stores. With adequate measurement duration, it is appropriate to produce reliable emission data reflecting the complex interactions between emissions and influencing factors occurring at real-world storage facilities.

A review of biotechnologies for the abatement of ammonia emissions

Ammonia emissions are found in a wide range of facilities such as wastewater treatment plants, composting plants, pig houses, as well as the fertilizer, food and metallurgy industries. Effective management of these emissions is important for minimizing the detrimental effects they can have on health and the environment. Physical-chemical (thermal oxidation, absorption, catalytic oxidation, etc.) treatments are the most common techniques for the abatement of ammonia emissions. However, the requirement for more eco-friendly techniques has increased interest in biological alternatives. Accordingly, several bio-based process configurations (biofilters, biotrickling filters and bioscrubbers) have been reported for ammonia abatement in a wide spectrum of conditions. Due to ammonia is a highly soluble compound, bioscrubber seems to be the best option for ammonia abatement. However, this technology is still not widely studied. The proper managements of the ammonia bio-oxidation sub-products is a key parameter for the correct operation of the process. The aim of this review is to critically examine the biotechnologies currently used for the treatment of ammonia gas emissions highlighting the pros and cons of each technology. The key parameters for each configuration used in both full-scale and lab-scale bioreactors are analyzed and summarized according to previous publications.

Ammonia emission abatement does not fully control reduced forms of nitrogen deposition

Human activities and population growth have increased the natural burden of reactive nitrogen (N) in the environment. Excessive N deposition on Earth's surface leads to adverse feedbacks on ecosystems and humans. Similar to that of air pollution, emission control is recognized as an efficient means to control acid deposition. Control of nitrogen oxides (NOx = NO + NO2) emissions has led to reduction in deposition of oxidized nitrogen (NOy, the sum of all oxidized nitrogen species, except nitrous oxide [N2O]). Reduced forms of nitrogen (NHx = ammonia [NH3] + ammonium [NH4+]) deposition have, otherwise, increased, offsetting the benefit of reduction in NOy deposition. Stringent control of NH3 emissions is being considered. In this study, we assess the response of N deposition to N emission control on continental regions. We show that significant reduction of NHx deposition is unlikely to be achieved at the early stages of implementing NH3 emission abatement. Per-unit NH3 emission abatement is shown to result in only 60-80% reduction in NHx deposition, which is significantly lower than the demonstrated 80-120% benefit of controlling NOx emissions on NOy deposition. This 60-80% effectiveness of NHx deposition reduction per unit NH3 emission abatement reflects, in part, the effects of simultaneous reductions in NOx and SO2 emissions.

Costs and benefits of agricultural ammonia emission abatement options for compliance with European air quality regulations

BackgroundIn Europe, ammonia (NH3) emissions strongly contribute to fine particulate matter (PM2.5) pollution and associated premature human mortality. The National Emission Ceilings Directive 2016/2284/EU has set an obligation for all European Union countries to reduce the NH3 emissions by 6%, relative to 2005, by 2020. This study aims to assess the costs and benefits of four NH3 emission abatement options for the compliance of the agricultural sector with the commitments of the European air quality regulatory framework. A regional atmospheric model (WRF/Chem) was used to assess the effects of regulating NH3 emissions reductions on PM2.5 concentrations over Europe. Non-market valuation techniques (value of statistical life) were used to monetize the associated health outcomes.ResultsWe calculated that 16 out of the 28 EU member states exceeded their 2020 NH3 emission ceilings in 2016. The highest exceedances from the 2020 emission commitment level occurred in Latvia (15%), Germany (12%) and the UK (12%). Simulation of the required NH3 emission reduction by WRF/Chem showed that relatively large reductions in PM2.5 concentrations occur over central-western Europe and the UK. The largest health benefits (> 5% reduction in premature mortality) were found for Scandinavia. The economic benefit from avoided premature deaths over Europe amounts to 14,837 M€/year. The costs of four NH3 emission abatement options, where each would fully achieve the required emission reduction, range from 80 M€/year for low nitrogen feed to 3738 M€/year for low-emission animal housing, with covered manure storage (236 M€/year) and urea fertilizer application (253 M€/year), in between.ConclusionOur analysis indicates that the costs of compliance by the agricultural sector with the commitments of the European air quality regulations are much lower than the economic benefit. Thus, much more ambitious reduction commitments for NH3 emissions could be applied by the EU-28. The monetization of the health benefits of NH3 emission abatement policies and the assessment of the implementation costs can help policy-makers devise effective air pollution control programmes.

Abatement of ammonia emissions from dairy cow house concrete floor surfaces through additive application

Winter housing of dairy cows and beef cattle is common practise in north-western European countries such as the UK and Ireland. In cattle housing, urine and dung are deposited over a large floor surface area from which ammonia (NH3) emissions may rapidly occur. The application of additives to this emitting layer has the potential to significantly reduce NH3 volatilisation from cattle housing surfaces. A dynamic flow-through chamber based study was carried out to determine the NH3 abatement potential of 10 additives applied to dairy cow slurry covered concrete surfaces under simulated northwest European winter housing conditions. Peak NH3 fluxes for control (slurry only) treatments occurred at approximately 3–5 h post slurry application, peaking at 133 mg [NH3–N] m−2 h−1. Acidifiers offered the most potential for cost-effectively abating NH3 emissions from slurry-fouled surfaces by increasing the NH4+:NH3 ratio. Experimental data suggests that targeting a slurry pH of 6 at the housing floor stage can significantly reduce NH3 emissions from fresh excreta. Of the tested additives, alum was the most successful at abating NH3 emissions from slurry; particularly after 6 h (76% NH3 abatement), where the efficacy of alum was greatest relative to the other acidifiers. Alum was followed by calcium chloride (69%) and sulphuric acid (41%). Actisan, a commercially available bedding disinfectant was another successful NH3 abatement option (59% after 6 h). Caution is needed in extrapolating results from this chamber-scale study to cow house scale as spatial and temporal variability of excreta deposition and climatic factors create additional complexity.

Abatement of ammonia emissions from livestock housing fine-tuned according to impact on protected habitats

Livestock farms are an important source of ammonia emissions, which threaten vulnerable habitats and species in nearby natural areas through a process of atmospheric nitrogen deposition. An integrated and spatially-explicit mixed integer programming model was applied to all livestock facilities in Flanders (Belgium), to evaluate the current Flemish policies aimed at limiting ammonia deposition in Natura 2000 sites. The simulations indicate that a substantial reduction in deposition is achievable with a similar cost to the currently applied policy in Flanders. Furthermore, the model allows identification of the most suitable stable type and emission abatement measures for any stable in Flanders. Such a spatially-explicit optimization approach applied to individual emission sources might assist policymakers in improving spatially-differentiated policies.

Estimating health and economic benefits of reductions in air pollution from agriculture

Agricultural ammonia emissions strongly contribute to fine particulate air pollution (PM2.5) with significant impacts on human health, contributing to mortality. We used model calculated emission scenarios to examine the health and economic benefits accrued by reducing agricultural emissions. We applied the “value of statistical life” metric to monetize the associated health outcomes. Our analysis indicates that a 50% reduction in agricultural emissions could prevent >200 thousand deaths per year in the 59 countries included in our study, notably in Europe, Russia, Turkey, the US, Canada and China, accompanied with economic benefits of many billions US$. In the European Union (EU) mortality could be reduced by 18% with an annual economic benefit of 89 billion US$. A theoretical complete phase-out of agricultural emissions could lead to a reduction in PM2.5 related mortality of >50% plus associated economic costs in 42 out of the 59 countries studied. Within the EU, 140 thousand deaths could be prevented per year with an associated economic benefit of about 407billionUS$/year. A cost-benefit assessment of ammonia emission abatement options for the EU indicates that the reduction of agricultural emissions generates net financial and social benefits. The monetization of the health benefits of air pollution abatement policies and the costs of implementation can help devise cost-effective air quality management strategies.

Assessing ammonia emission abatement measures in agriculture: Farmers' costs and society's benefits – A case study for Lower Saxony, Germany

Ammonia (NH3) emissions have adverse impacts on the environment and, being a precursor for fine particulate matter, also on human health. About 95% of NH3 emissions in Germany originate from agriculture, mainly from livestock husbandry. This case study is aimed at presenting an approach that evaluates NH3 emission abatement measures in agriculture regarding their abatement costs for farmers and their benefits for the society in terms of avoided external costs of health damages and loss of terrestrial biodiversity. Following the impact-pathway chain, an economic-ecological farm model for estimating NH3 emission reductions and abatement costs was combined with an environmental impact assessment model for estimating the benefits for human health and biodiversity. The case study analysed a variety of manure storage cover and application techniques in Lower Saxony, a region in the north-west of Germany with the highest livestock density in Germany and high NH3 emissions. In the reference situation, the damage costs of NH3 emissions were EUR 2.7 billion. The implementation of concrete storage covers and slurry injection, the most effective measures, reduced NH3 emissions by 25% and achieved net benefits of EUR 505 million. Farmers' abatement costs averaged over all farms ranged from EUR 3.6 to 6.8 per kilogramme NH3 reduced. The abatement costs per farm type ranged from EUR 2.4 to 16.6 for floating plastic covers and from EUR 2.2 to 11.4 for concrete covers. The abatement costs for floating plastic covers were lower for grazing livestock specialists, while the abatement costs for concrete covers were lower for pig specialists, poultry specialists and mixed farms. Farm type specific abatement costs for manure application techniques ranged from EUR 4.5 to 9.6 per kilogramme NH3 reduced with little variation between trailing shoe and cultivator/injector techniques. Abatement costs for trailing shoe application were lower than for cultivator/injector application for grazing livestock specialists, poultry specialists and mixed farms. The average benefits per kilogramme NH3 reduced were EUR 14.1 for health and EUR 10.4 for biodiversity, totalling EUR 24.5. As the benefits exceed the abatement costs for all measures analysed in this study, principally, they can be recommended for implementation. However, the variation in abatement potentials and costs per farm type indicate differences in suitability. While manure covers should above all be implemented by pig specialists because of their high abatement potential, manure application techniques should be implemented by grazing livestock specialists. Among manure storage covers, floating plastic covers are more favourable for grazing livestock specialists, whereas concrete covers are more suitable for all other farm types. The analysis with the farm model was considered more appropriate than recent analyses at technical or macroeconomic level, because the abatement costs reflect differences in farm types, detailed production processes and farmers' profit-maximising behaviour. Overall, it can be concluded that an assessment of NH3 emission abatement measures should be carried out for farm types and should consider impacts of NH3 emission abatement both on human health and biodiversity. The presented modelling approach enables to estimate abatement costs for farm types and benefits for human health and biodiversity. Cost-efficient NH3 emission abatement measures tailored to farm types can be identified and farm type specific regional abatement strategies can be developed.

A Whole‐Farm Strategy to Reduce Environmental Impacts of Nitrogen

Dutch regulations for ammonia emission require farmers to inject slurry into the soil (shallow) or to apply it in narrow bands at the surface. For one commercial dairy farm in the Netherlands it was hypothesized that its alternative farming strategy, including low-protein feeding and surface spreading, could be an equally effective tool for ammonia emission abatement. The overall objective of the research was to investigate how management at this farm is related to nitrogen (N) losses to the environment, including groundwater and surface water. Gaseous emission of ammonia and greenhouse gasses from the naturally ventilated stables were 8.1 and 3.1 kg yr(-1) AU(-1) on average using the internal tracer (SF(6))-ratio method. Measurements on volatilization of ammonia from slurry application to the field using an integrated horizontal flux method and the micrometeorological mass balance method yielded relatively low values of ammonia emissions per ha (3.5-10.9 kg NH(3)-N ha(-1)). The mean nitrate concentration in the upper ground water was 6.7 mg L(-1) for 2004 and 3.0 mg L(-1) for 2005, and the half-year summer means of N in surface water were 2.3 mg N L(-1) and 3.4 mg N L(-1) for 2004 and 2005, respectively. Using a nutrient budget model for this farm, partly based on these findings, it was found that the calculated ammonia loss per ton milk (range 5.3-7.5 kg N Mg(-1)) is comparable with the estimated ammonia loss of a conventional farm that applies animal slurry using prescribed technologies.

Natural crusting of slurry storage as an abatement measure for ammonia emissions on dairy farms

Research on the incidence and effectiveness of natural crusting on slurry storage as a means of ammonia emission abatement was undertaken in studies at farm-scale, pilot-scale and on a small-scale. At the farm-scale, slurry crusting was found to be commonplace across a large proportion (ca 80%) of slurry storage facilities, despite the fact that regular store mixing and agitation was found to be carried out on 68% of farms. Observations provided information on the impact of a range of factors on the potential for crust formation. The most important factors were slurry solids content (crusting increasing with dry matter (DM) content), volume:surface area ratio of the storage (influencing nature of the crust and rate of formation), livestock diet (crusting more likely with grass silage), slurry management (agitation). Of particular importance, were weather conditions with evaporation increasing crusts and rainfall having the opposite effect. From measurements at farm- and pilot-scale (i.e. excluding small-scale comparative studies), mean ammonia emissions were 1.07 and 3.42 g m −2 d −1 NH 3 -N, for crusted and non-crusted slurry stores, respectively. Where direct comparisons between crusted and non-crusted slurry were possible, a reduction in NH 3 emission of about 60% was typical during the measurement period. Although the range in emission measurements was large, the results reported here have confirmed the potential for significant abatement under practical farm conditions. Assuming that natural crusting is as effective in reducing emissions as these results suggest, an objective assessment of crust integrity needs to be developed to assist with effective implementation of mitigation policy. A type of ‘crustometer’ could be developed, at least partly based on the falling weight technique described and tested briefly within the field studies. The work has also identified potential for a modelling approach for the prediction of crust development and, hence, likely emission abatement efficiency.

Abatement of Ammonia Emissions from Swine Lagoons Using Polymer-Enhanced Solid-Liquid Separation

A study was conducted to determine the effects of solid-liquid separation of liquid swine manure on ammonia emissions from lagoons. This determination was done at full-scale in two contiguous swine production units that had similar animal production management. One of these units was maintained as a control using the anaerobic lagoon treatment method. In the second production unit, solids were removed from liquid manure using an enhanced-polymer solid-liquid separation treatment prior to lagoon storage. The ammonia gas fluxes from both lagoons were measured simultaneously during a 10-month period (Feb.-Nov., 2004) using passive flux samplers. On average, the solid-liquid separation treatment separated 85% of total suspended solids (TSS), 60% of total solids (TS), 73% of chemical oxygen demand (COD), 81% of organic N, and 8% of total ammoniacal N (TAN) from the liquid entering the lagoon. Ammonia emissions from the anaerobic lagoon control totaled 12,542 kg N/yr (13,633 kg N/ha/yr). This compares to lower ammonia emissions of 3,426 kg N/yr (or 3,684 kg N/ha/yr) from the anaerobic lagoon treated with solid-liquid separation. Although water quality changes were modest in the treated lagoon with respect to the control, total annual NH3 emissions abatement in the lagoon with solid-liquid separation was 73% with respect to the anaerobic lagoon control. These results overall demonstrate that solid-liquid separation technologies can substantially reduce ammonia emissions from anaerobic swine lagoons.

Greenhouse gas and ammonia emission abatement by slurry treatment

NH 3, CH 4 and N 2O emissions from dairy cattle and pig slurries were quantified. The effect of the following treatments was investigated: untreated covered slurry, mechanically separated slurry, anaerobically digested slurry, slurry covered with a layer of straw, and slurry aeration. Measurements were carried out with dairy cattle and with pig slurry, in winter and in summer. After storage, slurries were band applied on grassland. NH 3 emissions mainly occurred after field application. Promising mitigation options are low trajectory application techniques and proper timing of application. Anaerobic digestion is an effective means to reduce GHG emissions. Straw cover and slurry aeration showed negative environmental effects and are not recommended.

A low cost solution for ammonia emission abatement from slurry storage

A Leca® balls layer was evaluated for its ability to reduce losses of ammonia from the liquid surface of stored swine manure. An uncovered slurry tank partly embedded in the ground was divided into two halves by a plastic sheet. A 10 cm thick Leca® balls layer was applied to the surface of one half of the slurry tank. Ammonia emission was measured by means of the funnel technique floating on the slurry surface. Ammonia emitted from the Leca® balls covered and uncovered slurry, respectively, was measured simultaneously over time periods of 24 h for 6 consecutive days. Measurements were repeated in each of the four seasons during 1 year. Ammonia emission from the uncovered slurry ranged between 0.98 and 2.68 gNH 3/m 2, whereas from the surface covered with Leca® between 0.25 and 0.35 gNH 3/m 2 were emitted. Results pointed out a significant reduction of ammonia emission (up to 87%) due to the Leca® balls layer, what showed the persistency of this strategy for the whole time period of the trial. A first economic evaluation showed that Leca® results in an increase in slurry management costs of up to 4 Eurocent/m 2.

Possibility of reduction of ammonia emissions from manure storage piles

According to the Gothenburg Protocol to abate acidification, eutrophication and ground-level ozone ammonia emissions need to be reduced by 40% in manure storage systems. An abatement of ammonia emissions, suggested in this paper, is based on application of the biotechnological agent Amalgerol. Ammonia emissions from farmyard manure storage piles from broiler and pig breeding were compared in order to verify the reducing potential of the applied biotechnological agent. The experiments carried out under operating conditions proved a positive influence of biotechnological agents on ammonia emissions reduction – decrease in the emissions from the broiler storage pile represented 41.16% and from the pig storage pile 35.85%, both in comparison with reference storage piles.

Cost-effective strategies for the abatement of ammonia emissions from European agriculture

Anthropogenic emissions of ammonia, primarily from agriculture, have been recognised as a significant contributor to overall nitrogen deposition in Europe and are being incorporated within the development of a new international protocol on total nitrogen emissions aimed at protecting natural ecosystems from acidification and eutrophication. In response, the MARACCAS model has been developed to assess the cost-effectiveness of potential abatement measures, mainly relating to the management of livestock wastes, and to assist in the design of efficient abatement strategies. Results indicate that although maximum feasible reductions in emissions are fairly limited, most of the possible abatement can be achieved at relatively low cost. By analysis of the measures which consistently produce cost-effective emissions reductions, a set of guideline measures has been identified which could provide significant reductions at costs competitive with those for NO x abatement measures. Greater inherent uncertainties in the estimation of ammonia emissions and abatement potential as compared to NO x , and practical obstacles to ensuring compliance suggest that a more flexible ‘soft’ protocol may be more appropriate in tackling ammonia.

Consequences of new scientific findings for future abatement of ammonia emissions

Several studies have shown that the estimated decreases in emissions of ammonia in the Netherlands are overestimated. Results obtained from recent research on the so-called compensation point of ammonia in intensive farming areas, research in areas affected with swine fever, and research on emissions following application, all show that the decrease in emissions of ammonia expected to be achieved by injection of manure into the soil is not obtained when the amount of nitrogen greatly exceeds the crop need. The amount of nitrogen applied to Dutch soils has exceeded crop and grass needs for some years. When this condition continues for a long time it appears that ammonia available in the manure or soil will be emitted from the crop/soil system as the result of changes in the air-soil/vegetation equilibrium. If this hypothesis is true we have to reconsider the current strategies for management of ammonia emissions in intensive farming areas. The emphasis should be on limitations of the total amount of nitrogen applied to soils rather than on increasing the effectiveness of injection of manure. Furthermore, the N-cycle should be considered as a whole and nitrogen management approached should be adjusted so they are optimal for both nitrogen management and crop production efficiency. The technological measures that should be explored include chemical binding of nitrogen in manure or in soil, manure processing on farm level with the emphasis on fixation of ammonium or extraction of ammonia from the manure, combined with further processing into specific fertiliser products, and for de-nitrification to N 2.