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- Andersson, Karin, et al.
(author)
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Ammonia emissions from untreated, separated and digested cattle slurry-Effects of slurry type and application strategy on a Swedish clay soil
- 2023
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In: Biosystems Engineering. - : Elsevier BV. - 1537-5110 .- 1537-5129. ; 226, s. 194-208
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Journal article (peer-reviewed)abstract
- Animal slurry contains plant nutrients such as nitrogen (N) that are essential for crop production. Inorganic slurry N is easily volatilised as ammonia after field application, reducing slurry fertiliser value and causing environmental problems. Ammonia emissions can be reduced by lowering slurry pH, rapid infiltration or incorporation of slurry into soil. This study investigated the effect of different combinations of slurry types and application strategies on ammonia emissions. The slurry types tested were untreated cattle slurry (CS), the liquid fraction from mechanical solid-liquid separation of cattle slurry (LF) and biogas digestate based mainly on cattle slurry (BD). The application strategies tested were trailing hoses, trailing shoes, trailing hose application of acidified slurry and slurry injection. Ammonia emissions after slurry application were measured using wind tunnels, with continuous measurements of ammonia concentrations in outgoing air. Comparisons were also made between measured ammonia emissions and emissions predicted by the ALFAM2 model. Cumulative ammonia emissions after 70 h from LF, CS and BD represented 23%, 29% and 32% of total ammoniacal nitrogen (TAN) applied. Trailing shoes and 50 mm deep injection slots reduced ammonia emissions by on average 17% and 37%, respectively, compared with trailing hoses. Slurry acidification resulted in an average reduction in ammonia emissions of 83%. The ALFAM2 model was reasonably accurate in predicting cumulative emissions (70 h). Accuracy in predicting emission dynamics was low in some cases, likely due to differences between wind tunnel measurements and open-air emis-sions and to model error.(c) 2023 The Authors. Published by Elsevier Ltd on behalf of IAgrE. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
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| 2. |
- Andersson, Karin, et al.
(author)
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Effect of exposed surface area on ammonia emissions from untreated, separated, and digested cattle manure
- 2021
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In: Biosystems Engineering. - : Elsevier BV. - 1537-5110 .- 1537-5129. ; 202, s. 66-78
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Journal article (peer-reviewed)abstract
- Ammonia (NH3) emissions from land-applied liquid manure (slurry) contribute to nitrogen deposition, acidification, and formation of fine particles in the atmosphere. Optimal management and field application techniques can reduce emission. A reduction in contact area between the slurry and the atmosphere is expected to reduce NH3 emission. The objectives of this study were to develop a method for quantifying the exposed surface area (ESA) of field-applied slurry over time, and determine the degree to which ESA explains differences in NH3 emission. Two experiments were conducted in which untreated, separated, and digested slurry was applied in bands on two different soils with spring oats stubble. Emission data were obtained from online wind tunnel measurements and slurry characteristics such as surface pH, viscosity, and particle size distribution were measured. The new ESA method relies on fluorescent dye added to the slurry prior to field application, followed by imaging. The results show that the ESA measurements can give new insight into the soil-slurry interactions after manure application, and this may help explain why some types of slurry and application techniques lead to successful abatement under some circumstances, but not under others. Furthermore, a pH-, TAN-, temperature-, and ESA normalised NH3 emission were estimated, helping idetify the effects of infiltration. (c) 2020 IAgrE. Published by Elsevier Ltd. All rights reserved.
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| 3. |
- Delin, Mattias, et al.
(author)
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Ascending evacuation - Walking speed in stairs as a function of height
- 2015
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In: Human Behaviour in fire : 6th International Symposium - 6th International Symposium. - 9780993393303 ; , s. 155-160
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Conference paper (peer-reviewed)abstract
- During ascending evacuation in long stairs, there is reason to believe that factors such as fatigue, and change in human behaviour will influence the possibility of satisfactory evacuation and affect the ascending walking speed. Based on these assumption, a 2-year research project was initiated at Lund University. This paper gives a brief description of the project and highlight some initial findings according ascending walking speed and effects of fatigue.
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| 6. |
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| 7. |
- Delin, Sofia, et al.
(author)
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Effect of nitrogen fertilization on nitrate leaching in relation to grain yield response on loamy sand in Sweden
- 2014
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In: European Journal of Agronomy. - : Elsevier BV. - 1161-0301 .- 1873-7331. ; 52, s. 291-296
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Journal article (peer-reviewed)abstract
- High rates of nitrogen (N) fertilizer may increase N leaching with drainage, especially when there is no further crop response. It is often discussed whether leaching is affected only at levels that no longer give an economic return, or whether reducing fertilization below the economic optimum could reduce leaching further. To study nitrate leaching with different fertilizer N rates (0-135 kg N ha-1) and grain yield responses, field experiments in spring oats were conducted in 2007, 2008 and 2009 on loamy sand in south-west Sweden. Nitrate leaching was determined from nitrate concentrations in soil water sampled with ceramic suction cups and measured discharge at a nearby measuring station. The results showed that nitrate leaching per kg grain produced had its minimum around the economic optimum, here defined as the fertilization level where each extra kg of fertilizer N resulted in a 10 kg increase in grain yield (85% DM). There were no statistically significant differences in leaching between treatments fertilized below this level. However, N leaching was significantly elevated in some of the treatments with higher fertilization rates and the increase in nitrate leaching from increased N fertilization could be described with an exponential function. According to this function, the increase was less than 0.04 kg kg-1 fertilizer N at and below the economic optimum. Above this fertilization level, the nitrate leaching response gradually increased as the yield response ceased and the increase amounted to 0.1 and 0.5 kg kg-1 when the economic optimum was exceeded by 35 and 100 kg N ha-1, respectively. The economic optimum fertilization level depends on the price relationship between grain and fertilizer, which in Sweden can vary between 5:1 and 15:1. In other words, precision fertilization that provides no more or no less than a 10 kg increase in grain yield per kg extra N fertilizer can be optimal for both crop profitability and the environment. To predict this level already at fertilization is a great challenge, and it could be argued that rates should be kept down further to ensure that they are not exceeded due to overestimation of the optimum rate. However, the development of precision agriculture with new tools for prediction may reduce this risk.
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| 8. |
- Delin, Sofia
(author)
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Effects on nitrate leaching of the timing of cattle slurry application to leys
- 2021
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In: Soil Use and Management. - : Wiley. - 0266-0032 .- 1475-2743. ; 37, s. 436-448
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Journal article (peer-reviewed)abstract
- This study compared the effects on nitrate leaching of slurry application to ley in early Autumn (15 September), late Autumn (1 November) and Spring (April) under Swedish growing conditions. In two separate two-year experiments, started in Autumn 2009 and 2010, on a sandy loam soil in south-west Sweden, these three application times were compared with no slurry application in grass-clover and grass swards. Soil water was sampled with ceramic suction cups, and nitrate leaching was calculated from water nitrate concentrations and drain discharge. Plant measurements indicated that, during Autumn, the grass took up at least 20 kg of the 50 kg nitrogen (N) applied with slurry in September. The mineral nitrogen level in the subsoil (30-90 cm) in December was around 2 kg N ha(-1) higher in this treatment. Nitrate leaching was on average 5 and 6 kg N ha(-1) year(-1) higher after early and late Autumn slurry application, respectively, than after Spring application (p < .001), but the difference varied from 0 to 10 kg N ha(-1) year(-1) between experiments and sward types. Nitrate leaching losses in kg N ha(-1) were lower from the grass sward, but higher if related to nitrogen inputs and dry matter yield. These results indicate that Autumn application can increase the risk of nitrate leaching, but that early/late application within Autumn is less important. It is more important to limit the amount of slurry applied in Autumn and to consider other risks of nitrogen losses associated with time of application, such as ammonia emissions.
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| 9. |
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| 10. |
- Delin, Sofia
(author)
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Fertilizer value of nitrogen in hen and broiler manure after application to spring barley using different application timing
- 2011
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In: Soil Use and Management. - : Wiley. - 0266-0032 .- 1475-2743. ; 27, s. 415-426
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Journal article (peer-reviewed)abstract
- The nitrogen (N) fertilizer effect of layer hen and broiler manure applied at different times on spring barley yield was studied in seven Swedish field experiments during 2005-2008. Two experiments had parallel field incubations to study N release after fertilizer application. The effect of total N in manure on N offtake was 30-40% that of mineral N, except in a dry year, when the effect was very low. Although the relative proportions of ammonium N, uric acid N and other N differed between the hen and broiler manure, the effect of total N was similar for both. In field incubations, mineral N decreased from 75 to 60% of total N applied in hen manure, whereas it increased from 20 to 50% in broiler manure, because of net immobilization and release, respectively. The limited fertilizer nitrogen replacement value, corresponding to only 30-40% of total N, could be as a result of ammonia volatilization after rather shallow incorporation with harrow. Net N release from broiler manure lasted for 6-8 weeks after application, after which it generally ceased. In some cases, manure application in early spring gave better yield effects than application at sowing, probably because of better synchronization of the N release with crop N requirements. The residual N effect on the N offtake in crop in the year after manure application was on average 3% of the total N applied, equivalent to a fertilizer replacement value of about 6%.
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