Abstract
Emission of ammonia (NH3) from animal husbandry, and specially from the dairy
sector, contributes significantly to acidification and eutrophication, and affects sensitive natural
areas. In the nineties Monteny (1998) introduced a mechanistic model to understand and predict
the NH3 emissions from cubicle dairy cow houses. Although a limited sensitivity analysis was
carried out, we still lack information that essential for further development of the model. Our aim
is that the model can predict and assess the NH3 emission from dairy cow houses under
practical circumstance.
The objective of this research was 1) to determine the relevance and irrelevance of a limited set
of input factors, and 2) assess options for further development of the model for use in practice.
A full factorial sensitivity analysis was carried out for eight variables related to NH3 emission
from a urine puddle on the floor. Relative importance and R2 of the regression model factors
were determined.
The NH3 emission varied strongly with both high and low emissions. Strongly contributing
process variables were puddle pH, initial urea concentration, urination frequency, puddle depth
and puddle area. We conclude that deviations in these influencing variables lead to large
fluctuations in the NH3 emission, which means that precise quantification of these variables in
practice is essential for accurate predictions. Moreover, the results also show that the model
may be over-parameterized, having several inputs that seem hardly relevant for the level of NH3
emission.
Original language | English |
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Publication status | Published - 2012 |
Event | The Ninth International Livestock Environment Symposium (ILES IX), Valencia, Spain - Duration: 8 Jul 2012 → 12 Jul 2012 |
Conference/symposium
Conference/symposium | The Ninth International Livestock Environment Symposium (ILES IX), Valencia, Spain |
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Period | 8/07/12 → 12/07/12 |
Keywords
- Ammonia emission
- Cow houses
- Dairy cow
- Mechanistic model
- Sensitivity analysis