Measurements of ammonia emission from grazed grassland.
Environ Pollut
; 65(4): 333-46, 1990.
Article
em En
| MEDLINE
| ID: mdl-15092257
ABSTRACT
Some of the factors influencing NH(3) emission from grazed grassland were examined. The large day-to-day variation in rates of loss were only partially explained by variation in the measured environmental factors (wind speed, soil and air temperature, soil moisture status, relative humidity, rainfall and potential evapotranspiration). Of the measured variables, wind speed had the largest effect but the best multiple linear regression model of daily NH(3) loss had an adjusted R(2) value of only 0.406. The mechanisms controlling NH(3) flux were therefore unclear. There were marked diurnal rhythms in NH(3) loss and the concentration gradients above the sward were strongest during the period which included the 3 h each side of midday. This pattern of NH(3) release has important implications in relation to atmospheric mixing processes and chemical reactions. A comparison of two means of determining NH(3) concentrations, i.e. a bubbler collection system or denuder tubes, indicated that different forms were collected which could be related to the environmental conditions. Such differences and effects should be considered when models are developed to describe the behaviour of nitrogenous and other species in the atmosphere.
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Base de dados:
MEDLINE
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Environ Pollut
Assunto da revista:
SAUDE AMBIENTAL
Ano de publicação:
1990
Tipo de documento:
Article
País de afiliação:
Reino Unido