Influence of different agricultural practices (type of crop

Enregistrement scientifique n° 993
Symposium n° 26
Présentation : oral
Influence of different agricultural practices (type of crop form of N-fertilizer) on soil N2O emissions
Influence de différentes pratiques agricoles (culture, forme
de fertilisant) sur les émissions de N2O par le sol
HÉNAULT Catherine
(1)
Claude
(1)
, DEVIS Xavier
(1)
, LUCAS Jean Louis(2), GERMON Jean
(1)
INRA - Centre de Microbiologie du Sol et de l’Environnement, 17 rue Sully, 21034 Dijon
Cedex - France
(2)
CETIOM - Station expérimentale, route de Dallas, 21000 Dijon St Appolinaire - France
Nitrous oxide emissions were periodically measured using the chamber method over a one
year period in a cultivated field subjected to different agricultural practices including the type
of Nitrogen fertiliser (ammonitrate, ammonium sulfate, urea or potassium nitrate) and the
type of cultivated plant (rapeseed and winter wheat). Nitrous oxide emissions exhibited the
same seasonal pattern whatever the treatment with emissions between 1.5 to 15 g N ha-1 d-1
during the autumn, 16 to 56 g N ha-1 d-1 in winter after an important period of freezing, 0.5 to
70 g N ha-1 d-1 during the spring and lower emissions during the summer. The type of
cultivated plant had little impact on the level of nitrous oxide emission. These emissions were
a little higher under wheat during the autumn in relation to an higher soil nitrate content but
the level of emissions was similar over a 7 month period (2163 and 2093 g N ha-1 for rape
and wheat respectively). The form of nitrogen fertiliser affected nitrous oxide emissions
during the month following fertiliser application with higher emissions in the case of
ammonitrate and ammonium sulfate and a different temporal pattern of emissions after urea
application. The part of applied nitrogen lost as N2O varied from 0.42 to 0.55 % with the
form of nitrogen applied suggesting that the control of this agricultural factor would not be
efficient in limiting nitrous oxide emissions under certain climatic and pedological situations.
Keywords : nitrous oxide emissions, soil chamber method, nitrogen fertiliser types, wheat,
rapeseed crop.
Mots clés : Emissions, oxyde nitreux, enceintes statiques, fertilisant azoté, blé, colza.