Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

A 3-year continuous record on the influence of daytime, season, and fertilizer treatment on methane emission rates from an Italian rice paddy.

Eine 3jährige kontinuierliche Aufnahme über den Einfluß von Tageszeit, Jahreszeit und Düngerbehandlung auf die Methan-Emissionsraten aus einem italienischen Reisfeld
: Holzapfel-Pschorn, A.; Conrad, R.; Rennenberg, H.; Schütz, H.; Seiler, W.

Journal of geophysical research. D, Atmospheres 94 (1989), Nr.16, S.405-416
ISSN: 0148-0227
ISSN: 2169-897X
ISSN: 2169-8996
Fraunhofer IFU; 2002 in Helmholtz-Gesellschaft integriert

CH4 emission rates have been measured in an Italian rice paddy between 1984 and 1986, covering three vegetation periods. For these measurements a fully automated, computerized sampling and analyzing system was developed which allowed the simultaneous determination of CH4 emission rates at 16 different field plots. CH4 emission rates showed strong diurnal and seasonal variations. Diurnal changes correlated with changes in soil temperature. During the season, CH4 emission rates showed a first maximum in May-June before tillering and a second maximum in July during the reproductive stage of the rice plants. In 1985 and 1986 two maxima were observed during summer in addition to the first maximum in the rate of CH4 emission during spring. Application of mineral and/or organic fertilizer strongly influenced the CH4 emission rates, depending on the type, rate, and mode of fertilizer application. Thus the rates decreased by at most 40% and 60% after fertilization by deep incorporation with 200 kg N/ha urea and 200 kg N/ha ammonium sulfate, respectively. Application of 200 kg N/ha calcium cyanamide led to a reduction of the first maximum of CH4 emission but caused the second maximum to increase, the overall result being that the seasonally averaged CH4 emission rate was comparable to that observed in unfertilized fields.