Details

Autor(en) / Beteiligte

• Kimball, B.A
• LaMorte, R.L
• Pinter, P.J. Jr
• Wall, G.W
• Hunsaker, D.J
• Adamsen, F.J
• Leavitt, S.W
• Thompson, T.L
• Matthias, A.D
• Brooks, T.J

Titel

Free-air CO2 enrichment and soil nitrogen effects on energy balance and evapotranspiration of wheat

Ist Teil von

• Water resources research, 1999-04, Vol.35 (4), p.1179-1190

Ort / Verlag

Blackwell Publishing Ltd

Erscheinungsjahr

1999

Quelle

Wiley Blackwell Single Titles

Beschreibungen/Notizen

• In order to determine the likely effects of the increasing atmospheric CO2 concentration on future evapotranspiration, ET, plots of field-grown wheat were exposed to concentrations of 550 micromol/mol CO2 (or 200 micromol/mol above current ambient levels of about 360 micromol/mol) using a free-air CO2 enrichment (FACE) facility. Data were collected for four growing seasons at ample water and fertilizer (high N) and for two seasons when soil nitrogen was limited (low N). Measurements were made of net radiation, Rn; soil heat flux; air and soil temperatures; canopy temperature, Ts; and wind speed. Sensible heat flux was calculated from the wind and temperature measurements. ET, that is, latent heat flux, was determined as a residual in the energy balance. The FACE treatment increased daytime Ts about 0.6 degrees and 1.1 degrees C at high and low N, respectively. Daily total Rn was reduced by 1.3% at both levels of N. Daily ET was consistently lower in the FACE plots, by about 6.7% and 19.5% for high and low N, respectively.