Agron J 1997 Mar-Apr;89(2):279-84
USDA-ARS, North Central Soil Conservation Res. Lab., Morris, MN 56267, USA.
Portable closed chambers provide a valuable tool for measuring crop photosynthesis and evapotranspiration. Typically, the rates of change of CO2 and water vapor concentration are assumed to be constant in the short time required to make the closed-chamber measurement, and a linear regression model is used to estimate the CO2 and H2O fluxes. However, due to the physical and physiological effects the measurement system has on the measured process, assuming a constant rate and using a linear model may underestimate the flux. Read More