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ARS Home » Midwest Area » Ames, Iowa » National Laboratory for Agriculture and The Environment » Soil, Water & Air Resources Research » Research » Publications at this Location » Publication #321471

Title: Evapotranspiration and assimilation flux measurements in a corn-soybean rotation system and a reconstructed prairie using a portable canopy chamber

item WANG, ZHUANGJI - Iowa State University
item LUO, CHENYI - Iowa State University
item CARR, BENJAMIN - Iowa State University
item Sauer, Thomas
item HELMERS, MATTHEW - Iowa State University
item HORTON, ROBERT - Iowa State University

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 9/18/2015
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Measurement of Evapotranspiration (ET) and carbon dioxide assimilation flux (AF) is valuable for agricultural management, where ET indicates plant water use, and AF relates to photosynthesis and plant production. Portable canopy chambers were developed for directly measuring of ET and AF fluxes in various cropping systems. Seasonal patterns of chamber measured ET and AF fluxes have not yet been fully studied. The objective of this study was to quantify seasonal ET and AF fluxes in corn, soybean and reconstructed prairie. This research was performed at the Comparison of Bio-fuel Systems (COBS) research site near Ames, IA. Canopy chambers were used to measure ET and AF fluxes in the different cropping systems. Three different chamber heights were used to match crop heights during different crop growth periods. During the 2014 growing season, diurnal measurements were performed approximately once a week. Data from 15 measurement days were obtained. The chamber measured ET and AF fluxes in prairie were the largest in the early growing season, and the ET and AF fluxes in corn were the largest in the late growing season. The pattern of ET for the three crops was correlated to the pattern of AF. The chamber measured ET and AF fluxes were consistent with the eddy covariance measurements. In summary, the portable canopy chamber appears to be a reliable method for measuring ET and AF fluxes in the field.