Dynamics of CO2 fluxes and evapotranspiration in till and no-till canola

Authors: MANJUNATHA, PRIYANKA - Oklahoma State University; Wagle, Pradeep; Gowda, Prasanna; Northup, Brian; ROCATELI, ALEX - Oklahoma State University; TAGHVAEIAN, SALEH - Oklahoma State University; Turner, Kenneth

Submitted to: Grazinglands Research Laboratory Miscellaneous Publication
Publication Type: Proceedings
Publication Acceptance Date: 4/17/2018
Publication Date: N/A
Citation: N/A

Interpretive Summary: Abstract only

Technical Abstract: As canola (Brassica napus L.) acreages are expanding for cooking oil and economically viable crop rotations, it is very vital to have better understanding of carbon and evapotranspiration (ET) dynamics of this crop. The eddy flux measurements were taken from the beginning of the growing season of canola (November 2016) through next planting (October 2017). Daily ET reached up to 6.1 and 5.2 mm d-1 at conventional tillage (CT) and no till (NT) canola during the growing season, and 5.4 mm d-1 (CT) and 4.0 mm d-1 (NT) during the fallow period. Daily magnitude of net ecosystem CO2 exchange (NEE) reached up to -8.6 and -5.7 g C m-2. Ecosystem water use efficiency (EWUE) for the growing season was 3.8 and 3.9 g C mm-1 ET, respectively, for CT and NT fields. The CT field was a net carbon sink for 6 months, while NT appeared to be net carbon sink for 4 months. Cumulative ET during the growing season was similar between tillage systems, but fallow period cumulative ET was substantially lower in NT (249 mm) than in CT field (305 mm). Long-term measurements will provide more insights on the influence on tillage practices on carbon and ET dynamics of canola.