Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 23, 2000
Publication Date: November 9, 2000
Citation: Wechsung, G., Wall, G.W., Kimball, B.A., Pinter Jr, P.J., Adamsen, F.J., Hunsaker, D.J., Lamorte, R.L., Wechsung, F. 2000. Effects of free-air co2 enrichment on root growth of wheat. Agronomy Abstracts. pp 31.
The response of a wheat crop root system to full-season CO2 enrichment was investigated using a Free-Air CO2 Enrichment (FACE) apparatus. Spring wheat (Triticum aestivum L. cv. Yecora Rojo) was grown under two atmospheric CO2 concentrations [CO2], FACE: ~550 [my]mol/mol; Control: ~370 [my]mol/mol in combination with two water treatments [Wet: 100% and Dry: 50% replacement of evapotranspiration]. Total biomass of living roots increased under CO2 enrichment (e.g., 1994 in Wet: 29% at three- leaf stage, 40% at stem-elongation, 26% at post-harvest). During vegetative growth maximal differences between FACE and Control occurred at stem elongation with greater significant stimulation of root growth up to 0.8-m soil depth. Root system in FACE during reproductive growth was increased under ample (36% more root mass in FACE than in Control) and limited water supply. However, in latter case the effect was more pronounced (up to 51%). Results from a two-year FACE x Nitrogen study were consistent with those reported herein for the FACE-Wet treatments. Elevated [CO2] in combination with nitrogen stress resulted in greater root dry mass, similar to the CO2 x water stress reactions.