WHEAT GRAIN QUALITY AS AFFECTED BY ELEVATED CO2, DROUGHT, AND SOIL NITROGEN

Authors: Kimball, Bruce; Morris, Craig; Pinter Jr, Paul; Wall, Gerard - Gary; Hunsaker, Douglas - Doug; Adamsen, Floyd; LAMORTE, ROBERT - USDA-ARS, USWCL PHOENIX; LEAVITT, S - UNIV OF ARIZONA; THOMPSON, T - UNIV OF ARIZONA; MATTHIAS, A - UNIV OF ARIZONA - MAC

Submitted to: Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/16/2000
Publication Date: 3/15/2001
Citation: Kimball, B.A., Morris, C.F., Pinter Jr, P.J., Wall, G.W., Hunsaker, D.J., Adamsen, F.J., Lamorte, R.L., Leavitt, S.W., Thompson, T.L., Matthias, A.D. 2001. Wheat grain quality as affected by elevated co2, drought, and soil nitrogen. Plant Pathology. 150(2):295-303.

Interpretive Summary: Atmospheric levels of CO2 concentration are increasing, but the likely consequences on wheat grain nutritional and baking quality are largely unknown. Therefore, wheat grain from two free-air (open field) CO2 enrichment (FACE) experiments conducted at ample and limiting levels of irrigation and soil nitrogen (N) fertilizer was subjected to a battery of nutritional and baking quality tests. The limiting-water treatment improved quality slightly, whereas low nitrogen decreased quality drastically, with protein decreasing about 36% and loaf volume about 26%. At ample water and N, high CO2 decreased quality somewhat, whereas it tended to make the deleterious effects of low N worse. Thus, these data suggest that future elevated CO2 concentrations will exacerbate the deleterious effects of low soil nitrogen on grain quality, but with ample fertilizer nitrogen, the effects will be minor. Such information is needed to develop management strategies in the future, which will benefit all consumers of wheat and other grain food and feed products.

Technical Abstract: The likely consequences of the expected future high levels of atmospheric CO2 concentration on wheat grain nutritional and baking quality were determined. The grain for testing came from two free-air CO2 enrichment (FACE) experiments conducted at ample and limiting levels of irrigation and soil nitrogen (N) fertilizer. The limiting-water treatment improved quality slightly, whereas low nitrogen decreased quality drastically, with protein decreasing about 36% and loaf volume about 26%. At ample water and N, high CO2 decreased quality somewhat, whereas it tended to make the deleterious effects of low N worse. Thus, these data suggest that future elevated CO2 concentrations will exacerbate the deleterious effects of low soil nitrogen on grain quality, but with ample fertilizer nitrogen, the effects will be minor. Such information is needed to develop management strategies in the future, which will benefit all consumers of wheat and other grain food and feed products.