Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: March 4, 2002
Publication Date: June 15, 2002
Citation: Wall, G.W., Kimball, B.A., Adamsen, F.J., Pinter Jr, P.J., Wechsung, G., Wechsung, F., Kartschall, T., Leavitt, S.W. 2002. Elevated atmospheric carbon dioxide affects root dimensions of spring wheat. Agronomy Abstracts. CD Rom A03-Kimball50553-P.
Field-grown spring wheat (Triticum aestivum L. cv. Yecora Rojo) was exposed to atmospheric carbon dioxide concentrations enriched up to 200 umol/mol above ambient (i.e., 370 umol/mol) using a free-air CO2 enrichment (FACE) apparatus (main plot). Two experiments lasting two years were performed. The first was conducted at ample nitrogen levels and wet (W) and dry (D) irrigation(I) regimes of 100 and 50% replacement of evapotranspiration, respectively. The second two-year study was conducted split plot at ample soil water content, but high (H) and low (L) nitrogen levels of 350 and either 70 or 15 kg N/ha, respectively. Root length density (RLD: km/m), average diameter (RD: mm) and the resultant cylindrical surface area (RSA: m2/ m3) were determined to a vertical depth of 1 m at 3-leaf, tillering, stem-elongation, anthesis, grain filling and harvest. Elevated carbon dioxide in combination with either I or N stress improved root dimensions, thereby causing greater proliferation of the root system in the soil profile. A more robust root system for wheat grown under elevated carbon dioxide concentration increased its capacity to mine soil moisture and nutrients.