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ARS Home » Plains Area » Temple, Texas » Grassland Soil and Water Research Laboratory » Research » Publications at this Location » Publication #340076

Title: Impact of climate change adaptation strategies on winter wheat and cropping system performance across precipitation gradients in the inland Pacific Northwest, USA

Author
item MAAZ, TAI - Washington State University
item SCHILLINGER, WILLIAM - Washington State University
item MACHADO, STEPHEN - Oregon State University
item BROOKS, ERIN - University Of Idaho
item PORT, LAUREN - Washington State University
item Young, Francis
item LESLIE, IAN - Washington State University
item GLOVER, AYANNA - Washington State University
item MADSEN, ISAAC - Washington State University
item MAYNARD-JOHNSON, JODI - University Of Idaho
item Collins, Harold
item PAN, WILLIAM - Washington State University

Submitted to: Frontiers in Ecology and Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/1/2017
Publication Date: 5/29/2017
Publication URL: https://handle.nal.usda.gov/10113/5700696
Citation: Maaz, T., Schillinger, W., Machado, S., Brooks, E., Port, L., Young, F.L., Leslie, I., Glover, A., Madsen, I., Maynard-Johnson, J., Collins, H.P., Pan, W. 2017. Impact of climate change adaptation strategies on winter wheat and cropping system performance across precipitation gradients in the inland Pacific Northwest, USA. FRONTIERS IN ENVIRONMENTAL SCIENCE. 5(23):1-19. doi:10.3389/fenvs.2017.00023.

Interpretive Summary: Crop intensification, diversification, reduced tillage, and variable N management are among strategies proposed to mitigate and adapt to climate shifts in the inland Pacific Northwest (iPNW). Our first objective was to characterize winter wheat (WW)productivity across the precipitation gradient in the iPNW. The second objective was to evaluate winter wheat and cropping system productivity and efficiencies across the iPNW upon (1) fallow replacement, (2) crop diversity, and (3) soil conservation practices, with a particular focus on low precipitation conditions. Our region-wide analysis indicated that WW yields increased with increasing annual precipitation and declined when not adjusted for available water holding capacity. Fallow periods were effective at mitigating low nitrogen fertilization efficiencies under low precipitation, efficiencies declined as annual precipitation increased. Cropping system productivity was not affected by intensification, diversification, or conservation tillage.

Technical Abstract: Ecological instability and low resource use efficiencies are concerns for the long-term productivity of conventional cereal monoculture systems, particularly those threatened by projected climate change. Crop intensification, diversification, reduced tillage, and variable N management are among strategies proposed to mitigate and adapt to climate shifts in the inland Pacific Northwest (iPNW). Our first objective was to characterize winter wheat (WW) (Triticum aestivum L.) productivity across the precipitation gradient in the iPNW. The second objective was to evaluate winter wheat and cropping system productivity and efficiencies across the iPNW upon (1) fallow replacement, (2) crop diversity, and (3) soil conservation practices, with a particular focus on low precipitation conditions. Our region-wide analysis indicated that WW yields increased with increasing annual precipitation, prior to maximizing at 521 mm yr-1 and subsequently declining when not adjusted for available water holding capacity. While fallow periods were effective at mitigating low nitrogen (N) fertilization efficiencies under low precipitation, efficiencies declined as annual precipitation exceeded 480 mm yr-1. We observed considerable variability in WW yields among locations and within sites in response to annual precipitation and N fertilization, indicating that precision N management is warranted across the region. Winter wheat yields declined when following crops rather than summer fallow in years receiving less than 350 mm precipitation yr-1. Nevertheless, WW yields increased across a range of yield potentials when following pulses and oilseeds rather than wheat, and when under conservation tillage practices at low yield potentials. Despite the yield penalty associated with eliminating fallow prior to WW, cropping system level productivity was not affected by intensification, diversification, or conservation tillage.