|Baumhardt, Roland - Louis|
|JONES, O.R. - Retired ARS Employee|
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/13/2015
Publication Date: 3/4/2016
Citation: Baumhardt, R.L., Mauget, S.A., Schwartz, R.C., Jones, O. 2016. El Nino southern oscillation effects on dryland crop production in the Texas High Plains. Agronomy Journal. 108(2):1-9. dio:10.2134/agronj2015.0403.
Interpretive Summary: As water for irrigation from the Ogallala Aquifer declines, dryland farming will become a more prevalent land use practice. Adapting practices to long term climate forecast may enable farmers to realize higher yield potentials. Equatorial Pacific sea surface temperatures cause predictable El Nino and La Nina weather patterns in much of North America, which could be used to guide crop management. ARS scientists from Bushland and Lubbock, Texas compared effects on crop growth and yield in a dryland wheat-sorghum-fallow rotation over 58 years according to El Nino and La Nina periods. Wheat growing-season rain and grain yields were greater for El Nino phases than La Nina phase years. Differences in grain sorghum growing season rain and yield were limited. Our results suggest that summer crop management based on El Nino/La Nina phases may be less reliable than for wheat. These results are of interest to farmers and crop consultants as an aid to making strategic decisions regarding future crop practices.
Technical Abstract: Risk adverse dryland crop management in the US Southern High Plains may stabilize year to year productivity, however in some years the full yield potential is unrealized thereby reducing the overall cropping system productivity. Equatorial Pacific sea surface temperature anomalies (SSTA) systematically couple with the atmosphere to produce predictable El Niño-Southern Oscillation (ENSO) weather patterns in much of North America that could be exploited for improved crop water management. Our objective was to evaluate ENSO effects on site-specific growth and yield of wheat (Triticum aestivum L.) and grain sorghum [Sorghum bicolor (L.) Moench] in a dryland wheat-sorghum-fallow (WSF) rotation from 1954 to 2011. Measurements from six contour farmed graded terraces were grouped by common ENSO phase years based on 3-month classification ending in June (AMJ) or August (JJA) that permits timely management of sorghum or wheat. Compared with years classified during mature SON (September to November) ENSO phases, the JJA classification identified 78 and 68 percent of common La Niña and El Niño phase years, respectively, and may have potential application to wheat management. However, poorer agreement for the corresponding AMJ classified ENSO phase years (61 and 53 percent, respectively) limits utility for managing grain sorghum. Wheat growing-season precipitation and detrended grain yields were 31 and 51 percent greater, respectively, for El Nino phase conditions compared with La Nina phase. In contrast, ENSO effects to increase sorghum yield during El Niño phase years, were less pronounced than for wheat, suggesting summer crop water management may be less reliable.