Location: Soil and Water Management ResearchTitle: Modeled cotton yield response to irrigation and El Nino Southern Oscillation phases for thermally limited growing seasons of western Kansas
|Baumhardt, Roland - Louis|
|HAAG, LUCAS - Kansas State University|
|LAMM, FREDDIE - Kansas State University|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/20/2021
Publication Date: 11/7/2021
Citation: Baumhardt, R.L., Haag, L.A., Gowda, P.H., Schwartz, R.C., Marek, G.W., Lamm, F.R. 2021. Modeled cotton yield response to irrigation and El Nino Southern Oscillation phases for thermally limited growing seasons of western Kansas [abstract]. ASA-CSSA-SSSA International Annual Meeting (Virtual), November 7-10, 2021, in Salt Lake City, UT. Paper No. 139201.
Technical Abstract: Annual precipitation in the western Great Plains provides from 40% to 80% of potential crop evapotranspiration (ETc) and necessitates irrigation to meet crop water demand, using water from the Ogallala aquifer, which is practically non-recharging south of Nebraska. Continued pumping of the aquifer has drawn down water tables and reduced water availability, increasing reliance on precipitation, deficit irrigation, or an alternate crop like cotton (Gossypium hirsutum L.) with reduced water demand than corn (Zea mays L.). Precipitation in parts of the Great Plains varies with the El Niño Southern oscillation (ENSO) climatic phenomenon, which is related to the monitored equatorial sea surface temperatures. Our objective was to compare simulated cotton yield response to irrigation capacity and application period during each of the ENSO phases at three western Kansas locations with different growing season energy. Using actual 1961-2000 location weather records and the crop growth simulation model GOSSYM, we estimated yields of cotton emerging on DOY-145 from soil at 50% plant-available water for all combinations of irrigation periods (0, 4, 6, 8, and 10 weeks after first square) and capacities (2.5, 3.75, and 5.0 mm/d). The ENSO phase had no significant effect on growing season energy at any location, but precipitation was significantly lower during La Niña at the southernmost location which depressed simulated lint yields. Yield and its ratio to crop evapotranspiration (ETc) or water productivity consistently decreased as location elevation or latitude increased due to reduced growing season energy. Depending on location, simulated cotton lint consistently increased (p = 0.05) for scenarios with increasing irrigation capacity due to greater early season boll load. Irrigation durations exceeding 4 to 6 weeks did not increase yield because later fruit did not mature. Cotton WUE increased with early high-capacity irrigation that promoted vigorous growth and fruiting forms for timely maturation.