|Baumhardt, Roland - Louis|
Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/1/2007
Publication Date: 11/1/2007
Citation: Baumhardt, R.L., Staggenborg, S.A., Gowda, P., Colaizzi, P.D., Howell, T.A. 2007. Evaluating irrigation management strategies to maximize cotton yield and water use efficiency: A simulation analysis [abstract]. ASA-CSSA-SSSA Annual Meeting, November 4-8, 2007, New Orleans, Louisiana. 2007 CDROM.
Technical Abstract: Increasing pumping costs and declining well capacities in the Texas High Plains compel producers to adapt irrigation strategies for maximum crop yield and water use efficiency (WUE)(ratio yield to evapotranspiration, ET), using applications that vary between none (i.e., dryland production) and complete replacement of crop ET. Cotton [Gossypium hirsutum (L.)] is a crop suited to both dryland and various deficit irrigation production systems. Our objectives were to (1) evaluate irrigation frequency, capacity, and duration effects on cotton, and (2) compare irrigation water allocation strategies that maximize yield and WUE. Using GOSSYM and long-term (1959-2000) weather records from Bushland, TX, we simulated lint yields of a stripper cotton cultivar grown in rows 0.76 m apart and with 13 plants m-2 on an adequately fertilized Pullman soil (fine, mixed, superactive, and thermic Torrertic Paleustoll). All possible combinations of irrigation frequency (4, 7, 10 – days between applications), application capacity (0.0, 2.5, 3.75, and 5.0 mm d-1), and duration (4, 6, 8, and 10 weeks beginning 37 days after emergence) were compared with the SAS general linear model procedures according to a factorial arrangement of a completely randomized design. Our results show that simulated cotton lint yield decreased with increasing irrigation frequency or decreasing amount. Simulated lint yield for common net irrigation amounts increased with increasing irrigation capacity. We conclude that spreading water to uniformly irrigate a field with 2.5 mm d-1 produces ~ 5 percent less lint than concentrating the same water resources to variably irrigate a field at 3.75 or 5.0 mm d-1with complementary (2:1 and 1:1) dryland areas.