Impacts of variable irrigation regimes on cotton yield and fiber quality

Authors: MASASI, BLESSING - Oklahoma State University; TAGHVAEIAN, S - Oklahoma State University; BOMAN, R - Oklahoma State University; Moriasi, Daniel; Starks, Patrick

Submitted to: Agricultural & Environmental Letters
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/27/2020
Publication Date: 9/30/2020
Citation: Masasi, B., Taghvaeian, S., Boman, R., Moriasi, D.N., Starks, P.J. 2020. Impacts of variable irrigation regimes on cotton yield and fiber quality. Agricultural & Environmental Letters. 5(1):e20031. https://doi.org/10.1002/ael2.20031.
DOI: https://doi.org/10.1002/ael2.20031

Interpretive Summary: Water resources in the cotton-producing areas of Oklahoma have declined due to persistent droughts and severe groundwater extractions for irrigation. We conducted a four-year field study at a commercial field in west-central Oklahoma to evaluate the effects of full irrigation, reduced irrigation at 75% of full irrigation, and no irrigation regimes on cotton yield and fiber quality, and the potential of each regime to conserve water. The results showed minimal yield loss along with improved yield per unit of applied irrigation water when seasonal irrigation amount was reduced by 25% of the full capacity. Conversely, a substantial yield loss was observed under no irrigation conditions. Cotton fiber quality was not impacted by reducing seasonal irrigation amount. The findings from this study suggest that reducing cotton irrigation water applications by 25% of the full capacity appears to be an effective approach to increase the longevity of groundwater resources while minimizing negative effects on cotton yield and quality in west-central Oklahoma. This innovative irrigation management practice can help producers in water-scarce areas to reduce water usage without sacrificing cotton yield and quality.

Technical Abstract: Water scarcity threatens the sustainability of irrigated cotton production in many regions around the world. Consequently, there is a critical need to identify and test strategies that optimize water use for cotton production. This four-year study evaluated the effects of three irrigation treatments of full irrigation (FI), reduced irrigation (RI) at 75% of FI, and no irrigation (NI) on cotton yield, fiber quality, and irrigation water use efficiency (IWUE) at a field that relies on groundwater for irrigation in west-central Oklahoma. The reduction in lint and seed yields were both 5% under RI and 64 and 65% under NI, respectively, compared to the FI treatment. However, no significant differences (p = 0.900 at 5% significance level) in fiber quality were observed among the irrigation treatments. In addition, reducing irrigation application improved IWUE of lint and seed by 9 and 8%, respectively. Based on these findings, reducing groundwater extraction by 25% seems to be an effective strategy to achieve water conservation while limiting negative impacts on yield quantity and quality for cotton production in west-central Oklahoma.