Forty years of increasing cotton’s water productivity and why the trend will continue

Authors: BARNES, ED - Cotton, Inc; Campbell, Benjamin - Todd; VELLIDIS, GEORGE - University Of Georgia; PORTER, WESLEY - University Of Georgia; PAYERO, JOSE - Clemson University; LEIB, BRIAN - University Of Tennessee; Sui, Ruixiu; Fisher, Daniel; Anapalli, Saseendran; Colaizzi, Paul; BORDOVSKY, JAMES - Texas A&M University; PORTER, DANA - Texas A&M University; ALE, SRINIVASULU - Texas A&M University; Mahan, James; TAGHVAEIAN, SALEH - Oklahoma State University; Thorp, Kelly

Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/10/2020
Publication Date: 8/16/2020
Citation: Barnes, E.M., Campbell, B.T., Vellidis, G., Porter, W., Payero, J., Leib, B., Sui, R., Fisher, D.K., Anapalli, S.S., Colaizzi, P.D., Bordovsky, J., Porter, D., Ale, S., Mahan, J.R., Taghvaeian, S., Thorp, K.R. 2020. Forty years of increasing cotton’s water productivity and why the trend will continue. Applied Engineering in Agriculture. 36(4):457-478. https://doi.org/10.13031/aea.13911.
DOI: https://doi.org/10.13031/aea.13911

Interpretive Summary: Cotton is a crop that is widely grown in the USA. A large fraction of cotton is grown with irrigation. This paper describes the improvements that have occurred over the past 40 years. The results demonstrate that cotton producers now apply 50% less irrigation water than 40 years ago. Over the same period, the yield produced has increased by more than 50%. These improvements are a result of improved irrigation methods and cotton varieties that yield more with less water. The paper also indicates that as cotton producers continue to adopt new irrigation tools additional reductions in water use are probable. These results are important in that water use in cotton production is often subject to criticism that is often not factual.

Technical Abstract: Over the last 40 years the amount of irrigation water used by cotton in the United States has decreased while yields have increased. Factors contributing to decreased irrigation water use include migration of cotton out of the far western U.S. to the east where more water requirements are met by rainfall, improved irrigation delivery systems (e.g., laser leveling in the west, use of low pressure (low energy) center pivot sprinkler irrigation systems and microirrigation drip irrigation (primarily subsurface drip irrigation) in the southwest, increased use of sprinkler irrigation and precise design of furrow irrigation systems in the mid-south, and the use of variable rate irrigation systems in the southeast), and improved irrigation scheduling tools. Evapotranspiration-based irrigation schedulers are widely available for cotton and are gaining adoption by producers as is scheduling based on soil moisture sensors. Despite successful research using thermal sensors to detect crop water stress, on farm use of this technology is still very limited but may improve as new sensor systems are developed. The ability for average U.S. yields to increase when acres in the most productive part of the country were decreasing can be attributed to improved varieties, better agronomic management and improved irrigation scheduling. The U.S. cotton industry has set sustainability goals that include a continued increase in water use efficiency (WUE) that will require cotton producers to continue their adoption of advanced decision support systems for irrigation management. Increased use of sensors for irrigation scheduling, advances in crop simulation models and continued increase in genetic yield potential will help meet the WUE goal.