As concerns about the viability of the Ogallala aquifer continue, researchers believe they have found a window of opportunity in the growth cycle of cotton to reduce watering without hurting yield in the end.
A recently published Texas A&M AgriLife Research study investigated the best strategies to improve irrigation water-use efficiency while maintaining high yields. Cotton is sensitive to water stress at different growth stages, needing water at specific times to produce a high-yielding crop. You can download a full copy of the study here.
Cotton-boll size and count are greatly affected by the amount and timing of irrigation as well as rainfall and air temperature. Additionally, water districts in the area have imposed restrictions on groundwater pumping to help conserve the aquifer.
Researchers focused on irrigation strategies based on cotton’s five growth stages, with certain stages irrigated more and others less. They used a growth-simulation model that allows testing and analysis of different irrigation scenarios.
The peak bloom growth stage in cotton was found to be the most sensitive stage to water stress, and imposing water deficit during this stage resulted in the lowest seed cotton yield, says Texas A&M University geospatial hydrologist Srinivasulu Ale. But elimination of irrigation during the early and late-season growth stages had little effect on seed cotton yield and irrigation water-use efficiency.
“We also determined that reducing early-season irrigation potentially increased cotton root growth,” says Texas A&M AgriLife Extension ag engineer James Bordovsky. “This helps plants have a stronger resilience to water shortages in later growth stages and increased seed cotton yield.” Cotton Inc. and the Ogallala Aquifer Program funded this study.
There isn’t much specific information about tillage practices in the study. It will be interesting to see if this study’s conclusions prove out when tested in production fields where plants are submitted to countless factors that affect yield. If these researchers are right, though, imagine the payback cotton growers in west Texas could get by adopting no-till practices that boost soil organic matter and stockpile more soil moisture. And with that, let’s close out November with a positive message: Here’s wishing you and your family a very happy and restful Thanksgiving holiday!