Even though some cotton varieties have natural drought tolerance built in, weather patterns of erratic rainfall and predictions of increased competition for water resources in the future are of concern to the entire cotton-growing community. Last year, Cotton Incorporated managed more than 40 research projects that were explicitly focused on better ways to capture rainfall, manage irrigation water and improve crop wateruse efficiency.
This three-pronged research strategy is employed to help cotton continue its positive trend in increasing productivity without increasing water use.
A major issue for producers right now is rainfall capture. Rainfall patterns often do not match water needs of the crop, or rainfall occurs at such high rates it is not possible for the water to penetrate the soil surface. Historically, one approach farmers have used to cope with rainfall leaving the field is the use of farm ponds to collect rainfall runoff.
These ponds will continue to be an important tool in the future, and research is being conducted to determine if the utility of the ponds can be increased in certain hydrologic settings by allowing the pond to leak into the soil profile to recharge shallow water tables. This allows increased water storage without sacrificing water to evaporation or land allocated to increase pond size.
Precision Application And Scheduling
Even in humid areas, irrigation can increase productivity when rainfall is delayed during the season. Precise management of irrigation water is an important tool to optimize productivity of the land and to ensure that no other inputs go to waste. New technologies have provided several tools producers now use to develop sustainable crop water management strategies.
One such tool is widely distributed cellular networks that affordably transmit near real-time data from sensor networks monitoring water status in the field. This allows easy access to the water status of the plants in the field so water is only applied when needed.
The precision of water delivery is also increasing with new application technologies. The use of Low Energy Pressure Application systems is now common throughout the southwestern United States, and it is estimated that nearly 300,000 acres of cotton are now grown under drip irrigation, thanks in part to Cotton Incorporated funded research.
Improved Plant Water Use Efficiency
The final key strategy is to look for all mechanisms possible to make the cotton plant even more drought resistant and water efficient. One way this can be accomplished is through traditional breeding techniques by crossing varieties that demonstrate superior performance under drought conditions. In the future, there is also hope that progress already made in unlocking the cotton genome will provide new insights into the genes that contribute to drought tolerance. Several projects attempt to improve cotton’s root growth and stand establishment under drought, using seed processing, conventional breeding and biotechnology.
While not solely focused on water efficiency, Cotton Incorporated funds more than 70 research projects each year to increase yield and quality – increases to date that come without increased water use.
For more information on cotton and water, visit http://cottontoday.cottoninc.com/agriculture/water/.
The Cotton Board, which administers Cotton Incorporated’s Research and Promotion Program, contributed information for this story.