Irrigation management for cotton can become a difficult task due to the way cotton responds to irrigation and weather conditions. There are many irrigation scheduling tools available to producers, but determining which one may be the best fit for their operation can be a daunting task. The main objective of this study was to evaluate various irrigation scheduling strategies for cotton production in the southeastern US. The subobjectives of this study were: to monitor soil moisture and determine optimal irrigation timings for each method, to log the total and distribution of rainfall and irrigation during the season for each irrigation scheduling method, and to determine the effect of irrigation scheduling method on final crop yield and irrigation water use efficiency (IWUE). A nine-treatment irrigation scheduling trial was implemented at the University of Georgia’s Stripling Irrigation Research Park. Cotton was planted on May 7, 2020 and harvested on October 26, 2020. Three Watermark soil water tension sensors integrated into a probe at depths of 6, 10, and 14 inches, were installed in two of the three replications of each treatment. The nine treatments implemented included 20, 45 and 75 kPa soil water tension treatments, USDA-ARS Irrigator Pro for Cotton, Crop Metrics CropX sensor system, Valley Irrigation’s Sensor Scheduling System, UGA SmartIrrigation Cotton App, the UGA Checkbook, and a rainfed treatment. A total of 21 inches of rainfall were received during the cotton production season, indicating a relatively wet season. This is also reflected in the low amount of irrigation which was applied via the UGA Checkbook (only 9.5 inches). After the cotton was harvested, final yield, IWUE and an estimated profit calculation was determined. While there were no significant differences between lint yield except for the rainfed treatment, there were differences in IWUE and profitability. The top three yielding treatments in order were the 45kPa, the 20 kPa and the SI Cotton App, while the CropX, 75 kPa, Checkbook were the lowest yielding treatments. From the perspective of IWUE the 75 kPa treatment was the highest and the Checkbook the lowest. This shows that yield alone should not be the only consideration when considering irrigation scheduling methods and end goal on the farm.

свернуть