Proceedings of the 2023 Mississippi Water Resources Conference

Year: 2023 Authors: Smyly A., Gholson D., Bond J., Bowman H., Bryant C.

Rice (Oryza sativa L.) is one of the most water demanding crops in the Southern United States due to rice typically being grown using a continuous flood production system. Mississippi River Valley alluvial aquifer (MRVAA) serves as a major irrigation water delivery source for rice farmers in the Mississippi Delta. Irrigation water is extensively withdrawn from the MRVAA, and the aquifer is beginning to deplete. Determining an efficient rice irrigation approach is vital to prolong the usage of the aquifer for agricultural needs. Research in Mississippi has shown furrow-irrigated rice (FIR) to produce rice with less water, but there is limited information on proper irrigation and fertilization strategies in FIR. This study was conducted to determine an irrigation management plan in FIR by evaluating rice response to different irrigation frequencies. Research was conducted at the Delta Research and Extension Center in Stoneville, MS on Sharkey clay soil in 2021 and 2022. Four irrigation frequencies (irrigating every day, every 3, 5, and 7 days) replicated three times were arranged using a randomized complete block design. WaterMark® Soil Moisture Sensors®, Pani-Pipes®, Precision King AgSense Sensors®, and flowmeters were used to collect soil moisture, water depth levels, and water usage data from each plot before and after every irrigation occurrence. Rice grain yield was determined for each treatment plot and zones within each plot. On average, irrigation plots in 2021 resulted in greater yields for plots irrigated every day, no difference in yields for plots irrigated every 3 or 5 days, and lower yields for plots irrigated every 7 days. However, 2022 yield data indicated no difference in yield across irrigated frequencies. In 2021, no difference was found in the combined average yield for all treatments between top, middle, and bottom zones. In 2022, top zone average yields were significantly greater from bottom zone average yields, but no difference was seen when compared to middle zone average yields. This research study will be conducted again in 2023.