|Sudduth, Kenneth - Ken|
|Evett, Steven - Steve|
|ANDRADE, ALEJANDRO - Orise Fellow|
Submitted to: Precision Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/24/2020
Publication Date: 8/3/2020
Citation: Vories, E.D., O'Shaughnessy, S.A., Sudduth, K.A., Evett, S.R., Andrade, A., Drummond, S.T. 2020. Comparison of precision and conventional irrigation management of cotton and impact of soil texture. Precision Agriculture. 22(2):413-431. https://doi.org/10.1007/s11119-020-09741-3.
Interpretive Summary: Irrigated agriculture accounts for the majority of the consumptive water use in the US and soil textural variability within many irrigated fields diminishes the effectiveness of conventional irrigation management. Benefits of variable-rate application of other agricultural inputs can be partially masked by applying inappropriate amounts of water. A field study was conducted by ARS scientists from Portageville and Columbia, Missouri, and Bushland, Texas, at the University of Missouri Fisher Delta Research Center Marsh Farm at Portageville in 2016 and 2017. The objective of the research was to compare rainfed cotton and cotton irrigated based on the USDA-ARS Irrigation Scheduling Supervisory Control And Data Acquisition (ISSCADA) system and a water balance method; and to better understand the impact of variable soil texture on the irrigation response of cotton. Although the trend was for the rainfed treatment to have the lowest yield in both years, the yield differences were not significant when sand content was not considered and a strong effect of sand content on cotton yield was observed in both seasons. The study is continuing and these findings will be used by cotton producers to improve irrigation efficiency in the US and worldwide.
Technical Abstract: Soil textural variability diminishes the effectiveness of conventional irrigation management. Variable rate irrigation (VRI) can address soil variability; however, users need guidance to prepare prescriptions for optimal water application. A study was conducted at Portageville, MO, USA, in 2016 and 2017 with the objective to compare yield and irrigation water use efficiency among three water-management treatments for cotton: rainfed, irrigated based on the USDA-ARS Irrigation Scheduling Supervisory Control And Data Acquisition (ISSCADA) system, and irrigated based on a water balance method. Sand content in the top 533 mm soil layer was estimated from apparent electrical conductivity (ECa). Yield values measured near an ECa observation were averaged to create a data set containing sand content and associated yield. Although the trend was for the rainfed treatment to have the lowest yield in both years, the yield differences among all treatments were not significant when sand content was not considered. A strong effect of sand content on cotton yield was observed in both seasons, although the slopes differed among the water management treatments in 2016. The ISSCADA system tended to have a higher irrigation water use efficiency in both seasons, but the difference was not significant in 2016 when total irrigation applications were low. The study is continuing at Portageville and other locations and the ISSCADA system is constantly being improved to better meet the needs of agricultural producers.