Interaction of irrigation and soil effects on cotton yield

Authors: Vories, Earl; Sudduth, Kenneth - Ken; Drummond, Scott

Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 4/24/2019
Publication Date: 5/28/2019
Citation: Vories, E.D., Sudduth, K.A., Drummond, S.T. 2019. Interaction of irrigation and soil effects on cotton yield. In: Proceedings 5th Global Workshop on Proximal Soil Sensing, May 28-31, 2019, Columbia, Missouri. p. 141-146.

Interpretive Summary: Irrigated agriculture accounts for approximately 80% 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, at the University of Missouri Fisher Delta Research Center Marsh Farm at Portageville in 2016 and 2017 with the objective to better understand the impact of variable soil texture on the irrigation response of cotton. Clay content in the top soil layer varied greatly and yield values were averaged to create a data set containing clay content and associated yield. While the differences among water management treatments were not significant, a strong effect of clay content on cotton yield was observed in both seasons. The study is continuing and these findings, based in a large part on proximal soil sensing, provide useful information to better meet the needs of agricultural producers and improve irrigation efficiency in the US and worldwide.

Technical Abstract: Irrigated agriculture accounts for approximately 80% of the consumptive water use in the US and irrigation has increased in more humid areas of the nation. Soil textural variability within many irrigated fields diminishes the effectiveness of conventional irrigation management and irrigation scheduling methods that assume uniform soil conditions may produce less than satisfactory results on highly variable soils. Furthermore, benefits of variable-rate application of other agricultural inputs can be partially masked by applying inappropriate amounts of water. A field study was conducted at the University of Missouri Fisher Delta Research Center Marsh Farm at Portageville in 2016 and 2017 with the objective to better understand the impact of variable soil texture on the irrigation response of cotton. Treatments included two irrigation management systems and rainfed production. Clay content in the top 0.1 m soil layer, estimated from apparent electrical conductivity (ECa), ranged from 2% to 38%, with more than 40% of the points containing less than 10% clay and fewer than 20% of the points containing more than 20% clay. Yield values measured near an ECa observation were averaged to create a data set containing clay content and associated yield. While the differences among the water management treatments were not significant, a strong effect of clay content on cotton yield was observed in both seasons. While a larger clay content data set and additional years of data will be required to fully determine the impact of soil variability under varying water management schemes, these findings, based in a large part on proximal soil sensing, provide useful information for proper management of variable rate irrigation systems.