Influence of Irrigation Pattern on Effectiveness of Furrow Irrigation of Cotton

Cotton is one of the major crops in the Mid-South growing region of the U.S. and producers there often farm numerous fields spread across a large area. Although sufficient groundwater is available for surface irrigation in many areas, the supply and cost of labor is always a concern. Producers commonly employ patterns such as every-other-furrow irrigation to allow them to irrigate fields in one set and thereby avoid the time and labor required to change sets. In many years there is sufficient rainfall that no obvious deleterious effect is observed from the non-irrigated furrows, however producers are concerned that yield could be reduced. A study was conducted at the University of Missouri Fisher Delta Research Center near Portageville during the 2014 through 2016 growing seasons to investigate the impact of different furrow irrigation patterns on cotton yield and canopy properties. Although yield loss due to waterlogging is a constant concern in the region, in 2014, with four irrigations followed by >= 25 mm of rain within the subsequent three days, all irrigated plots yielded significantly more seed cotton than the rainfed treatment. Canopy temperature, plant height, and normalized difference vegetation index were all effective in differentiating between the rainfed and irrigated treatments including differences among some of the irrigation pattern treatments.