Studying Cotton Yield Response to Irrigation Regimes and Spatial Soil Variation in a Humid Region

Cotton is one of the major crops in west Tennessee which is also vital for US economy since it is an essential export-oriented product. Cotton supplemental irrigation is growing fast at west TN. The temporal pattern of rainfall changes from year to year when unexpected drought periods likely occur within each growing season. The spatial soil variation is also significant and is expected to happen under a single irrigation system. These variations make irrigation management a complicated dynamic problem hence crucial to study. A two year experiment was conducted at 2013 and 2014 in a 70 ha field located along Mississippi river where two center pivot systems were available. The main objective was to study cotton yield response to irrigation regimes under drastic soil spatial variation. Irrigation was varied across the field of study by programming center pivots and renozzling some spans to apply more/less water than the prime irrigation decision by farmer. The soil maps were generated by sampling and running a veris EC machine. Soil water status was monitored during cropping seasons and weather data was obtained from a within-field weather station. The yield maps will be accurately analyzed and compared against irrigation and soil maps to investigate the influence of soil-water variation on cotton lint yield.