With high input and high value of cotton, cotton growers may be interested in precision agriculture for cotton production. The successful application of this technology is mainly dependent on the identification of key limiting factors and the adjustment of controllable factors. More data are needed to support precision agriculture on cotton. The objectives of this study were 1) to evaluate spatial variability of cotton yield and soil parameters within irrigated fields and 2) to identify relationships between the soil and plant parameters. This research was conducted on two irrigated cotton fields in West Texas in 1998. Growing season precipitation was less than 40% of average. Cotton yield had a high variability within the fields we studied. Yield tended to be negatively related to clay content and positively related to sand content across soil types within a field during this season. Soil parameters and other factors influencing variability within a soil type are being further examined. Soil parameters that influence yield may or may not be amenable to variable rate application. If lint yield is related to nutrient level, it is possible to variably apply nutrients. If yield is influenced by moisture availability due to soil texture and organic matter content at a point in a field, it still may be possible to vary fertilizer or other inputs based on moisture availability.