A traditional agronomic practice used by crop consultants for soil testing is to take a representative sample from the field of interest. New Mexico State University recommends characterizing fields that are no more than 40-acres in size. From the 40-acre field at least ten sub-samples should be taken and composited to characterize the field. Grid sampling to assist in determining field variability and suitability for variable rate fertilizer technology has provided an assessment of the composite recommendation. The standard deviation of field parameters can be used to determine what is a “representative” sample from a given field. Soil pH, electrical conductivity, organic matter, and DTPA extractable zinc required the fewest number of subsamples (<5) to estimate the field mean within a 95% confidence interval. Soil nitrate, bicarbonate extractable phosphorus, and ammonium acetate extractable potassium varied tremendously with the number of sub-samples varying from 74 for nitrate to over 550 for potassium on one field. This suggests that partitioning a field into zones can have a profound effect on management for a cotton grower. However, some parameters such as potassium read in excess of the required level of production and would not need to be managed with variable rate technology. Other agronomic issues such as irrigation water uniformity, incidence of Phymatotrichum onmivorum, and other pests can have more of a profound effect on cotton production than fertility issues.