With increasing production costs in the southeastern US, cropping systems that improve agronomic and economic sustainability are critical. A sod-based system utilizing a two year rotation of establishing and grazing bahiagrass (Paspalum notatum Flueggé) followed by a year of peanut (Arachis hypogaea L.) and a year of cotton (Gossypium hirsutum L.) was established in Marianna, FL. The effect of grazing in this system on root dimensions (length, diameter, and surface area) of cotton was monitored using a mini-rhizotron technique. There were differences in several root parameters between grazed and non-grazed plots (256 m²) including: cotton root length (1260 mm grazed vs. 844 mm non-grazed), surface area (1727 mm² grazed vs. 1105 mm² non-grazed), and diameter (3.09 mm grazed vs. 2.51 mm non-grazed). The roots in the 15 to 30-cm-depth profile had greater length and surface area in the grazed plots with the greatest root surface areas in the deepest soil profile (75-90 cm). Grazed plots also exceeded nongrazed plots in seed cotton yield (3967 kg/ha vs. 3335 kg/ha) and lint (1672 kg/ha vs. 1444 kg/ha). Increases in root architecture associated with cattle grazing in this system may enable cotton to better withstand adverse environmental conditions such as drought stress, thereby improving long-term sustainability.