Equipment and techniques were developed to study the moisture absorption and desorption rates for cotton trash components at temperatures ranging from 5 to 80 C (41-176 F). The moisture data were transformed and found to fit a theoretical, falling rate curve. Nonlinear regression analysis was used to fit the value of the coefficients in the theoretical equation to the experimental data. Results indicate that both temperature and air type (dry or humid) significantly affect the coefficient containing the diffusivity parameter in the nonlinear equations. As expected, moisture transfer rates increased as temperature increased from 5 to 80 C and the drying rate was higher than the humidification rate for each cotton trash component at the same temperature. Leaves had the highest moisture transfer rates followed by burs and then sticks.