This thesis has explored the diffusion of tile drainage in Delaware County, Indiana. The study discussed some of the deterrents that hampered agricultural development in the county. These obstacles included the presence of thick forests, vast areas of swampy lands, poor transportation facilities and the absence of local markets. Methods of overcoming some of these problems were then discussed. These included the clearing of forests to prepare land for cultivation, and the use of open ditches and clay tiles to drain the marshes.In addition, the introduction of new drainage techniques such as the laser beam, plow drain, and plastic tile were also discussed. The rate of adoption of plastic tile was then tested statistically to find out if it followed any pattern of distribution. Data obtained through interviews with selected farmers revealed that such an innovation will tend to approximate a growth or "S"-curve in about 1980. The study concluded that the majority of Delaware County farmers are still using clay or concrete tiles.