Field Experiments were initiated at the Macon Ridge Research Station to assess the effects of various organic wastes on the growth and yield of dryland cotton (Gossypium hirsutum L.). The soil used for these experiments (Gigger-Gilbert complex) contains a shallow hard pan (16 to 21" deep) and is characteristic of the Macon Ridge region. Greenhouse and laboratory studies showed that the compacted, acidic hardpan and underlying subsoil contained high amounts of Al and Mn and will not support cotton development. Field experiments were performed to assess the ability of organic amendments to enhance dryland cotton production on this droughty soil. Four of the most abundant organic wastes in the Macon Ridge area (papermill sludge, papermill fly ash, municipal sewage sludge, composted sewage sludge and selected combinations of these materials) were applied alone or as mixtures as vertical mulches or as broadcast treatments. Responses to these wastes applied as vertical mulches (6" trenches cut to a depth of 21") were compared to those of similar rates applied by broadcast and incorporation. These experiments showed that broadcast applied sewage sludge and sewage sludge plus fly ash significantly increased yields over conventional production practices. In contrast, papermill sludge or a combination of papermill sludge and fly ash significantly reduced yields. Overall, broadcast applications were as effective as vertical mulching. Yield responses were due to combinations of factors. For sewage sludge alone and with fly ash, sustained nutrient supplying ability, net mineralization of nutrients, pH buffering properties, and increased aeration and water holding capacity may have contributed to the increased yields. In the case of papermill sludge, with and without fly ash, decreased yields may be attributed to an net immobilization of nutrients.