Applying Composted Cotton Gin Trash to a Vertisol in Southeastern Queensland, Australia

Many Australian cotton farmers are interested in using organic waste products such as composted cotton gin trash as soil amendments because of perceived benefits to soil health and the environment. However, detailed information on the relative benefits and costs involved is not readily available to cotton growers who farm on clayey Vertisols. The objective of this study was to quantify soil changes in a farmer-established trial to evaluate the potential benefits of applying composted cotton gin trash and/or lime to a Vertisol. Selected soil properties were measured in an experiment located on a commercial cotton farm near Goondiwindi in southern Queensland, Australia. Cotton gin trash compost improved potassium availability and soil microbial biomass in soil, whereas lime improved only the latter.