A compost turner is a machine used for aerating and mixing compost materials in order to accelerate the composting process. It can be used to mix and turn organic waste materials, such as food scraps, leaves, and yard waste, to create a nutrient-rich soil amendment. There are several types of compost turners, including manual turners, tractor-mounted turners, and self-propelled turners. They come in different sizes and configurations to suit different composting needs and scales of operation.