Other chickens walk around the bale browsing around the edges of the bale, and eating the alfalfa flakes that get scratched off onto the ground by the upper chickens. Alfalfa is a very nutritious food crop. Alfalfa sends it's roots deep into the soil.
Soil or Waste Stacks. A soil or waste stack (normally just called a stack) is a drainage pipe that passes through at least one story(floor to ceiling) as a drain pipe, this also includes any horizontal offsets. Every soil or waste stack will terminate in a stack vent that leads to outside air or a vent header.
Compost & Green Waste. Green waste (also known as yard waste) makes up a significant portion of the solid waste that is disposed of by residents. Diverting this material from the solid waste stream helps extend the useable space of the landfill and keep methane-producing materials out of the landfill.