Observing Soil Respiration Materials Local soil sample (approximately 2 cups) Disposable plastic water bottle Plastic tubing Small jar or clear container with an opening only slightly wider than the plastic tubing Small cup or 100 mL beaker Graduated cylinder Duct tape (or other waterproof tape) 5 g sugar 105 mL water Bromothymol blue and color change chart Plasticine clay (optional) Object to rest the small jar/container on (optional) Procedure Cut a plastic water bottle about a quarter of the way down. [Read More]