Also, a big problem landfills face are the consequences of lack of energy (sunlight and oxygen) in a landfill. Enzymes and microbes are the living organisms that break down waste, and without oxygen, it is an extremely long and hard process to break down or biodegrade that waste (Earth Talk online magazine). Just as seeds need sunlight and oxygen to bloom into a plant, waste needs that same enegry to decompose. Which is why there are waste products that have been sitting in landfills for thousands of years. Also, the process used to create certain things may slow the process down too, making it almost impossible to biodegrade. They form into something that is unrecongnizable, and with the low amount of soil in landfills, they may likely sit there forever. If only we could get everyone to sort their trash, they may be able to make a process that is more effective. Meaning putting things together that are easily broken down such as food, and things that take longer, such as plastic together in seperate landfills that have different approaches. Some landfills are starting to find ways to add oxygen, water and sunlight to help speed up the process but this is pricey and not likely to catch on ( Earth Talk online magazine).
There is a higher chance that if you were to bury your garbage in your backyard, that something might grow out of it, but since landfills are so compacted, it would just sit there for years as previously mentioned. Just like the process of photosynthesis, even garbage needs energy from sunlight and bacteria from the soil to grow into something else or to biodegrade. Photosynthesis is the process by which plants, some bacteria, and some protistans use the energy from sunlight to produce sugar, which cellular respiration converts into ATP, the "fuel" used by all living things. The conversion of unusable sunlight energy into usable chemical energy, is associated with the actions of the green pigment chlorophyll. Most of the time, the photosynthetic process uses water and releases the oxygen that we absolutely must have to stay alive (www.sinauer.com). Although biodegrading waste is not exactly the same process as plant growth, it still uses some of the same concepts and needs some of the same energy to change into a different form.
Larry West, Do Biodegradable Items Really Break Down in Landfills?http://environment.about.com/od/recycling/a/biodegradable.htm
Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com),