The Science Behind Composting

The Science Behind Composting

That banana peel in the waste bin will eventually, naturally decompose, as will all organic waste, thanks to helpful microorganisms in the environment that feed on the decaying detritus.

Composting is a process that works to speed up the natural decay of organic material by providing the ideal conditions for detritus-eating organisms to thrive, according to the United States Department of Agriculture (USDA). The end-product of this concentrated decomposition process is nutrient-rich soil that can help crops, garden plants and trees to grow.

The composting process

Microorganisms are vital to the composting process and are found everywhere in the environment, said Matthew Worsham, the sustainability and energy coordinator at the University of Dayton in Ohio.

The key to effective composting is to create an ideal environment for the microorganisms to thrive, Worsham told Live Science — warm temperatures, nutrients, moisture and plenty of oxygen.

According to Cornell University, there are three main stages in the composting cycle in which different types of microorganisms thrive.

The first stage is typically only a couple of days long during which mesophilic microorganisms, or microorganisms that thrive in temperatures of about 68 to 113 degrees Fahrenheit (20 to 45 degrees Celsius), begin physically breaking down the biodegradable compounds. Heat is a natural byproduct of this initial process and temperatures quickly rise to over 104 degrees F (40 degrees C).

Mesophilic microorganisms are replaced by thermophilic microorganisms (microorganisms that thrive in the increased temperatures) during the second stage, which can last from a few days to several months. The thermophilic microbes work to break down the organic materials into finer pieces. The higher temperatures are more conducive to breaking down proteins, fats and complex carbohydrates.