Green Amherst

Composting at Amherst College

Finished Compost

Starting in the Fall of 2009, Amherst College implemented post-consumer food waste composting in Valentine Dining Services.  The results of this program have been significant.

The program is diverting approximately 8 tons of food waste each month to a local farmer.  

Just this fall, by having this organic material converted to compost instead of sending it to the landfill, we have reduced greenhouse gas emissions by the equivalent of taking 2 cars off the road for an entire year.    

What is Compost

Composting is the naturally occurring biological decomposition or organic matter by a variety of micro-critters (bacteria, fungi, etc.) into a stabilized material that we call compost.

veggiesCompost in Soils

When added to soil by farmers, gardeners, and landscapers, compost adds to soil structure and tilth and reduces soil compaction.  

Compost in soil acts a bit like a sponge and improves the soil’s ability to hold water and nutrients and release them slowly as plants need them.

In addition to holding nutrient, compost is rich in nutrients like nitrogen, magnesium, and phosphorous that plants need.  And it has those nutrients in a form that plants can use.  Not only do plants need those nutrients, but they need them in an organic form for plants to be able to absorb the nutrients.  Compost provides nutrients in that organic form that plants need.

Compost and Climate Change

Composting food waste avoids the methane generated in landfills.  If food waste is thrown away in a landfill, it decomposes anaerobically, generating methane, a greenhouse gas 25 times more powerful than CO2.

Composting helps to store greenhouse gasses out of the atmosphere.  Photosynthesis removes carbon dioxide from the atmosphere and stores it in plant tissue. Composting plant remnants after they die or are harvested helps return that carbon to the soil and store it there.

Composting also adds valuable nutrients to the soil.  If those nutrients are not replenished by natural means such as compost, they have to be added by synthetically manufactured fertilizers.  Composting food waste returns essential Nitrogen and Phosphorous to farms and landscapes in a form that plants can use.  To make synthetic chemical fertilizers to do the same thing, it takes a lot of energy and emits a significant amount of greenhouse gas.  

According to recent estimates by the U.S. EPA, 13% of all U.S. greenhouse gas emissions are from the provision of food and that almost 35% of all the energy used in U.S. agriculture is used just to manufacture fertilizers and pesticides.

According to a recent article by Dr. Sally Brown, it takes 4 units of CO2 for each unit of synthetic nitrogen fertilizer and 1.75 units of CO2 for each unit of synthetic phosphorous fertilizer (BioCycle, October 2009).

Learn More


Cornell Composting

Martin's Farm Recycling

The New York City Compost Project

US Composting Council

Please Note: Amherst College does not officially endorse any of these products or organizations. They are listed here only as a convenience to assist students and the Amherst College community to find recycling information or find recycled-content products.

The sites listed above are the sole responsibility of the vendors or organizations who maintain them. Amherst College is not responsible for any content on the sites listed above.