Compost: What is it? Part 1
By John Ferguson
Spring 1997

We hear a lot about compost these days, from its miraculous benefits, to stories of how much it stinks. 

What is compost?  Let’s start by looking at a few definitions.

 

From Webster’s Dictionary we get:  Compost-  1)a mixture that consists largely of decayed organic matter and is used for fertilizing and conditioning land  2)mixture, compound  3)to convert (as plant debris) to compost.

From The Rodale Book of Composting we get:  “Composting is, in broadest terms, the biological reduction of organic waste to humus.”

 

From The Practical Handbook of Compost Engineering we get: “Composting is the biological decomposition and stabilization of organic substrates, under conditions that allow development of thermophylic temperatures as a result of biologically produced heat, to produce a final product that is stable, free of pathogens and plant seeds, and can beneficially be applied to land.”

 

From the laws of the State of Texas as published in The Texas Register, Title 30 - Environmental Quality, Chapter 332 - Composting, we get the following definitions:

 

Compost - the stabilized product of the decomposition process that is used or distributed for use as a soil amendment, artificial top soil, growing medium amendment, or other similar uses.

 

Composting or functionally aerobic composting - the controlled, biological decomposition of organic materials through microbial activity which occurs in the presence of free oxygen.

 

Cured compost- A highly stabilized product which results from exposing mature compost to a prolonged period of humification and mineralization.

 

As you can see, there is a very wide opinion or understanding as to what compost is.  Terms like biological reduction, humus, stabilization, thermophylic temperatures, functionally aerobic and free oxygen, mature compost, humification and mineralization all complicate one’s understanding of compost.

 

Our knowledge of compost and composting has grown from the art of backyard composting into a full-blown research field with several universities now offering Ph.D. programs in compost technology.

 

Basically, compost is like any other product we buy and use.  It can be many different things depending on how it is made, what it is made from, and how it is to be used.  It can vary from poor quality and worthless, to extremely high quality, and valuable.  To illustrate, compost prices in the United States range from free ($0.00) to over $2.00 per pound (i.e. $2,000/cubic yard).

 

The use of different types of compost also varies.  Erosion control, potting media, fertilizer, fungicide, root stimulator, earthworm food, moisture control, bioremediation of explosives and toxic wastes, disturbed land reclamation, wetland re-creation, air filtration, water filtration, food preservative, microbial stimulant, are all uses of compost.