Dr. Elaine Ingham - Compost

Dr. Elaine Ingham discusses the Science of Compost

YouTube Video

Composting at Home: Two Easy Methods founders show two easy how-to composting methods and discuss environmental benefits of keeping food waste out of landfills. Learn more at

Human Urine for Compost

Urine adds Nitrogen and Water to your compost. Easy. Free (actually it SAVES money by avoiding wasteful flushing of your toilet). Clean (human urine is sterile, unless you have a UTI (urinary tract infection, during which you should probably flush it down your toilet). Think of the millions of gallons of water that cities could save if citizens avoided the wasteful flushing. Meanwhile, it helps microoranisms make compost into great soil. My motto: "Urine may look YELLOW, but it's environmentally GREEN!"

18 days Berkley Compost

Also called "hot compost" because of the temperature of the composting process (55-65 C) which is crucial in getting it right.

The main benefits of this method of composting include:
  • it lasts only 18 days
  • it kills pathogens and seeds (for that the temperature must be 65 C for 72 hours straight)
  • but not the beneficial microorganisms (if the temperature is not higher than 70 degrees)
  • it comes out very fine and well composted - perfect for the nursery
The downsides:
  • mostly the work it takes to be turning it and checking the temperature regularly
  • And that you have to have the right materials which are not always available

Very important factor is that the ingredients together have a ratio of C:N - 30:1 approximately.

Therefore, the ingredients used usually include:
  • Manure (a big source of nitrogen and activates the composting process
  • Green scraps from the garden and/or kitchen (quite high in nitrogen)
  • "brown" material (straw, sawdust, woodchips, cardboard - anything that has a lot of carbon)

The process

    1. Making the pile

The minimum size of it is 1m width and 1,5m hight - this is so that we achieve enough mass to reach the desired temperature.

All materials should be shredded.

Place your pile in a place that is sheltered from direct sun and rain.

To make the pile put your materials in layers (about 10cm each) one after another and water after each set of layers - your pile must be soaking wet.
Keep in mind that you have to have about 3 times as much carbon as nitrogen!
You can put inside of the pile so called "activator" that will make the whole process faster. those include the food scraps, dead animals, urine and some particular herbs - nettle, omfrey, dandelion.

It is good to cover your pile with something that will protect it from rain, loosing water through evaporation and loosing heat.

Cover it and wait 4 days.

    2. Turning the compost

Usually after 4 days - but basically when you reach the desired temperature - you turn the pile inside out. 

To know if the temperature is right, the easiest way is to use a termometer, but you can also check it with your hand - if inside of the pile is so hot that it burns, you probably got it right.

You usually turn every two days, but if the temperature is too high, you will have to do it more often.

To turn it inside out, follow this diagram:

3. Adjusting the temperature and water content
If the temperature is too low - there is not enough nitrogen:
  • Add some activator, best - blood and bones fertilizer or fresh manure
  • add some water (if the pile isn't too wet already)

If the temperature is too high - too much nitrogen:
  • Add something with a lot of carbon - sawdust or shredded cardboard
  • turn it
Water content should be such, so that when you squeeze compost in your hand you get about one drop of water coming out.

Toxins in Compost

Composting is a classic example of working with nature. When designing compost piles, we are mimicking the natural process of decomposition. We design compost to increase in speed of decomposition, life and diversity beyond the natural process. 

Compost is a vital part of nutrient cycling for sustainable food production. In this video Geoff discusses small amounts of toxins being included in compost processes.
How much do we need to worry about whether our compost ingredients have been in contact with pesticides? What about kitchen scraps from conventional growers?


There is a good article in Wikipedia about compost.  This is an extract:

With the proper mixture of water, oxygen, carbon, and nitrogen, micro-organisms are allowed to break down organic matter to produce compost.

 The composting process is dependant on micro-organisms to break down organic matter into compost. There are many types of microorganisms found in active compost of which the most common are:

  • Actinomycetes- Necessary for breaking down paper products such as newspaper, bark, etc.

  • FungiMolds and yeast help break down materials that bacteria cannot, especially lignin in woody material.

  • Protozoa- Help consume bacteria, fungi and micro organic particulates.

  • Rotifers- Rotifers help control populations of bacteria and small protozoans.

In addition, earthworms not only ingest partly-composted material, but also continually re-create aeration and drainage tunnels as they move through the compost.

A lack of a healthy micro-organism community is the main reason why composting processes are slow in landfills with environmental factors such as lack of oxygen, nutrients or water being the cause of the depleted biological community.