Organic Compostfrom THE
by Mort Mather
Simply put, compost is the best soil amendment there
is. It adds nutrients, improves soil texture, improves
the soilís ability to hold moisture and at the same
time improves the soilís ability to dry when it is
too wet. Compost widens the acidity/alkalinity (pH)
range within which plants will thrive. Properly done
it will kill pathogens and weed seeds. It will turn
smelly materials like fish scraps and manure into
Composting is taking place in nature all the time.
It is how the rich soils of our Great Plains were
built. It takes place in our lawns if we leave the
grass clippings and on forest floors. It is part of
the cycle of life turning dead things into nutrients
to feed the living. It is the process whereby organic
materials are turned into humus.
You may have noticed a pile of leaves that seems to
stay pretty much the same for years. Composting is
going on here but only at the bottom of the pile where
the leaves come in contact with the soil. Composting
needs a combination of materials. The leaf pile also
sheds water when it rains so that you may find the
pile to be pretty dry. Composting needs to be moist
but not soggy.
Most organic gardeners separate their kitchen
scraps from other waste and add it to the compost
pile. It cuts down on the waste stream and puts the
valuable nutrients back in the soil where they belong.
This practice causes some others to say, "How do
you keep it from smelling?Ē The smell associated
with garbage is due to anaerobic bacteria. Sometimes
we will let our compost bucket hang around too long
and we will get a little smell. That is due to the
materials on the bottom ending up under too much
compacted material so they get no air.
Meat will also get smelly. We put meat scraps in a
plastic bag in the freezer. Sometimes I compost these
as well. Sometimes they go to the dump. In the winter
we donít have a lot of vegetative material to add to
the pile which means that birds and animals can pick
through it. We donít want to attract meat-eating
animals. Sometimes in the summer Iím too busy to
make sure meat scraps are well covered by other
materials, so to the dump. Meat scraps also take
longer to be decomposed, usually surviving several
So, compost needs organic materials (more than one
kind), water and air. There are a lot of ways to do
it. Sheet composting is the easiest. You just throw
whatever you have on the garden and turn it in. I have
done this many times with manure mixed with sawdust,
shavings or straw and sometimes straight manure. I
spread it in the spring and turned it into the soil.
Certified organic growers have to compost manure, by
the way, or spread it 120 days before harvest.
Sheet composting is fine as long as there is a good
supply of nitrogen. Manure is the usual supplier of
nitrogen. If you spread just sawdust which is a
material high in carbon, The soil microorganisms will
be overworked for a while breaking down the material
and crops may suffer from a lack of fertility. Some
say the organic material has robed the soil nitrogen.
It is more accurate to say ďborrowedĒ as once the
soil is back in balance it will benefit from the
additional organic material that, for a time, caused
an imbalance. Thus we have another consideration in
making compost, the carbon nitrogen ration C:N.
The C:N ratio of sawdust is 400 to 1 while for
rotted manure it is 20 to 1 and young sweet clover is
12 to 1. All of these materials once composted are
pretty close to 50 to 1. Iím not going to go any
further into C:N here other than to say you will have
a better compost pile if your mix of materials
includes some high nitrogen materials and some
Thatís all you really need to know. If you shred
the materials, they will compost much faster. No
surprise as you are exposing much more surface for the
microorganisms to work on. The better you mix them,
the faster they will work. If you put them in a bin
with vertical sides through which air can flow, the
pile will compost faster and be neater. If you are
going to leave the pile through a rainy season, it is
best to cover it so nutrients wonít leach away.
Here is an example. I have a bin I made nearly 30
years ago out of wire mesh and 1 by 3 redwood. It is 4
sides about 3.5 feet to the side and the same height.
I screw the sides together with 2 screws to each
corner. I can remove the screws and take the sides
away to relocate the bin next to the pile and turn the
pile back into the bin or start a new pile.
I generally start a pile with weeds or garden
refuse, fairly coarse stuff. Then some leaves or grass
clippings being mindful that if I make too thick a
layer of these they may pack down and stop the flow or
air. Then some more weeds, then an inch of soil, then
some leaves or grass, some garbage collected from
somewhere, some more topsoil, some fish scraps from
the fish market, more weeds, etc. I may have been
collecting materials for weeks or months. Iíve
always got my eye out for some organic matter that I
can pick up free and store easily. I mentioned fish
scraps. Great fertilizer. Remember the Native
Americans used to put a fish in each hill of corn? It
can get pretty smelly and attract insects and animals
if not incorporated into the pile. I collect these
goodies when I have other materials handy and am
otherwise ready to build the pile.
Dampen the materials as you build the pile. If
there is a good C:N ration, the pile will get quite
warm in a few days. When it cools turn it trying to
get the outside closer to the inside of the pile. If
you shredded the materials you will have finished
compost in a couple of weeks, so they tell me. Iím
pretty casual about the whole thing so I usually start
a pile in the fall and finish it in the spring. Spread
it and start another which usually just get
incorporated into the fall pile.
Remember, this process is going to take place with
or without you. To the extent you control it you will
capture more nutrients for your garden and let less
good stuff end up in a landfill or incinerated. Can
there be a much more foolish waste of energy than to
cart organic materials that are mostly water many
miles to an incinerator to burn them?
© 2001, Mort Mather
Mort is a husband and father. He authored a book,
Gardening For Independence and was named
Environmentalist of the Year by Down East Magazine in 1987. He is
a consultant for organizations. You
can eat his organic produce at his son's southern
His address is 802 Bald Hill
Road, Wells, ME 04090.
Mort retains all rights to his columns. Anyone
interested in using them can get the rights at a very reasonable rate.