The methods used to successfully
compost these materials would differ immensely. The ingredients added to create an ideal windrow for
pine sawdust for instance would be
totally different than for grape skins
and stems. Also the microbes responsible for the breakdown of the
pine sawdust would consist of a
totally different group of microorganisms compared to grape skins
and stems microbes. By selecting
the right microbes which can breakdown, difficult materials can be
composted. Secondly by applying
lime for instance, materials which
might have brought down the pH
to unacceptable levels can be composted. Therefore it is all about
knowing the material you have
available and understanding where
adjustments need to be made to
ensure no problems occur.
You need biodiversity in your compost and this is an essential
“component” in quality compost.
Higher diversity of nutrients and
microbes guarantee compost with
more nutritional value to the plants/
microbes.
What is biodiversity?
Biodiversity is the variety of life
(www.nwf.org). The biodiversity in
compost originates from the organic material, the microbes and also
the inorganic elements which are
added.
Questions which are asked a lot:
Can I compost woodchips and
manure? Yes you can.
Would it make compost? Yes it
would.
Is it the best quality compost that
will ensure sustainable farming?
Probably not! This would be a good
start however by investing more
and adding a variety of green materials, lime, and good quality microbes, better compost will be applied and would be more beneficial.
Another topic in Reduce, Reuse,
Recycle and Repurpose is energy!
Biogas production from waste
products can be an integral part of
any producer’s waste strategy. The
amount of energy in the form of
methane production in different
materials can be seen in graph 1.
With green energy becoming more
mainstream biodigester systems are
becoming cheaper and much more
cost effective. In South Africa with
its electricity crisis it makes sense to
see where energy can be saved but
also where else it can be generated.
Once all the potential energy has
been removed from a “waste”
product the effluent can then be
incorporated in composting to capture the available nutrients and
make it plant available.
By composting the effluent from
the biodigester the nutrients will be
built into the humus complex of the
compost, less leaching and loss of
nutrients will occur. Another very
important conversion will take place
with the composting. The biodigester is dominated by anaerobic microbes responsible for the methane
production and by doing the composting aerobic microbes is added
to the organic material and then
added into the soil when the compost is used, building the microbe
biodiversity in the soil.
There is no easy method for sustainable farming, it is a holistic approach where if something is removed, it needs to be replaced and
by recycling organic material in the
form of good quality compost soil
health can be improved and maintained.
Graph 1 An illustration of the amount of methane production possibilities of different substrates
(http://www.optimaconcept.biz/)