permaculture

["Lawrence F. London, Jr." <lflj@bellsouth.net>]

Update: Humanure, trench composting with biomass and weeds, Hugelkulture, 
Revision II

Here's another revised description of this system.

Its a subject of interest to me: how to alternatively, safely,
efficiently and naturally process humanure.

A lot of people use 5 gal. plastic bucket with sawdust (or compost).
Another solution is to, in warm weather, create a trench running with a
slight downhill grade, about 10-16" deep (not critical). Fill it with
cut weeds. Use it, "flush" afterward with buckets of water to dilute and
disperse the solids into the mass of weeds. Use a different spot along
the trench each day. Eventually weeds will grow into the trench and
convert the existing nutrients into plant food. As the level of plant
material drops add new layers of more cut weeds (dried weeds, green or
compost OK).
In winter use the same system but make the trench wider and deeper. Pile
biomass into the trench to 12" above existing grade (it will settle out
so keep replenishing the pile). Use it and "flush" as described above.
Use only the upper half of the length of the trench always. Leave the
lower half to process the humanure and convert it to compost in
combination with the biomass added to the trench.
During heavy rain the trench will flush itself by overflowing onto
adjoining grade and then downhill to fertilize plantings safely.
The extra amount of biomass used in winter will insulate the trench
from the cold allowing the composting process to continue, a little less
in winter but nevertheless adequately. You could always build a little
tunnel type greenhouse to cover and further insulate the trench; lift up
one side of the plastic for access to the trench to use the system. This
might be a sort of modified Hugelkulture composting system.

The humanure trench composting system should have the following
approximate dimensions:
20-40 feet long, 16" to 24" wide and 12" to 18" deep

This should be constructed on a slight grade, with the grade and not
across; finished, clean effluent should exit the lower end during heavy
rainfall.

- The top 25% of the trench should contain compost and cut weeds and not
be used
- The middle 25% is the portion to be used daily; flush with buckets of
water or preferably with water from a garden hose; allow weeds growing
near the trench to grow into the entire length of the trench, especially
the zone used daily
- The lower 50% of the trench is not used and contains compost, cut
weeds and living plant material, annuals or possibly perennials or even
aquatic (for poorly drained soils in which the trench is constructed);
tall annuals work really well, establish a weed seed bank in and around
the trench for a robust, healthy plant community growing around and in
the trench; annuals and rhizomateous plants like Johnson grass, Bermuda
grass, plantain, fescue, ryegrass, daisies, goldenrod, ragweed and many
other "mystery weeds" work really well for this purpose

The upper 25% of the trench, containing bioactive compost, generates a
robust and healthy community of beneficial microorganisms some of which
get flushed into the next 25% of the trench, the active area, helping
the composting and bioremediation to occur efficiently. The lower 50% of
the trench is the finishing area where the process of bioremediation is
completed producing clean effluent to flow out of the trench and
downhill to fertilize plantings or flow into a catchment pond growing
aquatic weeds like duckweed, cattails, papyrus and water lillies.

You do not need to excavate the trench ever, output from overflow downhill 
during rainstorms equals input.
Use the system, reduce all solids to liquid with water (hose or bucket); effluent soaks into a large mass of compost and 
cut weeds as it diffused throughout the active zone and flows into the lower finishing zone for the final stages of 
decomposition. This is all aerobic and completely odor free; nothing is visible except the compost with new layers of 
fresh cut weeds on top. I think there may be some benefit from adding the fresh weeds as they provide, under the right 
conditions, fermented plant extracts. The upper zone, the other 25% of the length of the trench, provides a continual 
source of beneficial microorganisms from the bioactive compost in the trench - you can run water through this area and 
into the active zone periodically to refresh the active zone so that colonies of anaerobic (at trench bottom where there 
are longer periods of high moisture levels) and aerobic microorganisms stay in balance and have adequate populations to 
carry out their work continuously. The trench is designed and constructed so that anaerobic and aerobic microbes can 
coexist and survive in balance without one type dominating the system (obviously is extremely dry conditions the 
anaerobic microbes will recede while during very wet conditions, because of the design and layout of the trench (well 
drained and plenty of compost to absorb liquid) the aerobic microbes will survive in adequate number to continue their 
work and regenerate after the system dries out. It is very important to maintain the aerobic nature of this system. The 
trench design makes this easier to achieve. The system works much better if it can be located in full sunlight and on a 
South-facing gradual slope in cold climates, North for hot climates, to take advantage of lowered temperatures to 
conserve moisture and enable the composting process to work continuously and efficiently. Tall weeds with a lot of 
foliage help shade the lower 50% of the trench and contribute to this also. In Winter they will not be there and are not 
needed as more sunlight and heat will be required to keep the system functional. A small tunnel greenhouse using row 
covers and hoops can be used for this purpose as needed.