A Microcosm System for Looking at Decomposition of Horseshit

This work is being done to provide data towards the creation of the BioShaft, a project under development with designer Domenico D'Alessandro.  The BioShaft is a soils-based treatment system for the decomposition of human fecal waste.  The decomposition products will fertilize a green wall and other urban vegetated systems.  Our initial work at DePaul uses horse manure as a surrogate for human waste and is designed to examine to rate of decomposition and the efficacy of leachates as fertilizer.

For more on the BioShaft design see here

We set up the first of our experimental systems today:

Our horse manure.  Each student used approx 30 g of manure.

The manure is place into a microcosm (we are using a Nalgene filtration unit). 

A piece of manure is surrounded by one of three treatments: garden soil, mulch or perlite.  To these will be added a microbial treatment to accelerate microbial decomposition.

Each unit has approx 800 ml of substrate that surrounds the unit.

18 microcosms were prepared today!

Decomposing with Cotton Strips...the beginner's guide!

Simple cotton strips can be used as a surrogate for other organic matter (leaves etc.) in the study of decomposition.  Decomposition is measured by the loss of tensile strength in the buried strip!

Positioning Your Strips

             It is important that the strips are randomly placed in your garden. To ensure this take a small object (stick etc.) and toss it "blind" over your shoulder into your plot!  This will be your "central point. (see diagram)

    

           The strips will be positioned around this central point.  They should be arranged as a triangle with each point about the distance of your foot (assuming it is an average foot!) with the central point occupying the center of the triangle. (see diagram)

Inserting the strips into the soil.  NB For this you will need a garden spade

       The strips are placed into the soil vertically.  When they are properly placed the top (marked with a label) will be uppermost and will stick out of the surface. (See photos).  BEFORE placing them in the soil a slot for each strip should be opened up with the spade.  Push spade into the soil to the approximately 9 inches.  Move the spade back and forward a little to ensure that the strip will go in effortlessly.

      Remove the space and lay the strip along the length of the space.  The label (plastic tape) will be towards the top of the spade (closest to the handle).  Wrap the very end of the strip (where it is marked with a blue line) around the tip of the spade.

      Reinsert the spade with the strip into the soil.

   Carefully withdraw the spade leaving the strip into the ground.

     Tamp around the edges of the ground close to the strip to ensure there is good contact between the soil and the strip.

     You are done with this strip!  Repeat steps 3-7 for the remains strips (completing the triangle).

Last Step: The Control Strips

        This is a vital last step.  Pick a point close by to the other strip and repeat steps 3-7 with each of the 2 control strips but this time as soon as you are done remove the control strips.

           

          When removing the strip ensure that they come out with minimal effort.  If necessary loosen the soil with a trowel, taking care not to damage the strips.

     Store the controls in a place where they remain dry until returning all strips at the end of the experiment.  

Removing the Strips

       The strips should remain in place for 28 days (4 weeks).

      To remove the strips loosen the soil around each strip with a trowel (or comparable garden tool) making sure that you do not damage the strip. 

      When the soil is loose gently ease the strip out of the ground.

       Place all strips into the self-addressed envelope that we have provided (along with the control strips) and returned them immediately.

DePaul Environmental Science Student, Alexandra Patrickus, proudly holding a Cotton Strip.

In The Kingdom of Decay: How a Motley Team of Subterranean Dwellers Ransacks the Dead and Liberates Nutrients for the Living

The recently dead rot much like money accumulates in banks (until recently, at least), only, of course, in reverse.  A sage great-great-ancestor who had, for instance, set aside a few shillings for a distant descendant would, through the plausible alchemy of compound interest, have made that great-great-offspring a wealthy person indeed.  In contrast, after death a body-heft of matter accumulated over the course of a lifetime is hustled away, rapidly at first, but leaving increasingly minute scraps of the carcass to linger on nature’s banquet table.  It is as if Zeno had not shot an arrow but instead had ghoulishly slobbered down upon the departed, progressively diminishing the cadavers but never quite finishing his noisome meal.  The soils of the world contain in tiny form, scraps of formerly living things going back many thousands of years.  Perhaps these are the ghosts we sense when we are alone in the woods.

Before you rake away the final leaves of the autumn season, hold one up to the early winter light.  Those patches where you see sky rather than leaf are the parts that had been consumed live, nibbled away by insects or occasionally browsed by mammals.  But you may have to pick up several leaves to see any consumption at all!  The eating of live plant material is rarer than one might suspect.  It is almost as if most creatures, unlike us of course, have the decency to wait for other beings to die before they consume them.  Ecologists have wondered why this is the case, asking in one formulation of the problem “why is the world green?”  At the peak of the summer season the world is mysteriously like a large bowl of uneaten salad.  The world it turns out is green for many reasons but a compelling one is that plants generally defend themselves quite resourcefully.  The thorn upon the rose provides more than a pretty metaphor – this shrub knows exactly what to do with its aggressive pricks.  And if one can neither run nor hide nor protrude a thorn, you might manufacture chemical weapons.  Crush a cherry laurel leaf in your hand, wait a moment or so, and then inhale that aroma like toasted almond.  It’s hydrogen cyanide, of course.  “Don’t fuck with me” is one of the shrubbery’s less lovely messages.


Read on at 3quarksdaily

Japanese Maple (Acer palmatum)

 

The Japanese Maple is dropping its leaves

Now that the elm is spent and in its winter-nude.

Those maples leaves that linger on the branches

Are like hands outspread and chilled raw

That waited to scatter scarlet decorations

To pave the way for a sullen monarch.

Decomposing Thought

Living things are born and die.  And living things rely for their living on the dying of other living things.  This is a central ecological thought – the decomposing thought.  A thought compelling enough to sustain an enduring research program: investigations of decomposition of dead organic matter (DOM) remain at the core of ecosystem ecology. These studies have promoted an understanding of the importance of the upper 5cm of soil – Earth’s tumultuous rind – where the roiling community of decomposers consume and transmute the apparent uselessness of dead flesh into the currency of ecosystems.  Input: DOM.  Process: decomposition by microbes regulated by the tiny champing of soil fauna – mites, springtails, and their divers kind. Output: energy for decomposers and the mineralization of the organic into nutrients available to the living.