Notes from Windward: #71

Routing Around the Ducks

getting ready to upgrade Duckponics

Walt:

     We call our intermediate 1,200 gallon aquaponics system "Duckponics" because we use ducks instead of fish to generate the waste that feeds the plants. We started out with ducks and fish, but the tank is small enough that the fish couldn't hide from the ducks and quickly became duck food.

     Last year, it became evident that it was time to take what we'd learned about the system and do some renovations and improvements. While we haven't arrived at a consensus on how we're going to improve the duck's shelter, it is clear that the duckponics area needs to be enlarged and better protected.

     Natural systems are complex. In all probability, nature is a web of connections more complex than humans are capable of understanding in total. And so, we proceed according to one of the principles Heinlein laid out in The Moon is a Harsh Mistress,

     "When faced with a problem you do not understand, do any part of it you do understand, then look at it again."

     For more quotes from Harsh Mistress, Click Here.

taking out a small oak
  


     Since the southern boundary of the current duckponics area is formed by a commonly used access road, the necessary first step involved rerouting that access road. We looked at the possible routes from a number of angles in an effort to minimize the number of trees that needed to be removed, and to take into account the flow of ground water through that area.

cutting off the root ball
  


     One reason for doing this work now while the ground is fully wet is that even large trees can be pushed over by the track hoe. If that was tried in the summer, the trunk would snap off before the roots gave way. This way, the whole tree comes out of the ground.

     The next step is to take a chainsaw and cut off the root ball. Then the trunk is cut up into lengths appropriate for our sawmill where it will be turned into 1" thick boards suitable for making furniture or moulding. We hate to take down a living tree, but when necessary, the next best thing is to make sure that it's well used.

digging out an oak cluster stump
  


     A key way that oaks are different from evergreens is that when you cut down an evergreen, the roots die and eventually rot away. When you cut down an oak, the root system doesn't die. Instead it sends up a series of shoots that eventually will grow into more oak trees. It's this ability to regrow from a living root mass that enables a copse forest to product three tons of dry wood in the same time that pine or fir trees would need to produce two tons.

[Note: different types of wood have the same heating value per pound. A heavy wood such as oak takes longer to grow than a light wood such as pine, so it's important to think in terms of wood mass instead of just volume. A cord of dry oak has a lot more heat value than a cord of dry pine because it weighs a lot more.]

     While that's usually a good thing, in a situation like this, the oak root ball has to be dug up and removed before attempting to lay down a permanent road bed. The bulldozer George is using has the ability to rotate its blade so that it can use a corner to dig away at the root ball. Given the plastic nature of our soil right now, it didn't take very long before the root ball popped out of the ground.

forming the new road bed
  


     With the trees, roots and all, moved out of the way, the next step involved creating a smooth road that curved around the summer rabbit area. When reasonable, we like to curve roads like this so that they look more natural to the mind's eye.

backing in with a load of crushed shale
  


     With the new road bed in place, the next step was to bring up crushed shale to put down to form a stable surface. Trying to drive vehicles over the raw dirt would kick up dust in the dry season, and prove unworkable when the ground is wet and slick.

     Getting the shale in place without getting the dump truck stuck is a bit tricky. In the picture you can see that George has stopped at the edge of the existing road to dump the first load. Once it was on the ground, John used the dozer to spread it out on the new cut and walk it in.

starting to unload
  


     With the second load, George was able to back in over the spread out shale, thereby pressing it into the ground firmly. With that first load acting as a bridge over the soggy part, George was able develop some momentum and back the truck uphill a ways before it lost traction. Starting from there, gravity pulled the truck downhill, leaving a trail of crushed shale behind.

rolling down hill
spreading out the rock
  


     From that point on, it was a simple matter for the dozer to even out the shale. A third dump truck load ensured that the new road bed was thick enough to handle traffic for years to come.

spreading it out and walking it in
  


     
Notes From Windward - Index - Vol. 71