This page describes of some of my ongoing and completed experiments with vermicomposting. Contact me with any suggested projects, questions about these projects, or to discuss the results.
Using Vermicomposting to Manage Pet Waste-- "Doggie Dumpster" (Also see my blog entries on this topic.)
What to do with pet waste? It is common courtesy to pick up after your pet, but once you bag the poo what do you do? What is the most ecologically responsible and sanitary way to dispose of it?
The sad fact is that (while it is one of the simplest and neatest methods) by using a plastic bag to pick up, store, and dispose of dog waste you are effectively preserving what is otherwise bio-degradable. Consider that the amount of dog waste alone produced in the U.S. every year is enough to fill a football field up to 800 feet deep, and you can see the scale of the problem.
One way to deal with the biodegradable issue of your petís waste is to switch to biodegradable bags or walk with or use a pooper scooper rather than, say, a recycled grocery bag. Most types of biodegradable bags degrade in a month, and these bio-bags are comparably priced to other plastic dog baggies. Pooper scoopers are free after the initial investment. No matter how you pick it up, you still have the problem with where to dispose of it. One green option is to put it in your own pet waste disposal system that will break down the waste and avoid sending it to the landfill.
The concept is to create a mini-septic tank for your pet waste. You bring the biodegradable bag or scooper home and place it in there to break down. The cool thing is that you can use septic tank bacteria/enzymes or red worms (or both!) to break down the poo.
Make your own pet waste composter (Also see my supplies page.)
Take an old garbage can (with a lid) and drill a dozen holes in the side. Cut out the bottom. Dig a hole in the ground, deep enough for the can. Toss some rocks or gravel in the bottom of the hole for drainage and position the can so it's a slightly higher than the ground. Then deposit the waste and sprinkle in some septic starter and water or red wigglers and vermicompost. Put the lid on and start using it. (City Farmer has a great photo gallery Step-By-Step photo guide.)
It occurred to me that you could also scale this down. Here's what I did... Thanks to Heather for hosting this project (I don't have a dog). I went to the store and bought a Rubbermaid 2 gallon trash can with rolltop lid (easy access). Cut off the bottom and dug a hole that was the same diameter as the can, but about 8" deeper. I put in the can and added about 2# of red worms and worm compost. The photo below shows what it looks like in the ground. I think the roll-top will be really convenient.
June 2008 UPDATE: My friend Heather started hers in August 2007. She added dog poo for 8 months (she has a black lab as well as a visiting lab occasionally). After 8 months it was nearly full to the level of the surrounding soil. I was visiting and moved the poo pit. I was surprised to find a lot of nicely composted material at the bottom... top had fresh feces, but that's what I expected.
Here's what I did to move to a new location:
1. First I dug a new hole. It was the same diameter as the can, but about 8" deeper (same as before).
2. After removing the lid I dug out the sides of the trash can (some material stuck to the sides, but most stayed in the hole, falling out of the open bottom).
3. I flipped the cylinder upside down to put the newer material back in the old hole upside down. Then I covered the hole with the soil from my new hole.
4. I slid the (now empty) cylinder into my new hold, added about a pound of worms & compost and put the top back on (took me about 10 minutes in all).
I am very pleased with the success of this. If you've tried it, let me know how it works for you. Next time I move Heather's I'll take some photos.
If you're looking for something easier, there are a number of commercial in ground pet waste containers available to purchase from my Amazon store.
Once you build or buy it, here are some recommendations:
1.) Do not put pet waste in your normal compost pile.
2.) Do not use the castings produced from pet poo in your food garden. Pet feces may contain harmful pathogens and should not be handled, especially by pregnant women. The castings should be fine for flower gardens and perennial beds.
3.) Like any worm composting operation, monitor conditions when you make additions (add water if it appears too dry, add bedding if it appears too wet.)
4.) In the winter (when soil temps drop below 40įF), biodegradation will slow down. You can plan for this and size your hole accordingly (volume or depth) depending on the season.
Using Vermicomposting to Sustainably Manage Horse Manure
I learned of this from a web article by Colorado State University Cooperative Extension (Vermicomposting Horse Manure by A.B. Card, J.V. Anderson and J.G. Davis).
Briefly, the concept is to use redworms to turn your horse manure into compost. I thought this would be a great experiment to try at my brother's horse farm Summerwind Farm Sporthorses. The web article presents 2 options; we used option 1 in which aged horse manure is placed into a windrow and seeded with redworms.
We started on September 10, 2006 with about 5# of redworms. As shown in the photo below, this is likley too few worms for the amount of horse manure used, but it is a start. Note that 5# of redwroms will cost approximately $100.
Step 1: Build the windrow and seed with worms
UPDATE April, 2007: Steve reported that he has harvested some beautiful black soil for his garden from the windrow. They also see many wild turkeys picking through the windrows-- could they be eating the worms???
UPDATE August, 2007: Steve reported that the windrows have been a success. He has been able to manage his manure better with less runoff.
More experiments coming soon... If you have an idea of something you'd like me to try, contact me.