Problem: We have too much manure!
Solution: Turn the manure into compost.
Challenges:
We have 3 beautiful horses, Rusty, Bolt and Carmello. They are good boys and produce a lot of manure. In the past, we have piled the manure into compost heaps, hoping that good soil bacteria would create compost for us. When I have used this in my garden, everything-even the weeds have grown very well. This shows me that the composting action is not occurring in the compost heap, but in the ground, after I have put it in the garden.
Most commercially provided compost is from steers, not horses. Steers have a ruminant digestive system with four chambers of stomach, while horses have a single chambered stomach for digestion. Steers have so much acidity in their stomach that seeds are destroyed while horses do not. Horses spread a lot of seeds, which is a challenge when I use their manure in my garden. I get weeds everywhere.
 |
| Ruminant Digestive System of the Steer - Image Courtesy University of Minnesota Extension |
 |
| Non-Ruminant Digestive System of the Horse - Image Courtesy Iowa State University |
Procedure:
In thinking about this issue, I reflected on a lab I did while teaching high school Environmental Science. (I am now a clinical supervisor for secondary science education at Western Governors University, helping to license teacher candidates in science.) When I taught Enviromental Science, we did the Ward's Composting lab activity. It was a fun lab where we used a plastic animal aquarium and took the challenge to recycle waste from around the school. We shredded assignments and swept up wood shavings from the woodshop lab, put in the microbes, attached a hot plate and thermometer and grew our own compost. It took two months, then we grew our own tomato starts in that compost! Great lab.
It taught the fundamentals of working compost.
Fundamentals:
1) For adequate composting, the temperature needs to be between 30 to 70 'Celsius, or 135 to 160 degrees Fahrenheit. (4)
2) Microbes come from the soil; no inoculant is needed.
3) Air needs to get into the pile, so rotation is needed.
4) Moisture needs to be present.
5) When composting is working it smells like "dirt", indicating respiration is occurring.
6) The volume of the pile decreases.
Observations:
1) My manure pile is too cold to produce compost.
2) The volume of my manure pile does not decrease.
3) My pile does not smell like "dirt', it smells kind of alcoholic, like anaerobic respiration is occurring.
Brainstorming Solutions:
1) I need to increase the temperature of the compost pile. I could try burning yard waste and mixing it in.
2) Taking regular readings of the temperature of the manure pile.
3) Design of the manure heap. It is currently 3-sided wood palettes. (5)
Experiment:
I am going to pick one problem that I think is the posing the greatest challenge and attempt to work with it. I think the design using palettes is effective since a lot of websites use it. I think the reason why there are too many weed seeds in my manure is that it is not becoming compost because my pile is not hot enough.
Hypothesis:
If I can create a pile that maintains adequate temperatures, then the manure will become compost through the native microbes in the soil, without inoculant.
Solution:
1) Burn yard waste and mix the hot ashes with the manure to raise its temperature.
2) Take readings of the temperature.
3) In the future - use mirrors and clear carbon panels or plastics to create a greenhouse effect to raise the temperature of the compost pile. I recently saw this idea of how to make an entire greenhouse out of plastic water bottles. Could I use this idea to provide insulation for the compost pile or a lid for it to increase the greenhouse effect to trap heat? (6)
What I have done so far:
Well, I still have to scoop up the manure. Thankfully, my horse Bolt used his brain. I left the paddock chore to go eat lunch and he stood and guarded the wheelbarrow until I came back. My horses are so protective!
I took the dried piled of manure and put it outside in a well-ventilated area. Then I build a fire on top of it using yard debris. When the fire burnt out, it resulted in hot manure being added to the pile, along with ashes. Yes, ashes does change the pH of the soil, it raises it. Considering I live in an area where there is very basic (low pH), adding ashes to raise soil pH is a good idea. (7) At least it's better than "cooking" the compost in my oven. (Really! I read that in a gardening book!)
How do I measure success in this project?
There are a few observations that lead to success:
1) The temperature of the pile will operate at the idea range of conditions.
2) The volume of the pile will be reduced to at least half by the aerobic microbes.
3) When the compost from manure is used, the weed seeds will have been destroyed by the heat and will grow the correct specimen plants.
Future Plans
I will update how the manure turning to compost is going. I need to now think of a good way to check the temperature of my compost pile. Apparently, just using a high school lab thermometer is not likely going to be effective for this large of a scale.
Citations:
1) University of Minnesota Extension: Ruminant Digestion Link. The ruminant digestive system
2) Iowa State University Outreach and Extensions: Horse Digestive System. Digestive Anatomy and Physiology of the Horse | Equine Science
3) Ward's Composting Lab Activity: Ward's® Composting Investigations Lab Activity | Ward's Science
4) The Compost Chronicles: https://thecompostchronicles.com/what-is-the-optimal-composting-temperature
5) Planter's Post- How to build a composter out of palettes: How To Build A Composter Out Of Pallets – No Dig Vegetable Gardening Blog
6) Hub Pages: How to build a plastic bottle greenhouse. How to Build a DIY Greenhouse Using Plastic Bottles - HubPages
7) Unified Garden - Are ashes good for the soil? Are Ashes Good For The Garden Soil? (Explained) – Unified Garden
