Compost video script (8m 12s)
Composting is how we speed up the process of the soil food web. It’s what makes humans more efficient than nature, because we can create more in a shorter period of time. Faster, more. The two insatiable adjectives that drive human behavior. Why do we plant crops? Why do we build cities? Because we want to go faster, we want moooore.
So the first thing I’ll talk about is the carbon to nitrogen ratio. This is a mathematical calculation of the fastest decomposing compost pile.
Nitrogen is the energy used to consume carbon, the fuel. We want a ratio of 30 parts of carbon to 1 part of nitrogen. For every part of nitrogen consumed by a compost pile, it consumes 30 parts of carbon. A ratio closest to 30:1 will break down a compost pile evenly and quickly. Too much nitrogen and it will get too hot and lose volume. Too much carbon, and it only slowly decompose.
There is a list of C:N ratios for common composting materials: wood chips are around 400:1, newspaper is 250:1, and then substances like urine are around 7:1. When you add all of your composting materials together, you want the average ratio to be 30:1. This will provide enough food and energy to consume itself, not too much.
I found in practice though, if you mix even parts of brown and green materials, the pile will most likely break down in good time.
In practice, the first thing to do to make compost… is to walk around and see what materials you have. Look for weeds, patches of land you want to clear, trees that need pruning, look at your neighbors curb. Just gather organic material and make piles near where you want to make compost.
Don’t have any material on-site? Drive around town with a pickup truck. You’ll be amazed what you find when you have your composting goggles on.
Making a compost pile
There are generally two types of compost piles: long-term and short-term piles. A short-term pile will break down in about a month, whereas long-term piles can take 6-12 months or more to fully decompose into compost. It depends on the thickness of the branches you use. When making a short-term pile, the main thing to keep in mind is to use organic matter smaller than the thickness of your finger. Long-term piles are good for making paths in an overgrown forest. Add sticks to the bottom of a long-term compost pile to create air flow.
Then for the shape, you want to make the pile between 1-1.5 meters cubed. This makes it easier to flip later on. If you have more material than allows in this space, make a longer pile while maintaining the original 1-1.5m size.
When building a compost pile, you want to add layers 10-20cm thick of each type of material. Mix 50% brown, 40% green and 10% high-nitrogen materials. Each layer should consist of one type of material. Next, cover the pile with a tarp – this keeps it dry in wet climates and wet in dry climates. After four days, flip the pile using a pitchfork or your hands. Turn the pile every other day for 3-4 weeks. This method is also called the 18-day Berkeley method of composting… the pile could decompose completely in just 18 days.
Observing the pile
After a few days, there should be heat coming from the middle of the pile. Temperatures will reach between 50-60º C, enough heat to where if you put your hand in the pile, you would pull it away and say. This is called the “ow” test. If you pull back, it means the pile going through the thermophilic phase of decomposition. In this temperature range, the weed seeds and harmful microorganisms die. Also a white fungus called actina will appear in the middle of the pile. If you feel heat coming from the pile or see this white fungus, you’re in good shape.
To determine whether you have enough moisture in the pile, grab a handful of compost, and squeeze it. A few drops… no more, no less, should run down your arm. This is 50-60% moisture content. This is what you’re going for.
There’s a good section from the documentary Symphony of the Soil that demonstrates how useful organic compost is… “(from film)We make about 200-300 yards of our own compost every year entirely from materials here on the farm. We have friends and neighbors who are irrigating plants 3-4 hours of drip per day, we’re doing about 1 hour of drip per week.
Here what we see is soil from the Rodale Farming systems trial. We have 300mL of water that is going to be introduced to 1000g of soil. Here is the simulated rainfall. When we have the mulch and the organic system and compost there is more water that is being absorbed into the soil. Now you see how clear the water is here. As we improve the soil, we get much less run off. When we look at the bottom of our containers, we see that no water runs through the conventional soil. As we introduce these organic methods, you’ll see we are getting not only less water loss on the surface. But we’re getting water charge on the subsurface which is feeding our aquifers and our surface streams.”
What is compost tea?
Compost tea is aerated compost liquid fertilizer. Also called actively aerated compost tea (AACT). Liquid fertilizers are soluble, meaning it is easier for plants to absorb the minerals… It makes it easy on them. You want it to be easy for plants to grow.
How to make compost tea?
- You can make compost tea in any sized container. Several videos online use 20L bucket or 200L barrels.
- Fill container with 20-30% compost or compost materials. You can also add things like molasses, maple syrup, sugar cane juice or fruit juice for increased bacteria content [Bacteria like sugar]. Add kelp, humic acid or rock dust to increased fungus content [fungi like carbohydrates]
- Fill the rest of the bucket with water.
- Then aerate the mixture using an aquarium pump or a larger air compressor. Dr Elaine Ingram advises to point the aeration device directly on the compost, this physically breaks apart the minerals from the compost. Aerate for at least 2 hours, 24 hours is more ideal. Apply immediately to the garden while the oxygen content is high.
You can also get creative with your tea maker design and how you aerate the mixture.
What is mulch?
Mulch is organic material spread on top of compost to enrich, insulate and retain moisture in the soil. This increases nutrient uptake by the plant and creates an ideal habitat for microorganisms. Nature actually mulches itself – Trees grow a thick layer of their own fallen detritus (det-tree-tus).
Types of mulch materials include: Dried leaves, straw, cardboard, sawdust, wood chips, used clothes, mattresses, newspaper and branches. You can use green material in your mulch, just be aware you may be making a small compost pile and the pile could generate heat and damage the seeds.
Building biomass is important when establishing a forest or garden on fallow land. Fast growing pioneer species like lukina, glycidia, moringa, acacia or any other legume grow relatively quickly.
Everywhere you put compost, put mulch. You never want to expose compost to the sun. When compost dries out, all that microbial content you’ve been working so hard to create, goes away. Add mulch to retain that moisture in the soil.
So quick recap:
- Compost is how we speed up the soil food web. It’s fairly easy to make.
- It demonstrates how and why humans are awesome creatures (because we can speed up the process of nature).
- And mulch keeps compost moist and shaded while it builds biomass in the soil.
Okay, This concludes the chapter on compost and mulching. Thank you for your time.