Soil - where it all starts and ends: Compost Part One

Here's what it's all about: (Air + Water + Carbon + Nitrogen) + Time = Compost

To start with just let me admit that I'm almost totally compulsive/obsessive about compost. I'll explain why I say "almost" later. If there is a key to Organic Gardening, it is compost. It is the number one source of nutriants and structure for the soil. It is the way we replenish the soil. It is what turns dirt into soil.

Enough... I'm not going to go into a big long speach about the why to make & use compost, etc. If anyone really wants to read it, just ask. For now I'll just talk (well, type) about what it is and how to make it. Note: Keep in mind, this is basic, beginners level, you might say Compost 101.

There are five things basic ingredients that go into making compost: Air, Water, Carbon, Nitrogen, and Time. And it is important to remember that thesew are all variables.

Air. Like most living things, the microbes, bacteria, fungi, worms, and insects that make up the compost ecosystem, need air. Compost scientists (yes, there are compost scientists) say compost piles need porosity. I say what the hell is "porosity"? It turns out that is means the ability for air to move into the pile. I like to think of porosity in terms of fluffiness. A fluffy pile has plenty of spaces for air to move about. A flat, matted pile does not. Even fluffy piles compress during the composting process due to settling and as the material breaks down. Occasionally turning your pile refluffs the material, moves new material into the center, and helps improve air flow into the pile.

Water. Compost microbes, bacteria, fungi, worms, and insects also need the right amount of water. Too much moisture reduces airflow, causes temperatures to fall, and can make the pile smell; too little water slows decomposition and prevents the pile from heating. Conventional wisdom says that compost should feel like a wrung-out sponge.

Carbon ingredients. The microbes that break down organic matter use carbon as an energy source. Ingredients with a high percentage of carbon are usually dry and brown or yellow in color. The most common high-carbon ingredients are leaves, straw, and corn stalks. Sometimes people call these ingredients browns.

Nitrogen ingredients. Microbes need nitrogen for the proteins that build their tiny bodies. Ingredients high in nitrogen are generally green, moist plant matter, such as leaves, or an animal by-product, such as manure. These ingredients are called greens, but in reality they can be green, brown, and all colors in between.

Time. If mix together some straw, corn stalks, and some manure, get it moist, then stir in some air, you will NOT have compost. It takes time for the microbes, bacteria, fungi, worms, and insects to "do their thing", so to speak. The amount of time can vary from about 2 months to about 2 years, depending on a few things. Probably the most important is the C/N ratio. In order for a compost pile to decompose efficiently, you need to create the right ratio of carbon (C) to nitrogen (N) (C/N). Piles with too much nitrogen tend to smell, because the excess nitrogen converts into an ammonia gas. Piles with too much carbon break down slowly because there's not enough carbon for the microbe population to expand. An ideal compost pile should have a 30:1 C/N ratio or 30 pounds carbon to 1 pound nitrogen. Grass clippings alone have about a 20:1 C/N ratio. Adding one part grass clippings, to two parts dead leaves, will give you the right mix.
Another thing that effects the time is how well you monitor the moisture. If you allow the pile to dry out the microbes stop working because they die. If you get it too wet, the air spaces will be gone and the microbes stop working because they die. To be accurate, the composting work will slow way down because most microbes, etc. die. Except under very extreme conditions there will always be some air and moisture.
Another thing that effects the time is how small the stuff in the pile is. A pile of finely chopped grass, straw, leaves, whatever will compost more quickly.... much more quickly.
Another thing that effects the time is how often you turn or stir the pile. When you turn the pile you are getting air in and the fluffing action gives small (really tiny) air spaces. You are also helping (speeding up) bringing the microbes, etc., and the to-be-composted stuff together. On the other hand, you can turn the pile too often. What that will do is cause the pile to dry and reduce heat build up.

And speaking of heat. There are two main ways to make compost: cold compost (minimum effort) and hot compost (maximum effort).

Cold: Nearly every gardener I have talked to has admitted (sometimes sheepishly) that they do this type of composting in their own backyards because it's easy. Here's how to make cold compost: Mix together yard wastes, such as grass clippings, leaves, and weeds, place them in a pile, and wait 6 to 24 months for the microorganisms, earthworms, and insects to break down the material. Add new materials to the top of the pile. You can reduce the waiting period by occasionally turning the pile and monitoring and adjusting the pile's moisture level. The compost will be ready when the original ingredients are unrecognizable. Generally, compost on the bottom of the pile "finishes" first.

Pros: Takes little effort to build and maintain; can be built over time.
Cons: Takes up to two years to produce finished compost; doesn't kill pathogens and weed seeds; undecomposed pieces may need to be screened out.

Hot: Hot, or fast, composting takes more work and the right combination of ingredients, but you can get high-quality compost in under two months. Here's how: Wait until you have enough material to create compost critical mass (27 cubic feet), which is the minimum volume for a pile to hold heat. Then mix one part green matter with two parts brown matter. Bury any vegetative food scraps in the center to avoid attracting animals. Check to make sure the mixture has the ideal moisture level. Continue adding mixed greens and browns and checking the moisture until you've built a pile that is 3 feet x 3 feet x 3 feet, or 5 feet wide at the base and 3 feet wide at the top. The microorganisms will immediately start decomposing, and their bodies will release heat. The pile will insulate the heat, and the temperature of the pile's interior will reach 120 to 150 degrees F. Turn the pile weekly and regulate moisture levels. After about a month, the hot phase will be done, and the pile will finish decomposing at temperatures between 80 degrees F and 110 degrees F. The compost will be ready to use when it no longer heats and all of the original ingredients are unrecognizable.

Pros: Produces high-quality compost within 2 months (and sometimes as soon as a few weeks); can kill weed seeds and pathogens.
Cons: Time-consuming; requires careful management of moisture, air, and C/N ratio.

Next we'll go into what to put in and what to not put in to a compost pile.

Peace,
poor_old_dad

 

Question?

Please don't laugh.. lol.. but I am really new to this. We recently bought a old farm house out in the country and am going to attempt a garden this spring. I live in Canada, so its cold for over half the year. I really want to have a compost pile.. both for gardening and for waste reduction. The snow is what is confounding me.

I bought a little "under the sink" compost bucket. Its contents are rotting comfortably under the kitchen sink. Its almost full though, and am stuck with what to do next.

I don't have enough compostables to move the pile outside, but I have more that what my little container will hold. How can I compost inside this winter without the smell kicking us out of the house? I have a large basement... could I buy a larger container to hold my compostables until spring? Or should I just start the pile out behind my shed now?

thanks!

regan (icedteapriestess)

 

sure you have enough to start a pile outside ITP... use leaves n such to begin it with,, you really do not want your compost composting with in the confines of the house,,,, or atleast i wouldnt think you would,,, perhaps one the lil compost machine things you buy and then in the basement would be an option ,,, but i truly don thtink i would want all my leftover things in my home..

 

dad, have you ever tried the direct composting method at all and if you have how well does it work,,, i have been toying with the idea for a while now and was seriously considering this for one of the gardens sorta as a trial session

 

See, I don't have enough to start a pile outside. Winter has arrived, and with it came almost a foot of snow. Everything I could have used is now quietly rotting by itself under all that snow. Thanks for replying though!

 

why not clear a area, take what you have indoors and start a pile,then continue adding your indoor waste.if you feel what you already have indoors isnt enough go buy a couple bales of straw,wouldnt cost more than 10 bucks and it would give you a really good start to a pile then.
use a tarp to cover it and periodically clean the snow off the top. seems simple enough to me...

beats the hell outta stinking up your basement if you ask me.

just because theres snow on the ground is no reason to not have a compost pile outdoors...

 

thanks. Hadn't really thought about physically clearing a spot. Guess I thought the matter would just sit out there and not do anything because of the cold, which really makes no sence as leaves break down under the snow over the winter. I really know nothing about composting. Total newbie at all of this. Large scale farming I know, but gardening is lost on me. Give me a combine and I am good to go, but ask me how to start a compost heap and I'm useless. lol.

 

I swear i read somewhere that using a lot of grass clippings in a compost pile will create an acidic soil mix, is this true?

Also, i've also heard that adding fertilizer to the mix will help things move along quicker, do you have any suggestions as to the NPK strength needed?

 

To start with, let me say I'm sorry for taking so long to respond. I should have mentioned that I always take a long end of year break from, well, everything. This year even more so. This year, during the holiday season, I became a Grandpa & turned 60 & partied my ass off.

Anyhow, now back to business...

First of all, I will never, never, ever laugh at someone asking a serious question.

Next of all, as has been suggested, go ahead and "start the pile out behind my shed now". It may be too cold & the stuff might just sit there, but so what? In the spring (and I've lived in Canada - spring is great), you will have collected a lot of material to get your pile off to a great start. Of course so much time has passed since your original post you've already done what you're going to do.... what did you do?

Peace,
poor_old_dad

 

Wow, what a couple of great topics you have brought up.

First of all, "direct composting", for those reading this who don't know the term, direct composting means that rather than starting a compost pile, you take the materials you would have put in a pile and instead, spread them out directly in & on the garden, and let them decompose there.

Like everything else in life, there are plusses and negatives. Plusses: are things like it saves time and there is no loss or waste (due to leaching, etc) of compostable materials. Negatives: composting uses nitrogen and if you are direct composting a lot of just carbon materials, the nitrogen already in the ground will be used, & maybe used up, in the decompostion process. So if you're adding carbon, you need to add nitrogen, so there will be some (nitrogen) left for the growing plants to use. This can be done most easily by adding manure or blood meal. But then that brings up another problem, you shouldn't add (much) manure or blood meal or any high nitrogen to where you have growing plants due to the problem of "burning". The solution is to either do the direct composting to an area you are preparing for planting - or - use some very mild nitrogen sources such as green plants in with the direct compost materials.

Dilli, you asked if I ever do this... yes I do. Here's a little of the how, when and why of that. It's a little bit of a jump ahead, it's one of the next topics I was going to go into soon, but I do a lot (A LOT) with mostly legume cover crops/green manure crops....

Definitions:
Cover crop - a crop planted to keep the ground covered during non-productive times of the year. Probably one of the best ways to prevent soil erosion.
Green manure crop - a crop planted to be "turned under" for the purpose of improving the soil. Sometimes, cut & raked up & added to a compost pile.
Legume - any of a large family (Leguminosae syn. Fabaceae) plants, bearing nodules on the roots that contain nitrogen-fixing bacteria, and have the ability basically to take nitrogen from the air and put it in the ground (when I first heard of this I thought it was fuckin' magic). Legumes including important food and forage plants (as peas, beans, clovers and others).

... so turning under green manure crops is direct composting and using legumes solves the nitrogen availability problem. Plus the roots help break up & aerate the soil too.

The other very important thing you mentioned is doing a trial. No one crop, variety, technique or anything else works for everyone. And as hard as it is to believe, even after many thousands of years of gardening/farming, there are still new things coming along. Setting aside an area (or areas) to try new things & different ways is .... well, more important than I can express. It may be THE key to long term sucess!!!

Peace,
poor_old_dad

 

As far as I know, grass clippings will not create an acidic mix. Fresh (green) grass clippings are high in nitrogen, dried (brown) grass clippings are a good source of carbon for a pile. Adding pine straw to a compost pile will make it acidic and can help acid loving plants. But it takes a long, looooong, time to break down. Instead, I use on acid loving plants, I use pine straw as a mulch. That way I have a more balanced, neutral compost and the acid only where it's needed... like on azaleas but not on mint.

As to adding fertilizer into compost. There is a lot of debate about that. I add my own homebrewed fertilized mix to my compost. It is a combination of Kelp meal, alfalfa meal, blood meal, bone meal and rock phosphate. I will give my gaurded secret formula later. The main thing is it is very evenly balanced in terms of NPK, but from the kelp & alfalfa there is also a long list of minerals and natural growth hormones, etc. I only add a little, each time I turn a pile, and my experience, based on my own tests, is that it does help, clearly helps.

Peace,
poor_old_dad