Tuesday, September 3, 2013

Composting - A General Overview

Everybody nowadays seems to be big into the idea of composting. I'm frequently asked if I compost and how do I do it. While I believe composting has its place, I don't believe that everything needs to be processed through a traditional compost pile. 

First of all, why compost in the first place? For me it's a source of nutrients for my plants, the worms, the micro-organisms, the soil in general. It's my form of fertilizer. It fits perfectly with the idea of self reliancy, self sufficiency, low input farming. And it also keeps plant waste out of landfills. Compost can improve soil fertility, soil structure, and moisture. Used as a mulch, it keeps down weeds, shades the soil, and provides humidity in the plant zone. I rototill compost into the upper couple inches of the garden soil, which the plants respond very well to. I use compost to create growing beds and fill in container gardens. Composting (hot) also allows a gardener to utilize manures in a safe manner by killing off pathogens. 

When someone starts asking about compost, they invariably are referring to hot compost piles. But there are other ways to compost. Composting is decomposition of organic matter, thus it can be a slow process or a fast process. It can be a cold compost or a hot compost method. Composting can be done in a pile, in plastic trash bags, in bins, in a trench, or in layers like lasagna. Composting can also be done by using the material as a mulch. The idea is to create an environment where organic material will breakdown. That means providing oxygen (air) and moisture, but not so much moisture that it blocks out the oxygen.  

On the farm I compost in a variety of manners. 
1- Mulching. By using grass clippings as mulch, the grass decomposes over a period of a few months. While protecting the soil from the sunlight and preventing the germination of weed seed, it slowly feeds nutrients to the soil and provides food for worms, beneficial insects, and fungi. I've also used finished compost from the piles as a mulch instead of grass clippings and it works quite well. 
2- Trenching. I often have buckets of fruit rinds or slaughter waste that I don't want to leave  exposed because it will draw vermin. The quickest way to incorporate this into the garden is to dig a trench beside a row in the garden, fill it with the waste, then cover it with the dirt. There it will breakdown within a week or two. The worms go crazy over it. 
3- Rotary bin. At the community garden there are 3 of those rotary composting bins. Many people bought them and they turned out to be failures for them. Luckily for the community garden, 3 people donated their failed bins. The garden volunteers have come up with a good use for these bins. Each week one of the bins is emptied of "finished" compost then refilled with chicken pen litter. 1st week, bin #1. 2nd week, bin #2. Etc. The bins are checked and rotated daily. The system works perfectly. It turns chicken pen litter into useable compost in just three weeks. For those three weeks, the material stays very hot, too hot for most pathogens in the manure to survive. The stuff gets too hot to handle with bare hands. 
    Question: why did these rotary bins fail previous gardeners but not the community garden volunteers? It's a case of understanding the needs of the compost. The moisture in a closed bin is often too high, so it needs to be checked and adjusted daily. Sometimes the lid is left cracked open, wider some days, perhaps shut on others. The composting material needs to have a balance of manure to non-manure material, which volunteers do by adding grass clippings as needed, sometimes fresh green clippings (=manure), other times brown dry clippings (=non-manure). The bins needs to be turned daily because in the bins the material settles readily, thus blocking out the oxygen. With daily attention, the composting environment stays in the ideal working range. But the trick is daily attention and tweaking. 
4- Pallet box piles. I make a box by wiring 4 pallets together and lining it with cardboard. I fill it by laying in weeds, clippings, manures, inter layering wood ash, biochar, coral sand, processed bones. I add water as I make the pile and cover it with cardboard to retain moisture while keeping out excess rain. After a couple of weeks I use a Mantis tiller or a three prong hay fork to remove the material and flip it into a neighboring box. If I need compost in the garden, I'll use it right away. If not, it gets stored in the next box until needed. This type pile gets very hot, so it is good for processing manures and dead animals.
5- Container beds. I fill my various container gardens with layers of composting material before topping it off with 3-5 inches of soil. The material fills  up the space, since real dirt is in short supply around here. Plus as it decomposes, it feeds the plants. I just take care not to use woody material or wood chips which are notorious for becoming nitrogen gobblers as they breakdown. 
6- Biotrash pits (aka: hugelkultur). On my main farm I have a number of rather large holes in the ground that I am gradually filling in. Once filled, they becoming growing beds for flowers, veggies, bananas, etc. Smaller pits become the future spots for fruit trees. All sorts of coarse material go into these pits, where it slowly breaks down via cold composting. Logs and tree chunks, woody brush, plus lots of seedy weeds, paper and other biodegradable trash, grass clippings, poor quality soil, rocks, manure, and the occasional dead animal not useable for something else. I'll also layer in wood ash, coral sand or burnt coral, and processed bones. 
7- Lasagna composting. Also known as sheet composting. My seed farm is a good spot for this method. Being predominantly lava rock, there is no way to turn anything in or over. So layers of organic material are laid down in sheets atop the rocky ground. One layer after the other. Cardboard/newspaper. Grass clippings. Macnut husks. Horse manure. Poor fertility soil. Wood ash. Coral sand or burnt coral. Biochar. Processed bones. Chipped brush. Water well and repeat. It will take years to create a deep soil bed, but there are areas already where I'm planting pineapples and sweet potatoes into these lasagna layers. 

By using various methods of composting, I have been able to get away from using commercial fertilizer. But just like buying commercial fertilizer, composting is something that needs to be done repeatedly, every season. Some gardeners fail because they dig in compost once, then never again. They forget to feed the soil, the worms, their plants. I reapply compost with every new crop, and for long season crops or heavy feeders, I will top dress compost using it like a mulch. In the banana patch, I spread a little compost every few months, using it as a mulch. No need to dig it in. 

People will also ask me what ingredients should go into making compost. Well, just about everything. Just use everything in moderation. And mix it up. Keep it moist but not wet. Keep it fluffy so that air can get in. Until you get to know what makes your piles work, follow the mantra of 50% green 50% brown. Green = fresh weeds, grass, fruits. Brown = dead leaves, dry grass, shredded paper. Another mantra that can help -- 50% wet, 50% dry. These mantras are just starting points. You'll need to make adjustments from there. If you pile heats up within a few days, a week at the most, then you are on the right track. Warmth is good. 

I see failures with others gardeners all the time. Most common mistake -- too wet. Too much fruit. Too much wet grass. Too much fresh manure. Too much garbage. Too much rain getting into the pile. Next most common mistake -- too coarse. Too many twigs. Big stems from old veggie plants. Entire old tomato plants. Entire palm fronds. That sort of thing. Third common mistake -- too dry. People forget to wet everything going into the compost pile. Or it starts to heat up then dries out. Composting comes to a halt. Or there are too many crisscrossing stems which allow big open dry spaces. 

I just remembered another mantra that helps -- hack, wack, and stack. Hack weeds, grass, brush, etc down. The wack it into pieces, bruising the stems and leaves. Now stack it into a pile. Add water. Cover it up with something like cardboard, a thick layer of grass clippings, or a tarp. 

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