Composting

What does it have to do with water quality?

When you compost your garden waste and other kitchen scraps, you are reclaiming the nutrients contained in this material. When you use the composted material on your lawn and garden, you can eliminate the need for chemical fertilizers.  Chemical fertilizers are highly soluble, and a heavy rain will wash away much of these chemicals into our lakes and streams.  High levels of nitrogen in the water will do serious damage to the aquatic ecosystem. The result can be out of control algae growth, which in turn lowers the dissolved oxygen in the water. During hot weather, when dissolved oxygen is normally low, this can cause a die off the fish.

Lake Robinson, and its surrounding watershed, is not currently in this kind of danger. But the fact is, more and more people are moving into the area, and as this happens we will be putting a greater stress on the local environment. Composting is just one small step in the right direction.

What is compost?

In brief, compost is the rich humus like product of decomposition. It is what remains when a pile of organic material decays. 

All households generate excess organic mat­ter, such as kitchen scraps, grass clippings, leaf piles, and debris from pruning and cleaning up a yard full of plants. Most of this can be recycled right on site, and turned into a valuable source of nutrients for your plants.

What kinds of composting are there?

The three main kinds of composting are; compost pile, sheet composting and worm composting. In this article I will concentrate on the compost pile, which is what most of us think of when we talk of composting. I will discuss the others in future articles.

What does it take?

If you’re not too fussy, you can simply pile the stuff in the corner of your yard and wait a few months, and you will have compost.  It is possible, however, to be much more efficient. The critical elements of a good compost pile are the right ratio of carbon to nitrogen, optimum moisture, and proper size.

All organic materials contain carbon and nitrogen. The ratio of carbon to nitrogen (C:N) varies with each ingredient, and although eventually almost anything organic will decompose, an overall ratio of 30:1 C:N is ideal. It is possible to look up the C:N ratio of each ingredient in the compost pile and calculate the resulting ratio, but here's a good rule of thumb: Green materials, such as grass clippings, fresh plant trimmings, and kitchen waste, are high in nitrogen. Brown items, such as dried leaves, hay, straw, and wood shavings, are high in carbon. Manure is high in nitrogen, so for our purpose, we will consider it green. If you mix roughly half green with half brown you will be close to the ideal 30:1 C:N ratio.  You should not include any meat or dairy waste in the compost pile, as they will attract unwelcome animal scavengers.

The decay of the materials in the compost pile is the result a wide verity of living organisms. These organisms need water to survive. A good compost pile should be about as moist as a wrung out sponge, so keep a garden hose handy when building your compost pile. It can take an astonishing amount of water, if you start with dry ingredients. It’s a good idea to cover the compost pile with a tarp to retain moisture, and to keep rain from leaching out the hard won nutrients.

The size of the compost pile is important, because it will not reach the critical temperature of 130 to 150 degrees Fahrenheit if it is smaller than 3 feet on a side; temperatures in this range are necessary in order to sterilize weed seeds.  You should thus save up your materials until you have enough for a 3-foot heap.

Many people ask the question, should I turn the pile or not. If you're in a hurry for compost, turn the pile as soon as it’s initial blast of heat begins to subside. This will infuse the pile with oxygen and reinvigorate it’s occupants. Each time the pile starts to cool, turn it again. Using this method, a properly made compost pile will be done in about three weeks. Although this method produces mulch that is great for soil texture and moisture retention, it is not high in nutrients.

A less-turned pile won't rot down as quickly as a more ambitiously forked one, but it will provide your plants with nutrients longer than the product of rapid turnings. Slowly rotted compost still gets hot enough during that first heating to kill weed seeds, so weeds are not a concern. A good rule is, turn for texture when you need to build soil struc­ture, but rest the pile for long-term nutrition.

The best role for compost, as I see it, is to give a quick fertility boost to a limited area of soil. If you've just started to a new garden and want productivity quickly, then compost will improve soil fertility rapidly. An inch or two of compost lightly spaded into poor soil, or if you've got enough, sev­eral inches on top of depleted or compacted earth, will support very dense plantings. With plant pro­duction jump-started this way, a gardener can begin more long-term soil building.