Do not let the following discourage you from composting or just throwing plant material on the soil. Any organic matter added is better than none at all. As more knowledge is gained from nature we can then work with nature to maintain more of a natural balance. Ingham’s work at Oregon State University and Shigo’s work in Vermont, plus others, provides evidence that different ecosystems (e.g., Douglas fir forest, grass lands, etc.) require different sets of microorganisms in the soil for healthy plant growth. Hence the saying, “healthy soil, healthy plants, healthy people.”
Compost is wonderful “stuff,” even by not following the rules of the many compost books on the market. Poorly composted material is better than no compost at all. Plus you are doing the environment a favor by not adding materials to the local landfill.
From Ingham’s work comes the evidence that the garden and lawn does best with a bacteria, fungi ratio of 1:1. As we move toward a forest environment, the fungi numbers increase so that in a Douglas fir forest healthy soil has the ratio of 1 bacterium to 1000 fungi. Our home orchards have the ratio of 1 bacterium to 100 fungi. Thus we need to alter the method of composting for the backyard orchard.
Composting for the Garden
Composting for the garden, lawn, flowerbed, etc. follows most composting instructions, 50% green & 50% brown material.
To increase the number of bacteria we need to provide the food base for bacteria. In general, bacteria do not have the enzymes to digest complex carbohydrates so we need to provide the simple carbohydrates. The simple carbohydrates occur in green materials most of us have been using in composting. So the 50-50 green to brown is good, but for the backyard orchard we can do better.
Composting for the Home Orchard
I have not found any direct evidence in the literature to support what I am proposing, but it is theoretically valid. Woody plant materials favor fungi for decomposition. Therefore, composting with more woody materials will provide a food base for more fungi. Recall that the decomposition fungi will provide the food base for other fungi and organisms. Some of these fungi are going to be mycorrhizal fungi that are essential for healthy plant growth. I propose that we start building compost piles that incorporate 75 to 80% woody, brown materials. This will take longer to decompose, but the end result will be decomposed and partially decomposed material to add to your home orchard.
You now know what to do with all those prunings. Chip them clip them, break them or just lay them in a pile. Add some soil and 25-20% green material. Stand back and let nature do the work.
I even suggest that leaving the pruning limbs in the orchard is OK as long as they are not diseased and they are not a tripping hazard as you work around your trees.
Does Composting Need To Be Complete
The short answer is no. It is probably better to add compost that has not been completely composted to your garden, lawn, or orchard. Reason? Our concept of healthy soil is to have large diverse populations of soil microorganisms. These microorganisms need to eat. Completely composted materials add humus (excellent) but no food for the soil microorganisms. Some are suggesting that we just spread raw materials on the surface as nature does and do not make compost piles. This is called sheet composting. You be the judge. But the end result is that any organic matter added to the soil is better than none, so do not fret, just add to the soil. It is good.