Compost - Building Soils Naturally - page 108

Using Compost
The best time to apply compost is in the spring and fall when the conditions are best for
the microbes, although if you're doing intensive composting throughout the year, you may
apply it every month. In the spring, I apply it at least two weeks before planting to give
some time for it to get acquainted with the soil. You can apply compost in the fall, but if
you live in an area of high rainfall, you may want to cover your compost pile for the winter
and wait until the spring to apply it, in order to avoid leaching some of the valuable nutri-
ents from it.
If I'm using compost to make a new garden bed or install a new lawn in a soil without
much organic matter, I'll often till two to three inches of compost into the top 8-10 inches
of soil. That's generally too much compost to use more than once in the same garden, but
for a soil that is low in organic matter, it's useful to get that in there in the beginning. For
maintenance on existing beds, I'll apply between ⅛ inch and ¼ inch to the surface. I may
lightly incorporate it, but I don't do much tilling for maintenance. For an existing lawn, you
can screen out sticks and big clumps and apply it at ¼ inch thick. If possible, do this as of-
ten as in the spring and fall each year.
As I said, for maintaining nutrients and microbes, two to three inches is much more than
needed. The Luebke's, who developed Controlled Microbial Compost on their organic farm
in Austria recommend 10-12 tons per acre to start and then down to 3-8 tons for mainten-
ance. Elaine Ingham recommends a maximum of 10 tons per acre and more like 1-5 tons
per acre for maintenance. By my math, 12 tons per acre is only about ⅖ yard of compost
(⅛ inch thick) per 1,000 square feet and 1 ton per acre is only about seven gallons of com-
post (1/90 inch thick) per 1,000 square feet.
You can see that even a tiny amount of compost is beneficial, so you don't need to worry
about making or purchasing tons and tons. Instead, most home gardeners need only make
or buy 1 yard of high quality compost each year. While the organic matter is important to
get in there in the beginning, the nutrients and microbes may be the most important part
and even seven gallons of good compost can supply plenty of them. Many gardeners and
farmers apply too much compost, which results in nutrient imbalances, nutrient leaching
and subsequent pollution of our waterways, and volatization into the atmosphere as green-
house gases.
When planting trees and shrubs, rather than backfilling the hole with compost, amend
the entire planting area at least twice as wide as the planting hole by incorporating compost
into the soil. We want to enrich the soil, but we don't want to make the planting hole so
rich that the roots don't leave it. Finished compost can be used as part of a potting mixture
and for seed starting at about ⅓ compost, ⅓ sand and ⅓ soil. If possible, let this mixture
age for a month or two before planting into it.