One of the things I enjoy most while gardening is GROWing some of my
plants. I don't GROW them all because there is no point in having
giant parsley or making the corn patch get one foot taller. Making
everything get as large as possible wouldn't result in maximum
nutrition either. But just for fun, how about a 100-plus-pound
pumpkin? A twenty-pound savoy cabbage? A cauliflower sixteen inches
in diameter? An eight-inch diameter beet? Now that's GROWing!
Here's how. Simply remove as many growth limiters as possible and
watch the plant's own efforts take over. One of the best examples
I've ever seen of how this works was in a neighbor's backyard
greenhouse. This retired welder liked his liquor. Having more time
than money and little respect for legal absurdities, he had
constructed a small stainless steel pot still, fermented his own
mash, and made a harsh, hangover-producing whiskey from grain and
cane sugar that Appalachians call "popskull." To encourage rapid
fermentation, his mashing barrel was kept in the warm greenhouse.
The bubbling brew gave off large quantities of carbon dioxide gas.
The rest of his greenhouse was filled with green herbs that flowered
fragrantly in September. Most of them were four or five feet tall
but those plants on the end housing the mash barrel were seven feet
tall and twice as bushy. Why? Because the normal level of
atmospheric CO2 actually limits plant growth.
We can't increase the carbon supply outdoors. But we can loosen the
soil eighteen to twenty-four inches down (or more for deeply-rooting
species) in an area as large as the plant's root system could
possibly ramify during its entire growing season. I've seen some
GROWers dig holes four feet deep and five feet in diameter for
individual plants. We can use well-finished, strong compost to
increase the humus content of that soil, and supplement that with
manure tea or liquid fertilizer to provide all the nutrients the
plant could possibly use. We can allocate only one plant to that
space and make sure absolutely no competition develops in that space
for light, water, or nutrients. We can keep the soil moist at all
times. By locating the plant against a reflective white wall we can
increase its light levels and perhaps the nighttime temperatures
(plants make food during the day and use it to grow with at night).
Textural improvements from compost depend greatly on soil type.
Sandy and loamy soils naturally remain open and workable and sustain
good tilth with surprisingly small amounts of organic matter. Two or
three hundred pounds (dry weight) of compost per thousand square
feet per year will keep coarse-textured soils in wonderful physical
condition. This small amount of humus is also sufficient to
encourage the development of a lush soil ecology that creates the
natural health of plants.
Silty soils, especially ones with more clay content, tend to become
compacted and when low in humus will crust over and puddle when it
rains hard. These may need a little more compost, perhaps in the
range of three to five hundred pounds per thousand square feet per
year.
Clay soils on the other hand are heavy and airless, easily
compacted, hard to work, and hard to keep workable. The mechanical
properties of clay soils greatly benefit from additions of organic
matter several times larger than what soils composed of larger
particles need. Given adequate organic matter, even a heavy clay can
be made to behave somewhat like a rich loam does.
Perhaps you've noticed that I've still avoided answering the
question, "how good is your compost?" First, lets take a look at
laboratory analyses of various kinds of compost, connect that to
what they were made from and that to the kind of growing results one
might get from them. I apologize that despite considerable research
I was unable to discover more detailed breakdowns from more
composting activities. But the data I do have is sufficient to
appreciate the range of possibilities.
Considered as a fertilizer to GROW plants, Municipal Solid Waste
(MSW) compost is the lowest grade material I know of. It is usually
broadcast as a surface mulch. The ingredients municipal composters
must process include an indiscriminate mixture of all sorts of urban
organic waste: paper, kitchen garbage, leaves, chipped tree
trimmings, commercial organic garbage like restaurant waste, cannery
wastes, etc. Unfortunately, paper comprises the largest single
ingredient and it is by nature highly resistant to decomposition.
MSW composting is essentially a recycling process, so no soil, no
manure and no special low C/N sources are used to improve the
fertilizing value of the finished product.
Municipal composting schemes usually must process huge volumes of
material on very valuable land close to cities. Economics mean the
heaps are made as large as possible, run as fast as possible, and
gotten off the field without concern for developing their highest
qualities. Since it takes a long time to reduce large proportions of
carbon, especially when they are in very decomposition-resistant
forms like paper, and since the use of soil in the compost heap is
essential to prevent nitrate loss, municipal composts tend to be low
in nitrogen and high in carbon. By comparison, the poorest home
garden compost I could find test results for was about equal to the
best municipal compost. The best garden sample ("B") is pretty fine
stuff. I could not discover the ingredients that went into either
garden compost but my supposition is that gardener "A" incorporated
large quantities of high C/N materials like straw, sawdust and the
like while gardener "B" used manure, fresh vegetation, grass
clippings and other similar low C/N materials. The next chapter will
evaluate the suitability of materials commonly used to make compost.