Early Composting Helps Soil and Plants Later
FOR IMMEDIATE RELEASE
April 11, 2014
URBANA, Ill. - New gardeners often
ask, "What is compost and do I need to buy it?"
When starting a new garden, it is
hard to imagine we should initially spend more time, money and energy on
compost than on plants, said a University of Illinois Extension horticulture
"It is plants we want," said Nancy
Pollard. "Yet without adequate compost (decomposed organic matter) in the soil,
the plants won't thrive. It is the soil that provides nutrients, and the
compost that holds adequate water and provides good drainage to make the
difference between just surviving plants and the thriving plants we covet."
soil, that is soil with a good amount of organic matter, will hold lots of
water available to plants, yet drain well so roots stay healthy. Soil can hold
roughly 1.5 quarts of water per cubic foot of soil for each percent of organic
matter. So increasing the organic matter content from 1 to 2 percent
would increase the volume of water to 3 quarts per cubic foot of soil, or at 3
percent to 4.5 quarts of water.
a difference that extra water makes in times of drought stress," she
said. "It is the difference between needing multiple applications of water
per week compared to only needing additional water every week or two. So
adding compost in the beginning saves you time and money and gets you much
better plants in the long run."
very small garden, work the organic matter in with a spading fork ($50- $100)
or for a larger garden, invest in a broad fork (about $200), Pollard
recommends. Many gardeners prefer the broad fork to a rototiller, as the broad
fork aerates more deeply, preserves soil structure, brings up fewer weed seeds,
cuts up far fewer earthworms, requires little maintenance, and is less costly
and less jarring.
much compost should be added?
recommends that for 100 square feet of soil, add one (or a proportional
combination of) the following:
- 8 cubic feet
of peat moss; OR
- 15 cubic
feet of compost; OR
- 4 bushels
(about six 5-gallon buckets) of grass clippings. (Do not use lawn
clippings from grass that has been treated with sprays containing
fungicides, insecticides, or herbicides.)
most un-decomposed organic matter is added to the soil, microbes begin
decomposing the carbon materials, utilizing soil nitrogen in the process. In
order to compensate for this nitrogen loss when using un-composted straw or
leaves, you will need to apply supplemental fertilizer containing nitrogen. For
100 square feet of soil, add either one bale of straw or four bushels of
leaves, as well as, in either case, 1 pound of nitrogen fertilizer (to help
microorganisms break down organic matter).
organic matter in the fall is best and the spring is second best. Any time of
year is better than not doing this, Pollard cautioned.
not say add garden soil or potting soil to your garden unless you are making
raised beds," she noted. "If using raised beds, create a soil and compost
mix with up to a maximum of 50 percent compost by volume. So you likely
don't need more soil in your garden, you likely need more compost.
are those extra quarts of water made available by organic matter
important? Water is critical because plants use water to maintain plant
turgor (hold them up). Water aids in cell division and growth; water
provides pressure to push roots through soil; water is required in
photosynthesis to make carbohydrates; water moves food and minerals around the
plant; and water is critical for stabilizing plant temperatures," Pollard said.
of compost initially and top dressing with compost annually means the plants
will likely have adequate water available and won't be stressed so easily. The plants
will flourish, and the gardener will be proud and proclaim they have a green
thumb! Interesting that brown matter (compost) is what makes for a green thumb!
Source: Nancy Pollard, Extension Educator, Horticulture, email@example.com