Lately, I caught the compost fever and borrowed 3 books from the Library to learn about composting. My previous attempt more than 3 years ago was a total failure. The red wigglers were running away from the piles. This time I decided to study up all aspects of compost and make a gallant effort to do it right. A summary of what I learned:
What is compost?
It’s a rich mix of organic matter (humus), the natural decomposition of organic materials from piling mixtures of animal manure, plant debris, and soil.
Humus acts as a slow release fertilizer, hold soil particles together, help water retention, provides good drainage, present wind and water erosion, supports a wide range of soil bacteria including those that produce natural antibiotics to fight against plant disease, and moderates soil temperature.
How decomposition takes place: psychrophiles (low temperature 13C) bacteria digest the carbon compounds and raise the temperatures for the next group. Mesophiles, mid-temperature bacteria that thrive at about 20~30C. This contributes to the majority of the decomposition. Then the Thermofiles (high temperature 40~70C) will come next to sustain the final phase of decomposition. It’s followed by fungi such as actinomycetes and streptomycetes that produces natural antibiotics.
Compost benefits soils: 1) improves soil texture (turning clay to sand and then to lam), increases microbial activities, provides nutrition but not a fertilizer, adjust soil chemistry, buffers extremes of soil temperature.
Compost benefits plants: 1) reduces insect pests, 2) fights plant diseases. 3) discourages weeds.
How to compost?
Making the simple piles: enclosing the simple pile, add air, reduce the particle size, adding decomposing organism, adding commercial bioactivator products, adding worms, adding nitrogen
What to compost:
Nitrogen (green): alfafa, bone meal, coffee ground, fish scraps, grass clippings, raw kitchen garbage, chicken manure, cow manure, horse manure, human urine.
Both Nitrogen and Carbon: Leaves, rotted manure, washed seaweed, fresh weeds.
High Carbon (brown): Tomothy hay, paper, shredded newspaper, saw dusts, wheat straw, oat straw, wood chips.
What NOT to compost: sawdust from pressure-treated lumber, chips or sawdust from allelopathic trees (black walnut, eucalyptus, red cedar and others with aromatic oils), meat, dairy products, used pet litter or pet feces, human feces, ashes from a coal stove or charcoal ashes, diseased garden plants, grass clippings treated with pesticides or herbicides, invasive weeds, poison ivy.
Tips to speed up compost:
- Large enough pile (3′x3′x3′) to create a big enough critical mass for the compost to reach high temperature of 130F.
- Add enough nitrogen up to a ratio of 1:5 of N/C (nitrogen to carbon). Too much nitrogen invites smell. Optimal is 1:20.
How to use compost:
Use it in new areas: spread 2″~3″ with tiller over the top.
On existing lawn or garden beds.
Apply to trees and shrubs
Use it for transplants
Use it for starting seedlings
Use it in plant container (1/3 compost to peat moss, vermiculite, and perlite.
Replacement for compost: municipal leaf compost, municipal composted sludge, mushroom soil, peat moss and aged cow manure, Canadian Sphagnum peat moss.
Let it Rot
Composting: Hands On Gardener
Posted by Derek Tsai in Book Reviews