_Coffee grounds_ are nutrient-rich like other seed meals. Even after
brewing they can contain up to 2 percent nitrogen, about 1/2 percent
phosphorus and varying amounts of potassium usually well below 1
percent. Its C/N runs around 12:1. Coffee roasters and packers need
to dispose of coffee chaff, similar in nutrient value to used
grounds and may occasionally have a load of overly roasted beans.

Coffee grounds seem the earthworm's food of choice. In worm bins,
used grounds are more vigorously devoured than any other substance.
If slight odor is a consideration, especially if doing in-the-home
vermicomposting, coffee grounds should be incorporated promptly into
a pile to avoid the souring that results from vinegar-producing
bacteria. Fermenting grounds may also attract harmless fruit flies.
Paper filters used to make drip coffee may be put into the heap or
worm box where they contribute to the bedding. See also: _Paper._

_Corncobs_ are no longer available as an agricultural waste product
because modern harvesting equipment shreds them and spits the
residue right back into the field. However, home gardeners who fancy
sweet corn may produce large quantities of cobs. Whole cobs will
aerate compost heaps but are slow to decompose. If you want your
pile ready within one year, it is better to dry and then grind the
cobs before composting them.

_Cottonseed meal_ is one of this country's major oil seed residues.
The seed is ginned out of the cotton fiber, ground, and then its oil
content is chemically extracted. The residue, sometimes called oil
cake or seed cake, is very high in protein and rich in NPK. Its C/N
runs around 5:1, making it an excellent way to balance a compost
pile containing a lot of carboniferous materials.