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.
Most cottonseed meal is used as animal feed, especially for beef and dairy cattle. Purchased in garden stores in small containers it is very expensive; bought by the 50-to 80-pound sack from feed stores or farm coops, cottonseed meal and other oil seed meals are quite inexpensive. Though prices of these types of commodities vary from year to year, oil cakes of all kinds usually cost between $200 to $400 per ton and only slightly higher purchased sacked in less-than-ton lots.
The price of any seed meal is strongly influenced by freight costs. Cottonseed meal is cheapest in the south and the southwest where cotton is widely grown. Soybean meal may be more available and priced better in the midwest. Canadian gardeners are discovering canola meal, a byproduct from producing canola (or rapeseed) oil. When I took a sabbatical in Fiji, I advised local gardeners to use coconut meal, an inexpensive "waste" from extracting coconut oil. And I would not be at all surprised to discover gardeners in South Dakota using sunflower meal. Sesame seed, safflower seed, peanut and oil-seed corn meals may also be available in certain localities.
Seed meals make an ideal starting point for compounding complete organic fertilizer mixes. The average NPK analysis of most seed meals is around 6-4-2. Considered as a fertilizer, oil cakes are somewhat lacking in phosphorus and sometimes in trace minerals. By supplementing them with materials like bone meal, phosphate rock, kelp meal, sometimes potassium-rich rock dusts and lime or gypsum, a single, wide-spectrum slow-release trace-mineral-rich organic fertilizer source can be blended at home having an analysis of about 5-5-5. Cottonseed meal is particularly excellent for this purpose because it is a dry, flowing, odorless material that stores well. I suspect that cottonseed meal from the southwest may be better endowed with trace minerals than that from leached-out southeastern soils or soy meal from depleted midwestern farms. See the last section of Chapter Eight.
Some organic certification bureaucracies foolishly prohibit or discourage the use of cottonseed meal as a fertilizer. The rationale behind this rigid self-righteousness is that cotton, being a nonfood crop, is sprayed with heavy applications of pesticides and/or herbicides that are so hazardous that they not permitted on food crops. These chemicals are usually dissolved in an emulsified oil-based carrier and the cotton plant naturally concentrates pesticide residues and breakdown products into the oily seed.
I believe that this concern is accurate as far as pesticide residues being translocated into the seed. However, the chemical process used to extract cottonseed oil is very efficient The ground seeds are mixed with a volatile solvent similar to ether and heated under pressure in giant retorts. I reason that when the solvent is squeezed from the seed, it takes with it all not only the oil, but, I believe, virtually all of the pesticide residues. Besides, any remaining organic toxins will be further destroyed by the biological activity of the soil and especially by the intense heat of a compost pile.
What I personally worry about is cottonseed oil. I avoid prepared salad dressings that may contain cottonseed oil, as well as many types of corn and potato chips, tinned oysters, and other prepared food products. I also suggest that you peek into the back of your favorite Oriental and fast food restaurants and see if there aren't stacks of ten gallon cottonseed oil cans waiting to fill the deep-fat fryer. I fear this sort of meal as dangerous to my health. If you still fear that cottonseed meal is also a dangerous product then you certainly won't want to be eating feedlot beef or drinking milk or using other dairy products from cattle fed on cottonseed meal.
Blood meal runs 10-12 percent nitrogen and contains significant amounts of phosphorus. It is the only organic fertilizer that is naturally water soluble. Blood meal, like other slaughterhouse wastes, may be too expensive for use as a compost activator.
Sprinkled atop soil as a side-dressing, dried blood usually provokes a powerful and immediate growth response. Blood meal is so potent that it is capable of burning plants; when applied you must avoid getting it on leaves or stems. Although principally a source of nitrogen, I reason that there are other nutritional substances like growth hormones or complex organic "phytamins" in blood meal. British glasshouse lettuce growers widely agree that lettuce sidedressed with blood meal about three weeks before harvest has a better "finish," a much longer shelf-life, and a reduced tendency to "brown butt" compared to lettuce similarly fertilized with urea or chemical nitrate sources.