Wednesday, October 10, 2012

Organic Fertilizers – Part 4 - Animal Sources

Animals Provide Organic Nutrients

Getting this article on Animal Sources organized today, I found that the animal sources for organic fertilizers are limited.  The products that come from animals are few, but I did find some really good quality fertilizers, and some – not so much.
Let’s look at the –not so much- products first.
Blood Meal   As the name implies, blood from animals is the ingredient of this product.  Slaughterhouse floors are scraped and the products is pulverized into powder.  Processing of cattle is the usual source, but pigs, and chicken blood can be used.  High in Nitrogen, Blood meal has an N-P-K of 12-0-0.  This type of nitrogen is readily available, and may burn plants if over applied.
In strict organic production, blood meal is not allowed to be fed to organic livestock.  The risk of mad-cow disease is the reason for this ban.  Applying blood meal to crops as a soil amendment is allowed however.  As a precaution, it is recommended that during application of blood meal, a mask is worn to limit exposure of this disease.

Blood Meal is also used as an animal repellant and as a compost accelerator.

As a readily renewable product, resources (blood) come from processing 26.4 Billion pounds of beef annually.  22.5 Billion pounds of pig products are produced annually.

bone meal  arbico
Bone Meal  The same industry as above, provides bone for organic bone meal. Bones are steamed, stripped, dried, and ground during processing.   Bone meal is high in phosphorus, and helps promote root growth in plants. Common use of bone meal is in the fall while planting spring flowering bulbs.

I recommend that indiscriminate application of any fertilizer be discouraged.  In the case of phosphorous, this element is not readily used,  (especially in soils of pH above 7)  and stays abundant in soil for a long time.  Over use can cause phosphorus to leach into the watershed, and cause algae bloom in area lakes.(Here again, I suggest a soil analysis, before applying amendments.)

There are alternatives to using bone meal and I will look into them in Step 5 – Ocean and Sea Products Used for Organic Fertilizers

Feather Meal  feather meal
Feather meal is also a by-product of the food industry, slaughtering poultry. It supplies a fairly good supply of Nitrogen. As  a slow release fertilizer, feather meal can provide nutrients for up to four months. Work powder into soil for decomposition to start.

poultry feather meal

Making feather meal is called rendering. The feathers are steamed to sterilize them and ground into a powder.

Poultry Litter   Poultry litter is a blend of poultry manure, feed, and bedding.  The nutrient values are 3-3-2.  It works best when worked into the soil.  Long-term benefits of this nutrition is evident even into the second year after application.  75% of N-P is available the first year.  The remaining 25% remains viable into the second year. The main cost of poultry litter is transportation to the marketplace, and the cost of applying it.  With so much litter available, this resource is being useful in another area – biofuel.


Example:  In the State of Minnesota, several farms that produce turkeys have found a way to dispose of tons of litter – 1.7 million tons, to be exact!  The litter is removed to a local power plant where it is burned in turbines, and generates thousands of KW hours of electricity.  This is enough electricity to power 60,000 homes!  The remaining ash of the turkey litter is returned to the farmers who use it as an organic fertilizer.  Win-Win – no mountains of litter piling up, no odor, and the resource is –indeed- renewable.

Manures   Animal sources of this organic product are several.  Horse manure – sometimes called mushroom compost – is used to top dress farms and gardens.  Cow manure – to me – is a better choice than horse manure. I’ve have found that cow manure is less likely to contain seeds that will gladly sprout all over the garden.  Since cows have a two stomach digestive system. the weed seeds are digested better.

Composted manures are starting that decomposition process, and nutrition is more readily available.

Bat Guano  Guano is another term for manure – of bats.  The three types of bats are sanguivorous – vampire bats that seek blood; the insectivorous bat who eats insects; and the fruit eater, the frugivorous bat.

bat eating fruitFruit eating bat
bat eating insectsInsect eating bat
deer bat - sean hall 5032 Blood eating bat

The blood eating and the insect eating bat guano is high in nitrogen and phosphorus.  The fruit eating bat guano has less nitrogen.  Therefore, when purchased, the label for Guano will indicate a Nitrogen Source, or a Phosphorous Source.
bat guanoArbico bat guano nitrogenArbico products

Guano extraction is bat friendly.
bat guano retreival

Tarps are collected after a week or so, and the guano is processed into fresh, fossilized, or semi-fossilized formats.  Macro- and micro-nutrients are available in huge amounts. These nutrients activate microorganisms in the soil.   Mix granular guano in holes when planting trees and shrubs, or apply to soil when planting grass seed.  A ‘tea’ can be made with guano, and used as a foliar spray as well.

Animal sources for organic fertilizers are readily available, but some concerns are noted.  What organic fertilizers do you use?  What do you  avoid?

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