Getting Plant Food

Getting Suitable Plant Food

A fairly complete listing and analysis of commercial and organic fertilizers can be found in Alexander Bedoe's book Nourishment Homegrown (available from Medical Missionary Press, 491 Blue Hill Road, Marshall, NC 28753, for $30.00 + shipping cost). Here is a listing of the main elements widely available that are recommended for use in biological gardening (compatible with sustainable soil practices that encourage soil micro-organisms, and help produce the greatest level of possible nutrition in the produce). The percentage rating indicates that out of 100 lbs of the material the percent equals the number of lbs. of the plant food contained in it. If you are needing 5 lbs. of nitrogen for 1000 square feet of garden for example, then you would use approximately 15 lbs. of ammonium nitrate (34% nitrogen) and spread it evenly over the 1000 square feet. Or you could use cottonseed meal (6% nitrogen) at the rate of about 90 lbs. per 1000 square feet. One thing to remember is that most organic soil amendments (unless they are liquid) take much longer to break down and become available to the plants. You may wish to use a combination of readily soluble forms and organic forms to accomplish initial results, and still work toward a more strictly organic approach. The commercial fertilizers we have listed here can be used in biological gardening, if used carefully and not indiscriminately. They are not a substitute for the addition of organic soil amendments, but rather as supplements, a temporary “quick fix” while you are getting established. They may also be needed where a deeply entrenched deficiency exists, until you get it corrected. It can take a number of years to get soil developed to optimum fertility for both short term and long term. We can think of the “long term” as being the savings account to which you keep adding for future need, and the “short term” could be compared to the interest which you can access for immediate need. The “long term” requires weathering and microbe action to break it down into forms that will be available to the plant for its immediate use.

Nitrogen

Organic sources (remember that manures should be either composted, or spread at least 3-4 weeks before planting)

Soybean Meal - 7% nitrogen

Alfalfa Meal - 3% nitrogen

Worm Castings - 1.5% nitrogen

Feather Meal - 13% nitrogen

Chicken Manure Compost - 6% nitrogen

Blood Meal - 15% nitrogen

Canola Meal - 5% nitrogen

Fish Meal - 10% nitrogen

Fish Emulsion - 4% nitrogen

Kelp Meal - 1% nitrogen

Cow Manure - 0.5% nitrogen

Horse Manure - 1% nitrogen

Garden Compost - 1% nitrogen

Chilean Nitrate - 15% nitrogen

Commercial sources

Ammonium Nitrate - supplies both short term and long term nitrogen release. Use early in the season. 34% nitrogen

Ammonium Sulfate - 21% nitrogen (brown granules are best, rather than white)

Calcium Nitrate - 15.5% nitrogen (also supplies calcium, this is a good source of nitrogen to use)

Mono-ammonium Phosphate - 12% nitrogen (use sparingly in mix with other ingredients, this also supplies 20-45% phosphorous)

Potassium Nitrate - 14% nitrogen (also supplies 45% potassium)

Phosphorus

Organic sources

Soft Rock (Colloidal) Phosphate - 15-25% phosphate (slow release; also supplies 30% calcium)

placeStateTennessee Brown Phosphate - 35% phosphate (up to 13% initially available)

Bone Meal - 25-30% phosphate

Fish Emulsion - 2% phosphate

Fish Meal - 5% phosphate

Hard Rock Phosphate - 10-20% (extremely slow release)

Commercial sources

Mono-Ammonium Phosphate - 45-50% phosphate (use sparingly in mix with other ingredients, this also supplies 12% nitrogen)

Single Super Phosphate - 21% phosphate (made with sulfuric acid; this is very difficult to find now in the USA)

Potassium

Organic sources (please note that most all decaying vegetation will supply potassium)

Alfalfa Meal - 3% potassium

Green Sand - 8% potassium (slow release)

Hardwood Ashes - 10-15% potassium

Sawdust - 4-8% potassium (sawdust requires added nitrogen to break down)

Cow Manure - 0.5% potassium

Horse Manure - 0.6% potassium

Used Mushroom Compost - 0.8% potassium

Chicken Manure - 1.4% potassium

Commercial sources

Potassium Sulfate - 50% potassium

Potassium Nitrate - 45% potassium (also supplies 14% nitrogen)

Calcium

Organic sources (the limes listed below in the commercial section are also considered to be organic amendments)

Beet Lime - 38% calcium (byproduct of the beet sugar industry)

Bone Meal - 28% calcium (also supplies phosphorous)

Araganite -

Soft Rock Phosphate - 30% calcium (also supplies phosphorous)

Commercial sources

High Calcium Lime - 38% calcium (this has less than 5% magnesium; this is the best kind of lime to use for heavy clay soils)

Agricultural Lime - 35% calcium (can also contain over 5% magnesium; see note on Dolomite Lime)

Dolomite Lime - 30% calcium(can contain as much as 30% magnesium; avoid using this unless you have extremely sandy soil)

Hydrated Lime (also called slaked lime) - 54% calcium (use only in the fall when applying to the ground)

Calcium Sulfate (also called Gypsum) - 23% calcium (also supplies sulfur, which most soils need; this does not raise soil pH as do other liming materials)

Calcium Nitrate - 20% calcium (also supplies 15.5% nitrogen)

Minor Elements and Trace minerals

These are available in varying quantities in compost, manures, and other organic supplements. Below we will give the sources available commercially.

Copper

Commercial sources

Copper Sulfate - 25% copper

Sulfur

Commercial sources

Elemental Sulfur - 90% sulfur (this should be used in the fall)

All Sulfate fertilizers such as Calcium Sulfate, Potassium Sulfate, Copper Sulfate, Ferrous Sulfate (supplies iron and sulfur), Manganese Sulfate, Zinc Sulfate, etc. It is generally safe to use all sulfate fertilizers that you obtain commercially.

The following fertilizers will supply sulfur in the sulfate form in the following amounts:

Calcium Sulfate (Gypsum) - 16% sulfate

Ferrous Sulfate - 11% sulfate

Ammonium Sulfate - 24% sulfate

Single Super Phosphate - 12% sulfate

Potassium Sulfate - 18% sulfate

Sulfate is about 1/3 sulfur.

Iron

Commercial sources

Ferrous Sulfate - 20% iron

Manganese

Commercial sources

Manganese Sulfate - 24% manganese

Zinc

Commercial sources

Zinc Sulfate - 31% zinc

Boron

Commercial sources

Twenty Mule Team Borax - 11% boron

Solubar - 20% boron

Iodine, Vitamin B-1, Vitamin B-12, cobalt sulfate

(these can all be used in small amounts, mixed with water, and sprayed on the garden)

Commercial sources - locate by name

Note: Kelp Liquid or Meal, and feed grade Blackstrap Molasses are both excellent sources of miner elements and trace minerals. Mix with water and spray, or water plants.