Organic Fertilizers Quick Reference Guide

Author Ellen Vande Visse

A Who’s Who of Amendment Choices

THE GOAL: build healthy soil with 3 M’s: Minerals, Microbes, & organic Matter. Select the lower application rate to maintain fertility. Apply the higher rate only for extremely poor soil. Calculate actual need from a soil test. Don’t guess. Too much is as harmful as too little.

Nitrogen or N Sources. Apply at a rate of pounds per 100 sq ft. Yep, math. Calculate your area and then amount needed per area.

Blood meal 12% From 1 to 4 lb

Fish meal 9-10% From 2 to 5 lb

Soybean meal 7% From 4 to 8 lb

Cottonseed meal 6% From 5 to 10 lb

Fishbone meal 6% From 2 to 5 lb —see note in P SourcesAlfalfa meal2-3%From 5 to 15 lb

Liquid Fish (emulsion or hydrolysate) Mix with water according to directions on label

Molasses (granular or liquid). Dilute about 20 parts water to 1 part molasses.
For activating compost pile, mix 5:1

Urine. Dilute 10- 20 parts water to 1 part urine. For activating compost pile, no dilution.

Phosphorus or P sources

Rock phosphate 33% Up to 10 lb

Bone meal 20% Up to 5 lb

Fishbone meal 6-10%. From 2- 5 lb. Note that FB meal is a 2-ingredient-in-1 application — N & P are both present. Compute application rate according to your need for N only.

Potassium or K sources.

Greensand 6-7% Up to 10 lb

Sul-Po-Mag = K-Mag22% =Langbeinite. Up to 6-7 lb Use only if deficient in Magnesium

Sulfate of Potash 50%. From 1/2–l lb

Wood ash. Varies w. wood burned. Apply only a light dusting to avoid severe rise in pH

Kelp meal 1.2%. Never use more than 1 lb/100 sq ft. So, choose another K source to go with the kelp meal, such as Sulfate of Potash or Greensand

OR, use the liquid form of kelp and apply every 14 days or so. Choose either Maxicrop Soluble Kelp Powder or Down to Earth’s Liquid Kelp & Potash 8 %. Mix according to package directions & apply as drench &/or foliar feed.

Note: most soils have adequate levels of K; add Ca and microbes to help release it and make it available to plants.

Fertilizers, Pre-Blended, Granular Form

Down to Earth All Purpose Fertilizer 4-6-2 in 6 lb box, or 25 lb bag

Sustane 8-2-4 in 5 lb box, or 20 lb bag or 50 lb bag

Sustane 4-6-4 in 5 lb box, or 20 lb bag, or 50 lb bag

Fertilizers, Pre-Blended Liquid Form

Vegetables: Down to Earth Liquid All Purpose 4-1-3, and Alaska Fish Fertilizer 5-1-1

Flowers: Down to Earth Liquid Bloom 2-6-4

Flowers: Alaska MorBloom 0-10-10

For flowers. Fox Farm liquid fertilizer

Also Earthworm castings, bat guano, kelp from beaches, rock dust

Others for a General Boost In Trace Minerals
Remember that these provide many trace minerals: compost, rock phosphate, kelp (with restraint), and various liquid fertilizers made from fish, seaweed, & even teas made from plants, such as nettles, horsetail, comfrey.

For a specific boost: Maxicrop, Azomite, Sea-90, and other sea mineral products.

To Build Organic Matter & Beneficial Microbes in the Soil Food Web

BioChar: Activate by soaking in compost tea or worm tea. Then apply at 5 to 15% by volume of potting soil or garden bed area.

Green Manures/Cover Crops: AK Mill’s own AK Soil Booster –the blend contains peas, fava, & oats. Sow with proper inoculant & grow. When crop reaches 2-5″ high, chop and cultivate back into soil. Effectively builds nitrogen, organic matter, & microbes right in place. Sow 100sq ft with 6lb seed; or 1000 sq ft with 60lb seed.

Compost: The first year, apply up to 3″ deep, or 1 cu. yd. per 100 sq. ft. Replenish compost annually at a rate of 1⁄2” depth.

Worm Castings: Mix 1 part castings to 3 parts potting soil or put a small amount into each transplant hole.

Actively Aerated Compost Tea: a highly effective way to fertilize, build soil food web, plus suppress disease. Apply 5-15 gal/acre. Available from Good Earth Garden School. Must be used within 8 hours or refrigerated up to 5 days. Dilute 5 parts de-chlorinated water to 1 part tea.

Soil ProVide with Soil ReVive: a new shelf-stabilized form of Actively Aerated Compost Tea with accompanying microbe food. This gives all the benefits of compost tea without brewing it. Just mix from package when you are ready to apply it. it over-winters well for a year or more. Available from https://www.earthfort.com/

Mulches of once-living matter like hay, straw, grass, leaves, needles, wood chips, sawdust, and compost

Home-made Organic Amendments

Coffee grounds (2% N): from Expresso stands. As mulch, worked into soil, or in your compost pile. It’s best if you can compost it first unless it is organic.

Compost- see above.

Manures from livestock: Apply about 50 lb or 4 cu feet or 1/2” per 100 sq. ft. It will contain weed seed.

Manure tea: soak manure in mesh bag in water barrel. Not as effective as actively aerated compost tea, but a good way to make manure spread farther without the weed seed problem of spreading solid manure, and avoids the weed seed factor.

Liquid calcium (eggshell extract). See the easy recipe.

Urine, human: dilute at least 10:1 up to 20:1 with water; otherwise it is too salty for plants & beneficial microbes.

Build healthy soil with 3 M’s: Minerals, Microbes, & organic Matter. Don’t kill your soil food web workers with inorganic fertilizers, herbicides, fungicides, or insecticides!