“An international nonprofit organization that determines which input products are allowed for use in organic production and processing.” Site includes a searchable database of products and fertilizers and their permissibility in organic agriculture.
Keyword: Organic fertilizers
Ammonium sulfate and organic guidelines
Is ammonium sulfate considered an organic fertilizer? I’d like to use some on my blueberries, but suspect it is not organic.
According to Fertilizers and Soil Amendments by Roy Hunter Follett (and others), ammonium sulfate is one of the oldest chemical fertilizers, and is “a frequent by-product of the steel industry, particularly the coking of coal.” That doesn’t sound like it meets organic guidelines. It is also tricky to use because it can cause phosphorus and aluminum to build up in the soil. The Organic Materials Review Institute lists it as a prohibited (for certified organic growers) synthetic crop fertilizer and soil amendment. You might do better using a slow-release certified organic fertilizer labeled for acid-loving plants. Cornell University Extension’s publication, Production Guide for Organic Blueberries” mentions fish, soy, and alfalfa meal as organic-acceptable amendments.
on organic fertilizers and soil amendments
I was wondering if you could provide me with a more or less exhaustive list of organic fertilizers and soil amendments, their nutrient profile, and what they are good for, etc.
When you say ‘organic’ fertilizer and soil amendments, do you mean those
items which are allowed under current organic regulations? I ask because
there is considerable difference of opinion over what is meant by the
word ‘organic’ in this context. Sewage sludge which contains heavy
metals could be said to be organically derived, but might not pass muster
in an organic garden, for example.
If you mean products which are on the Organic Materials Review Institute
list of permitted soil amendments, here is a link to their lists.
If you need a truly exhaustive list, I recommend looking at some of the
books available in the Miller Library on this subject. Rodale’s Illustrated Encyclopedia of Gardening and Landscaping Techniques edited by Barbara Ellis (Rodale, 1990) has a very easy-to-use (but probably not exhaustive) guide to soil amendments and fertilizers. Below are are some other titles:
Soils : the right way to use fertilizers, composts, soil conditioners,
soil testing/problem soils 1986
Let nature do the growing : the fertilizer-free vegetable garden / by
Gajin Tokuno c1986
Fertilizers and soil amendments / Roy H. Follett, Larry S. Murphy, Roy
L. Donahue
Fertility without fertilizers : a basic approach to organic gardening /
Lawrence D. Hills
Feeding plants the organic way / Jim Hay
Growing green: animal-free organic techniques / Jenny Hall and Iain
Tollhurst
The following links may be helpful to you:
Colorado State University Extension – Organic Fertilizers
National Sustainable Agriculture Information Service – Sources of Organic
Fertilizers and Amendments
University of California Santa Cruz Agroecology Program – Building Fertile Soil
Washington State University Extension – A Home Gardener’s Guide to Soils and Fertilizers
Oregon State University – Improving Garden Soils with Organic Matter
Garden Tip #119
Gardeners with a wood burning stove or fire place often wonder whether they can use the ash as a source of potassium. The answer is yes if only wood (and no glossy paper) was burned. Where and how much? That depends. Wood ash raises soil pH, so if you have acid soil use it on the vegetable garden where a neutral pH is preferred, but avoid shrubs that like acid soil, such as Rhododendrons and Camellias. Recommended amounts vary, from a cupful around rose bushes to 20 pounds per 100 square feet for slightly acidic soil. Always work it into the soil. Read more about wood ashes from Oregon State Extension