What ever happened to the 1-0-0 NPK ratio idea?

[CaptainCompostAL]

I was reading one of HG's old organic gardening books from the mid-1990's, that was discussing the 1-0-0 NPK ratio idea. I wanted to know is this still a valid idea or has it been dismissed now with all the latest research in natural/organic farming?

For those of you who have never read the book, or don't know about this:
This idea basically states that the only real important nutrient that we need to keep track of is "available nitrogen". In a totally organic system, NPK ratios don't really make sense anymore. The tradition NPK ratios keeps track of soluble available NPK, not the total, insoluble NPK and micronutrients in all our composts and natural soil amendments.

Almost every nutrient and microbe you need for plants and soil, in found in all of our composting, cover crops, and organic mulches. Nitrogen is not only important for leafy, plant growth, but it is essential in microbial growth in composting and tea brewing. This nitrogen is usually in the form of proteins, ammonium, nitrites, and nitrates.

The 1-0-0 NPK ratio concept only keeps track of available N needs, not the available P and K needs. So with this new scheme, Fish meal (10-2-2) would look like (10-0-0). Bone meal (6-11-0) would (6-0-0). Homemade compost (1-1-1 to 4-4-4) would look like (1-0-0 to 4-0-0). And seaweed/kelp meal (0-0-1) would look like (0-0-0)! (LOL)

What do y'all think about this concept?

[drchelo]

Hmm...let me see if I understand here - what the 1-0-0 NPK ratio tells us is that nitrogen is the only variable that is subject to change, depending on the fertilizing mixture you are using, and let the organic process of de-composition take care of the potassium (K) and the phosphorus (P)? My question is this: for flowering plants and fruit, we have been told to use extra potassium along with thie nitrogen - to form flowering buds; and for root crops like onions and turnips, I have been taught that extra phosphorus is what is called for - why was I told that? What about pH and the relative availability of different micronitrients, like iron? What about Epsom Salts for Aunt Gussie's rosebush? She swore by her salts and blackstrap molasses (and a drop or two of kerosene) being the cure for whatever ailed animal, plant or child!
Am I just confused, Captain?

[CaptainCompostAL]

No, my friend, I personally don't think you are confused. I do the same thing. I'm just asking a hypothetical question on this subject.

This spring and summer, I basically mentally thought out all the types of crops that I was going to grow too. Instead of being exact in the concerns over exact available NPK, pH, etc. I just loaded tons of homemade compost over my 3/4 acres of no-till beds, that were green manured by large thick patches of legume/grain cover crops from the winter before.

Then I basically only added extra nitrogen in the form of fish emulsions for tall, leafy, green plants.

I added extra phosphorus in the form of bone meal, corn meal, or rotten bean seeds, to any heavy flowering or fruiting crops in the planting holes in the soil.

Then I added a little extra potassium in the form of wood ashes or strong kelp teas to my root crops like potatoes or carrots.

I added a little extra dolomitic limestone under each plants that I knew needed extra Ca and Mg in their leaves or fruit like tomatoes, eggplants, and melons.

I ever sprinkled extra Epsom salt, powdered sulfur, and corn meal over every tomato plant, just in case it might have a fungal disease problem later in the season. And it did, due to the excessive raining and flooding in my area.

However, I never check my soil pH any more, or I haven't had an expert soil tests in several years now. I probably need to, just to encourage myself on how my soil has drastically improved in 3 years from a no-till system. I used to have a hard, red, heavy clay soil with a pH=5.0. Now it's around pH=6.8, with a soft, crumbly, dark, grayish flour look and texture.

I also roughly adjust the nitrogen levels in my aerated teas based on what plants I'm feeding too. Heavy nitrogen feeders like corn, get more fish or aged horse manure or grass clippings in the tea recipe, or less water dilution at application time. Heavy phosphorus feeders like tomatoes, get more water dilution or less fish, more kelp in the tea brewing recipe.

[Dirt Doctor]

To answer your original question, the 1-0-0 idea from A&M and now pushed by Sperry is a very bad idea and based on a false premise - that most soils in Texas are too loaded with phosphorous. See my detailed answer in the Information Center under A&M.... and also Phosphorous. We will add Malcolm Beck's reply on the same subject right away.

[CaptainCompostAL]

Thanks, HG!

[CaptainCompostAL]

Here is the arctile HG was referring to:

http://www.dirtdoctor.com/view_question.php?id=351

This is very helpful! I use confused because I first saw HG mention this in his old 1990 book about the 1-0-0 NPK ratio suggestion. I had no idea that this was just a regional issue to Texan farmers, and not to the world of sustanable farmers.

I know that most Texan soil is very alkaline, and high in total phosphorus, while soil in my area of Alabama is mostly acidic, heavy clay.

I believe an abundance of mature compost, mulches, cover crops, and other sources of organic matter, plus biostimulants like aerated teas, will balance available P and K in all soil types, and all native soil pH levels, for growing plants.



Thanks again, HG!