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San Luis Obispo Ca

I am confused?! I have recently purchased some Alaska fertilizer all natural 9-4-4 made from fish, blood, bone and calcium and so on. Is this better then say a 30-10-10 from one of those salt based fertz like Miracle grow? Is a 9-4-4 equal to a 30-10-10? How does all that NPK stuff work. I see all kinds of different numbers. For my example, will I get the same reults for the growing phase with a 9-4-4 vs a 30-10-10? Confused!?

4/21/2005 7:04:10 PM

Liverpool , England

Right.....it's like this.....30-10-10 means that for the dosage of the fert you get 30 parts nitrogen, 10 parts phosphate and 10 parts potash. Now if you have it as 9-4-4 then the for the same dasge you only get 9 parts nitrogen, 4 parts phosphate and 4 parts potash meaning you need like twice the amount applied to get the same end result. Then there is always the trace elements which will vary with each fert.
Alun J

4/21/2005 8:01:43 PM

Garden State Pumpkins

Yikes! and I thought Alun only chased skirts!

4/21/2005 8:21:12 PM

[email protected]

The 30-10-10 is so high in analysis that it absolutely has to be derived from mineral elements such as Urea, MAP (or DAP) & Muriate of potash. These are all soluble elements that will be very quickly available & will not have much staying power. In the soil, these types of ferts might last 4-6 weeks. As foliar ferts the little bit that is absorbed will work quickly. But much will run off onto the soil during precipitation events. The rest will volatilize (gass off) & be lost so the overall amount one needs to apply might seem excessively high over the course of a growing season.

Assuming the 9-4-4 is derived solely from all natural organic ingredients, then the majority of the elements will be insoluble. Thus their foliar absorption will be quite minimal. But while they will be very slow to release what they contain, these fish/kelp/blood type elements will last a much longer time & there will be only minimal losses to leaching or volatilization. These materials also stimulate other biological processes in the soil which might be advantageous in some soils (ie; those lacking in organic matter).

To really have a handle on plant fertility one has to learn to "read the plants" & use the right tool at the right time. In other words, the most talented growers use both types of products at times most appropriate for their own situations.

4/21/2005 9:51:01 PM

the three numbers are percents as well. take the 30-10-10. That means that for every 100 pounds of fertilizer, there's 30 pounds of N, 10 pounds of P, and 10 pounds of K. That's 50 total. The other 50 pounds are inert ingredients.

4/21/2005 10:28:40 PM

Montoursville, PA

The organic sources I read say don't put anything in the soil that the three numbers total more than 10.

4/23/2005 3:45:32 PM

[email protected]

That number might be low Dwaine. Blood is usually 11% N. I think so long as OMRI certified ingredients are used, the numbers might still sneak over 10 once in a while.

4/23/2005 5:17:26 PM