hort.net Seasonal photo, (c) 2006 Christopher P. Lindsey, All Rights Reserved: do not copy
articles | gallery of plants | blog | tech blog | plant profiles | patents | mailing lists | top stories | links | shorturl service | tom clothier's archive0
Gallery of Plants
Tech Blog
Plant Profiles
Mailing Lists
    Search ALL lists
    Search help
    Subscription info
Top Stories
sHORTurl service
Tom Clothier's Archive
 Top Stories
Disease could hit Britain's trees hard

Ten of the best snowdrop cultivars

Plant protein database helps identify plant gene functions

Dendroclimatologists record history through trees

Potato beetle could be thwarted through gene manipulation

Hawaii expands coffee farm quarantine

Study explains flower petal loss

Unauthorized use of a plant doesn't invalidate it's patent

RSS story archive

Re: CULT: 6-10-10?


Your explanation of the interpretation of a standard chemical fertilizer
analysis is basically correct, but not quite exact. While the first number
in the analysis refers to the percent by weight of elemental Nitrogen (N)
in the fertilizer, the following two numbers express the oxide equivalent
of Phosphorus (P) and Potassium (K) in the fertilizer.

The oxide of Phosphorus is phosphate (P2O5). It contains 44% elemental
Phosphorus by weight. Therefore, you have to multiply the middle number of
the analysis by .44 to get the actual percent of Phosphorus in the

The oxide of Potassium is potash (K2O). It is 83% elemental Potassium by
weight. Therefore, you have to multiply the last number of the analysis by
83 to get the actual percent of Potassium in the fertilizer.

I do not know how this rather baroque system of expressing fertilizer
analysis became established, but it is still the standard used in labeling
chemical fertilizers.

Jeff Walters in northern Utah  (USDA Zone 4/5, Sunset Zone 2, AHS Zone 7)
> From: Birdwoman424@aol.com
> To: iris@hort.net
> Subject: Re: [iris] CULT: 6-10-10?
> Date: Thursday, May 01, 2003 9:17 PM
> In a message dated 5/1/2003 10:15:56 PM Eastern Daylight Time, 
> corgilover@wi.rr.com writes:
> > Maybe it would be easier for my if I knew what the last two numbers 
> > stood for.  I know the first is nitrogen . . . . .
> > -- 
> > Pat Mitchell
> > 
> nitrogen, phosphorus and potassium (also known as potash).
> example: 5-10-5 is 5% nitrogen, 10% phosphorus and 5% potassium (potash).
> The remaining 80% is filler.
> Nitogen - for rapid growth and green leaves
> Phosphorus - for root growth and develop strudy plants and flowering
> Potassium - for new cell growth, roots and buds

To sign-off this list, send email to majordomo@hort.net with the

 © 1995-2015 Mallorn Computing, Inc.All Rights Reserved.
Our Privacy Statement
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index