Subject: Q. Interpreting Soil Analyses

From: [email-masked] (David JD Bell)
Date: Fri, 06 Sep 1996 07:41:40 GMT

I have been trying to convert the results of our recent soil analyses
into fertilizer rates.

I can follow the lab results, and I have the recomendations for our
crop (macadamias), so I can work out where there are deficiencies.
Having got that far, I find I can not convert these deficiency rates
into remedial fertilizer rates.

The problem is a question of units. The lab we use reports either
mg/kg or meq/100g for the various elements, but for working out
fertilizer application rates I have to convert these to Kg/Hectare.

I understand that there are tables of conversion factors for each
element (and maybe soil type etc), but when I asked our fert rep he
told me this was patented information! I think this sort of infomation
must be somewhere in the public domain, so if anybody knows where, I
would appreciate any assistance.

Thanks in advance.
|   ___/\                         | David JD Bell              |
|  /     \                        | Hidden Valley Plantations  |
| (  __  ') <- Look, there he is! | Beerwah, Qld, AUSTRALIA.   |
|  \/  \_/                        | [email-masked] |

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From: "Carl H. Hovermale" <[email-masked]>
Date: Fri, 6 Sep 1996 07:50:08 -0500

any lab that I know of gives fertilizer recommendations when they do the
test.  If they didn't what would be the use of dealing with them?

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From: [email-masked] (R.J.(Bob) Evans)
Date: Sat, 14 Sep 1996 02:58:58 GMT

On Fri, 06 Sep 1996 07:41:40 GMT [email-masked] (David JD

>into remedial fertilizer rates.

Which simply points up why we need labs to provide recommendations.
Soil testing and nutrient recommendation is more than simply buying
lab equipment.  There are two distinct components to the process:
1) Analyze the dirt.  This is relatively simple - any junior chemistry
set will do an acceptable job and more $$ spent on equipment only
serves to increase the number of figures to the right of the decimal
point.
2) Provide a recommendation.  This is where the human element enters
the equation.  To make a recommendation requres a database of expected
yield vs. tested nutrient status.  To complicate the issue the
database will not necessarily work across different soil parent
materials and will vary for different crops and often for varieties
within crops.  

Good luck.

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From: Dale Wagner <[email-masked]>
Date: Sun, 15 Sep 1996 12:58:28 -0700

R.J.(Bob) Evans wrote:
> Good luck.The book 'Using Commercial Fertilizers by Vickers' would help you understand 
the proscess.  The labs I used sent back the rates needed for different levels 
of production.  Maybe you are just using the wrong lab.  By going through a 
fertilizer company, you should be able to come up with this info.