----- Original Message -----
From: Roger Pye <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Saturday, October 19, 2002 7:38 PM
Subject: Re: Nutrient blockers
> Lloyd,
>
> Can we come back to aluminium/calcium ratios, please. Assuming the
> 'ideal' is 0:400, I want you to consider a scenario where a 'strip' of
> african lovegrass 2-4 metres wide weaves through undulating pastureland
> for a distance of approximately one km. The soil with the lovegrass when
> analysed shows an Al/Ca ratio of 100:150 whereas the ratio on both sides
> of the strip where there is no lovegrass indicates 0:350. The pH is
> around 5.5.
>
> I'm interested in what your conclusions would be in that situation.
>
> roger
Hi Roger
This is a bit of a trick question I think! I really should see
the site before commenting but lets excercise our imagination for a bit. I
am assuming the numbers you are using are from James? If so they would be
the result of a pendulum analysis? I dont have a problem there, I've seen
him use it close up, but depending on how he framed his questions and his
base knowledge of soil testing/analysis could put a different meaning on
ratios etc to what I am used to from hard chemistry tests.
The lovegrass could be something as simple as seed washed in
from offsite in previous seasons. It likes to grow in acid soil conditions
maybe it also can promote acidic soil solution by its root exudates?
There really could be a hundred explanations for this -
contamination from some chemical - say a spray tanker or sheep dip trailed
out across the paddock. A leaky bag of seed when the first lovegrass was
introduced to the area. A change in the subsurface structure. I get the
feeling that something is going on underground in this area but it really is
a puzzle. However like most puzzles there is probably a simple answer!
I would like to see conventional soil tests and if it was my
site I would do that sampling the lovegrass band separate from the other
area - still won't tell the cause though will it?
More later I think
Cheers
Lloyd Charles
>
