The new (three years) resin test here is more accurate on rock phosphate
fertilized soils, but still erratic.
Measuring tissue gives 15 accurate levels of elements. Soil test can't do this.
Where soil/tissue tests have been compared over years, tissue is shown to
be consistent, while soil tests are not.
You solution is to test what comes out of the soil and what the animal eats
- tissue. Optimum levels have been set for 40 years and the seasonal
variations are known.
Let me know through Sanet if more info is required, so that all get the
answers.
Vaughan Jones
>Hello to all,
>I am currently reading an article by E. Skogley of Montana State
>University titled Reinventing Soil Testing for the Future. This article
>was published in SSSA special publication 40, 1994.
>
>In this article Skogley begins by presenting that the current soil
>testing
>"system" is not meeting the needs of farmers and ag industry. He
>presents a graph showing total samples analyzed per year which shows a
>dramatic rise from 1950 to about 65' then a precipitous fall until about
>1975 then a rise to near maximum levels by 85 and then a drop off
>again... in 1993 1 soil sample was analyzed per 40 ha of crop land...
>
>I can think of a few explanations of this graph...
>
>1) After a decade + of intensive fertilizer use, soils began testing in
>the high range repeatedly and farmers decided to stop testing...
>2) Fertilizer prices were high and farm income was low during the 70s
>3) Soil testing was novel and highly promoted during the 50s and 60s...
>
>Skogley goes on to present that the current extraction based soil testing
>methodologies should be replaced by ion resin technology.
>
>In a nutshell, mixed bed ion exchange resin capsules placed
>incontact with moist soil for approximately 48 hours absorb
>nutrients in a way that mechanistically is much more similar to
>root uptake of nutrients and can be used to provide simpler, cheaper
>and more accurate soil fertility recommendations than current
>methodologies.
>
>Skogley is currently involved with side-by-side tests of ion
>exchange capsules and standard extraction methods. He is also involved
>with marketing ionexchange capsules...
>
>My questions for the list are:
>
>1) Are farmers and other consumers of soil testing satisfied with the
>current soil testing "system" ?
>
>2) Do we need to reinvent soil testing ?
>
>3) Are ionexchange resins the new wave of soil testing that will
>completely replace extraction methodologies ?
>
>I am working on the preliminary stages of a soil quality test based on
>the concept of active carbon being the foundation of soil quality...
>
>4) What other new soil test methodologies are soon to arrive on the scene
>?
>
>Joel Gruver
>U of MD, Agronomy
Best wishes,
Vaughan Jones
(retired dairy & beef farmer, consultant)
Hamilton
New Zealand
jonesv@wave.co.nz