The test is used
to evaluate the potential stress of aluminum (Al) on forest tree species when
grown on soils with pH less than 5.5. The aluminum stress test is designed to
assist homeowners, park managers and others in optimizing woodlot management.
The test is a 0.01 M SrCl2 saturated paste extract in which the
plant-available concentrations of aluminum and calcium are determined. The
calcium to aluminum ratio is provided along with general guidelines relating
this ratio to the aluminum stress levels for tree species. Recommendations for
soil amendments, species selection for plantations, and forest regeneration
outcomes are provided with the test results.
For most applications, only the mineral soil horizons
containing the fine roots (less than 1mm in diameter) of trees
should be sampled. Care should be exercised to prevent organic
material including humus (usually black in color) from being
included in the sample.
To request this test, purchase a standard multiple soil test
kit from the county
offices of the Penn State Cooperative extension
and request an aluminum stress test submission form.
Submit your sample to the
laboratory with the aluminum stress test form. The fee listed is for the
aluminum stress test only and does not include fertility analysis.