I have not seen the soil report to which you refer, but if it is a standard
soil test report there is probably no reason to try to convet the results
to other units. This is because most soil test analyses (except pH and
organic matter, in most cases) provide only a RELATIVE INDEX of nutrient
availablity, NOT an absolute quantity of available nutrient. Thus the best
you can do is to follow the interpretation of the numbers as puting the soil
in high, medium or low (etc.) categories for a particular nutrient and
ammend the soil in accordance with the lab's (or your Land Grant
Universities) experience from field experiments using crops grown on soils
with similar categories of soil test values. Your own experience with your
own soil should also figure in, but htere is not set, simple formula.
Twenty years ago the idea was circulating in certain books that nutrient
recommendations could be made on a prescription basis :.
amendment needed = plant uptake minus available in soil.
This interpretation of soil test results is unfounded and just plain wrong.
Hope this helps more than it confuses.
At 05:57 AM 1/7/97 -0800, you wrote:
>Hi y'all -
>I'm trying to understand my soil report and how I can amend my soil. My
>question to y'all is about converting parts per million to pounds per acre.
>Parnes in _Fertile Soil_ says to multiply ppm by 2 to find lbs/acre, for
>*soils of average density*. Amigo Cantisano from Peaceful Valley seems to
>be multiplying by 4 when calculating calcium requirements.
>So, what is soil density? How is it measured? Does it make a difference?
>Thanks, and Happy Epiphany!
Ray R. Weil
Professor of Soil Science
Department of Natural Resource Sciences
1103 H.J. Patterson Hall
University of Maryland
College Park, MD 20742
telephone: 301 405 1314
FAX: 301 314 9041