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Date: | Fri, 5 Mar 1999 18:29:15 +0100 |
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Dear listmembers,
We will do this summer an experiment with clover and grass to study
N-cycle. For this we will use 15N-enriched fertilizer. Now, part of the
differences found between species may be due to inhomogeneity of the
fertilizer distribution in the soil (depth-trend) and species-dependent
rooting depth.
My first question: Did somebody already study the distribution of
N-fertilizer in the soil?
To partly reduce this problem, we thought of measuring delta15N of
plants grown under natural 15N conditions (no enriched fertilizer).
My second questions: Did anybody already such a study? How large are
natural 15N variations, 15N difference between air-N2 and soil N? How
large are the fractionations by built-in of N2, NO3,...?
Any help, references, ... would be helpful.
Thanks in advance,
Silvio Borella
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Silvio Borella /\
Klima- und Umweltphysik //\\
Phys. Inst., Uni Bern ///\\\
Sidlerstr. 15 ///\\\
CH-3012 Bern ////\\\\
Switzerland ///\\\
//II\\
Tel.: 031/631'44'70 II
Fax.: 031/631'44'05 II
e-mail: [log in to unmask] ********
http://www.climate.unibe.ch/~borella
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...common sense is nothing more than a
deposit of prejudices laid down in the
mind before you reach eighteen.
Albert Einstein
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