Dear Peter,
do you have thought about homogeneity of your samples??? Especially soil samples
have to be ground very thoroughly, depending the weight you are using. Is it
true that the samples more reproduable, i.e. the samples having smaller standard
deviation are those ground finer than the other ones???
Kind regards
Bruno
Dr. Bruno Glaser
Institute of Soil Science and Soil Geography
University of Bayreuth
D-95440 Bayreuth
Germany