Jacobsen et al. (2002) sent nine "identical" soil samples to eight soil testing
laboratories in the Great Plains region of the Central United States over a three year period of time.
Among other characteristics the labs were paid to measure soil potassium.
A question of interest was whether the labs would produce identical analytical results.
Usage
data(K)
Arguments
source
Jacobsen, J. S., Lorber, S. H., Schaff, B. E., and C. A. Jones (2002) Variation in soil
fertility test results from selected Northern Great Plains laboratories. Commun. Soil Sci. plant Anal., 33(3&4): 303-319.