Comparison of log transformed and scaled cone indices

Busscher, W.J. and Sojka, R.E. (1990) Comparison of log transformed and scaled cone indices. Soil & Tillage Research. 15:329-336.

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Abstract

Changes in soil properties with time and position make it difficult to analyze cone index data
taken throughout a growing season. It was hypothesized that scaling would aid in interpretation.
Cone indices were measured at 10 different dates over two growing seasons in conventional- and
conservation-tillage plots in Florence, SC. They were measured at 0.05-m depth intervals to a
depth of 0.55 m at spacings of 0.1 m across two 0.76-m wide rows of soybean or maize. Cone indices
were scaled by subtracting each value by the mean and dividing by the range of cone indices for
each date of measurement. This yielded an equal mean (zero) for each date with a unique distribution.
Unscaled values were transformed by taking their logarithm to normalize the data. Log
transformed data varied significantly with date of measurement but not between treatments. Scaled
values did not vary with date of measurement but did vary between tillage treatments. Both unscaled
and scaled cone indices varied significantly with water content. Scaling has the potential
to improve the analysis of cone index data by reducing or eliminating some of the confounding
treatment effects.

Item Type:	Article
NWISRL Publication Number:	0734
Subjects:	Mass Import - unclassified
Depositing User:	Dan Stieneke
Date Deposited:	20 Nov 2010 21:53
Last Modified:	09 Dec 2016 18:36
Item ID:	549
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/549