HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Kravchenko, A. N. Articles by Robertson, G. P. Search for Related Content PubMed Articles by Kravchenko, A. N. Articles by Robertson, G. P. Agricola Articles by Kravchenko, A. N. Articles by Robertson, G. P. Related Collections Spatial Distribution Soil Organic Matter

Spatial Variability

Can Topographical and Yield Data Substantially Improve Total Soil Carbon Mapping by Regression Kriging?

^a Dep. of Crop and Soil Sciences, Michigan State Univ., East Lansing, MI 48824-1325
^b W.K. Kellogg Biological Station and Dep. of Crop and Soil Sciences, Michigan State Univ., Hickory Corners, MI 49060-9516

^* Corresponding author (kravche1{at}msu.edu)

Received for publication September 1, 2005. Accurate mapping of total soil C on the field scale is essential for evaluating efforts to sequester soil C and for providing individual producers with information on C sequestration potentials of their fields. Data on easily measured secondary variables that are strongly related to soil C are believed to be helpful in improving mapping accuracy. The objective of this study was to assess improvement in mapping accuracy due to dense topographical and long-term yield monitoring information. Approximately 1200 total C measurements at the 0- to 5-cm depth along with topographical and 7-yr crop grain yield data were collected at twelve 60- by 60-m plots at the Long-Term Ecological Research Site in Michigan. Total C was found to be significantly related to topography and 7-yr average standardized yield in all studied plots, with regression R² >0.5 in approximately half of the plots. Accounting for either topographical or yield information in regression kriging, however, produced only modest (<10%) improvement in mapping accuracy compared with ordinary kriging. Plots with promisingly strong relationships of total C with topography or yield were also found to be the ones where spatial distributions of total C were highly continuous, thus leading to no advantages in using regression kriging. The results indicated that under soil and topographical conditions similar to those of this study, dense topographical data or dense long-term yield data might not lead to substantial improvement in C mapping accuracy.

Abbreviations: CT, chisel-plowed management with conventional chemical inputs • CTcover, chisel-plowed management with a winter leguminous cover crop and no chemical inputs • NT, no-till management with conventional chemical inputs • N/S, nugget to sill ratio