1aRothamsted Research, Harpenden, Hertfordshire AL5 2JQ, and bNational Soil Resources Institute, School of Applied Sciences, Cranfield University, Cranfield, Bedford, MK43 0AL, UK
Tóm tắt
SummaryThe soil is subject to change, and this must be monitored and understood. There are various circumstances in which the change in a soil property will depend in part on the baseline value that was first measured. Such a relationship may allow us to estimate change with greater precision, but it will also reflect in part the statistical phenomenon of regression to the mean. In this paper, we describe two approaches to the analysis of how change in a variable depends on its baseline values. These methods allow for the effect of regression to the mean. We discuss their applicability to the problems of soil monitoring, and we illustrate one of them by means of a case study on change in the organic carbon content of the soils of England and Wales.
Từ khóa
Tài liệu tham khảo
10.1038/nature04038
10.2307/2286454
Gilmour A.R., 2002, ASReml User Guide
10.1002/sim.4780070903
10.1111/j.1365-2389.2004.00637.x
10.1016/j.geoderma.2005.08.009
Oldham P.D, 1962, A note on the analysis of repeated measurements of the same subjects, Journal of Chronic Diseases, 26, 781
