Skip to Main Content
Replications and subsamples needed to show treatment responses on forest soils of the Coastal PlainAuthor(s): F. Thomas Lloyd; William H. McKee
Source: Soil Science Society of America Journal
Publication Series: Scientific Journal (JRNL)
Station: Southern Research Station
PDF: Download Publication (326.0 KB)
DescriptionThis research illustrates how randomized, complete-block designed field studies can be insensiti,e to detecting treatment-caused differences in the concentration of soil nutrients. An example shows that variation without compositing can be so large that 727 blocks are needed to be 90% confident of detecting a difference in total nitrogen of 100 μg g-1• Graphs are presented for determining the optimum numbers of blocks and chemical determinations per plot. The results show that compositing does not affect the number of chemical determinations per plot, but does reduce the number of blocks in direct proportion to the reduction in variance resulting from compositing. A hypothetical example shows that the number of blocks can be reduced from 727 to 15 by constructing blocks with less natural variation between treatment plots ad by compositing 20 sample cores for each chemical determination.
- You may send email to email@example.com to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationLloyd, F. Thomas; McKee, William H. Jr. 1983. Replications and subsamples needed to show treatment responses on forest soils of the Coastal Plain. Soil Science Society of America Journal. 47(3): 587-590.
Keywordssample size, type-II error, experimental design, variance, field trails, nitrogen
- Response of ectomycorrhizal fungus sporocarp production to varying levels and patterns of green-tree retention.
- Diversity and dynamics of arthropods and microbes, and nutrient release during green litter decomposition in a simulated hurricane experiment
- Development of Understory Vegetation in Pine and Pine-Hardwood Shelterwood Stands in the Ouachita Mountains-the First 3 Years
XML: View XML