Nitrogen content of red clover plants

Includes the nitrogen content (mg) of 30 red clover plants inoculated with one of four single-strain cultures of Rhizobium trifolii or a composite of five Rhizobium meliloti strains, resulting in six treatments in total.

Usage

clover

Format

A tibble with 30 rows and 2 columns:

treatment

a factor denoting the treatment applied to each plant.

nitrogen

a number denoting the nitrogen content of each plant (milligrams).

Source

Steel, R., & Torrie, J. (1980). Principles and procedures of statistics: A biometrical approach (2nd ed.). San Francisco: McGraw-Hill. Available at: https://archive.org/details/principlesproce00stee

Details

Data originally from an experiment by Erdman (1946), conducted in a greenhouse using a completely random design. The current dataset was presented by Steel and Torrie (1980) and later used by Bautista et al. (1997) to illustrate their proposed procedure.

References

Bautista, M. G., Smith, D. W., & Steiner, R. L. (1997). A Cluster-Based Approach to Means Separation. Journal of Agricultural, Biological, and Environmental Statistics, 2(2), 179-197. doi:10.2307/1400402

Erdman, L. W. (1946). Studies to determine if antibiosis occurs among rhizobia. Journal of the American Society of Agronomy, 38, 251-258. doi:10.2134/agronj1946.00021962003800030005x

Examples

data(clover)
summary(clover)
#>      treatment    nitrogen    
#>  3DOk1    :5   Min.   : 9.10  
#>  3DOk13   :5   1st Qu.:16.07  
#>  3DOk4    :5   Median :19.25  
#>  3DOk5    :5   Mean   :19.89  
#>  3DOk7    :5   3rd Qu.:23.48  
#>  Composite:5   Max.   :33.00