nitrogen {GLMsData}

Soil nitrogen

Description

The soil nitrogen after applying different fertilizer doses

Usage

data(nitrogen)

Format

A data frame containing 24 observations with the following 3 variables.

Fert

the fertilizer dose, in kilograms of nitrogen per hectare; a numeric vector

SoilN

the soil nitrogen, in kilograms of nitrogen per hectare; a numeric vector

Source

the fertilizer source: a factor with levels 0 (inorganic) and 1 (organic; farmyard manure)

Details

The data give the soil inorganic nitrogen content for various fertilizer doses, including a control. One application is from an organic source. Each level of fertilizer has data from three replications.

Source

P. W. Lane (2002) Generalized linear models in soil science. European Journal of Soil Science, 53:241–251.

References

Glendining, M.J., Poulton, P.R. & Powlson, D.S. (1992) The relationship between inorganic N in soil and the rate of fertilizer N applied on the Broadbalk Wheat Experiment. Aspects of Applied Biology, 30, 95–102.

Examples

   data(nitrogen)
   summary(nitrogen)