Result of an experiment conducted to investigate the effect of salinity level in soil on the growth of plants.
A data frame with 24 observations on the following 3 variables.
amount of salt applied to the plot (in parts per million)
total biomass of plot at the end of the study period (units unknown)
field in which the plot was located
From the source (see below): "Experimental fields of land were located at an agricultural field station, and each field was divided into six smaller plots. Each of the smaller plots was treated with a different amount of salt (measured in ppm) and the biomass at the end of the experiment was recorded."