A data frame with 256 observations on the following 10 variables.
X
a numeric vector with X-coordinates of the plot centres.
Y
a numeric vector with X-coordinates of the plot centres.
P
a numeric vector, phosphorous content.
PH
a numeric vector, soil pH.
K
a numeric vector, potassium content. (Cmol/dm^3)
MO
a numeric vector, organic matter. (percentage)
SB
a numeric vector, basis saturation.
iCone
a numeric vector, cone index, measuring mechanic
resistence of the soil. (kg/cm^2)
Rend
a numeric vector, total soya production within
the plot (kg).
PROD
a numeric vector, production converted to
productivity by a unit of area - hectare (ton/ha).