Understanding The Pasture Calibration Process; What Do The Values Mean - C-Dax pasture meter+ Operation Manual

Understanding the Pasture Calibration Process

Calibration Equations are used to convert the raw sensor measurement, pasture height
(reordered in mm), to pasture cover (kgDM/ha).
There are several ways to do this; these include comparing your height reading with:
o Calibration cuts
o Visual assessment
o Rising Plate Meter
A calibration equation is most commonly expressed as a straight line formula, a straight
line formula has two parameters slope of the line (m) and where the line intercepts the y
axis of a graph (c) (see below).
The parameters are used to convert pasture height to pasture dry matter using the
formula below:
kgDM/ha = Pasture height x Slope + Intercept
N.B. Use the form on the previous page to calculate both Slope and Intercept for your
equation.

What do the Values Mean?

Slope
•
On your console the slope is referred to as "FACtr"
•
The slope measures how much dry matter (expressed as kgDM/ha) there is per increase
in measured unit (i.e. mm).
•
If your calculated slope = 18.6 this means:
o
For every 1 mm increase in pasture height there is an increase of 18.6 kgDM/ha.
o
Therefore if the difference in pasture height was 10mm then the difference in
pasture drymatter is 186 kgDM/ha.
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