C-Dax Pasture Meter, Assembly And Operation Manual

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Intercept
•
On your console the intercept is referred to as “ConSt”
•
The intercept relates to how much dry matter cannot be read by the sensor (i.e. is below
the bottom sensor)
•
If your calculated intercept = 750 this means:
o
750 kg DM/ha sits below the bottom sensor and cannot be read
o
When pasture height using the sensor 0 mm there is actually 750 kgDM/ha of
pasture residue
o
Pasture residue accumulates (increases) as grasses become more established
and/or the growing season becomes drier (i.e. moving from spring through to
summer).
Working Example
•
Slope “Factr” = 18.6, intercept “ConSt” = 750
•
Measured pasture height = 110 mm
Pasture height x Slope + Intercept = kgDM/ha
110 x 18.6 + 750 = 2796 kgDM/ha
During 2008, AgResearch, DairyNZ and Massey University with the support of Pastoral 21 Feeds
Program conducted extensive independent calibration of the C-Dax Pasture Meter on dairy
pastures throughout New Zealand. Pastoral 21 is funded by NZ Governments Foundation for
Research, Science and Technology (FRST), DairyNZ, Fonterra and Meat &Wool NZ.
Standardised trials were run in Northland (Dargaville), Waikato (Ruakura), Taranaki (Hawera),
Canterbury (Lincoln) and Southland (Wallacetown). The results of these trials are shown in the
table below.
Year Round Pasture Cover Equations Table
Use the following table to select the suggested Pasture Cover Equation:
Region Multiplier (FACTr) Constant (ConSt)
Northland 22.6 744
Waikato 16.3 700
Taranaki 21.8 827
Canterbury 18.1 729
Southland 17.7 825