Question:
I need to enter the percentage of plantain in a mixed pasture. How do I assess this, and how do I deal with variable plantain content between paddocks? How do I enter a plantain monoculture if it is grazed alongside other paddocks, e.g. for a few hours each day?
Answer:
DairyNZ have developed easy-to-use guidance for the visual assessment of plantain content in pasture that farmers and Regional Councils can have confidence in. The guidance is to help farmers estimate the average percentage of plantain for the various management blocks on their farm and enter this into OverseerFM and can be found on the DairyNZ website HERE.
The guidance involves using photos to assess the plantain content in each paddock on the farm in autumn and calculating the weighted average for the relevant pasture block. Examples of how this is done are given below.
Depending on the feedback received of the various ways farms might implement plantain and of new research results becoming available, these guidelines for data entry may be adjusted by DairyNZ.
Example 1
A farm has introduced plantain in a pasture mixture on 5 paddocks. The plantain content of each paddock is assessed in early April and was as follows:
Paddock |
Area (ha) |
Plantain content |
A |
3.5 |
5% |
B |
4.1 |
25% |
C |
3.3 |
20% |
D |
5.2 |
35% |
E |
4.5 |
30% |
Total area |
20.6 |
Weighted average 24% |
The weighted average plantain content to be entered in Overseer is 24% for this block of five paddocks:
[(3.5 x 5) + (4.1 x 25) + (3.3 x 20) + (5.2 x 35) + (4.5 x 30)] divided by 20.6 = 24%
Example 2
A farm is growing a monoculture of plantain on 15% of their farm area and strip-grazes this daily with animals that otherwise graze standard ryegrass/clover pasture.
The weighted average plantain content of pasture to be entered in Overseer is 15%: In effect this is the same as Example 1: [(15 x 100) + (85 x 0)] divided by 100 = 15%.
Example 3
A farm is growing a monoculture of plantain on 15% of their farm area and strip-grazes this daily with animals that otherwise graze other paddocks that contain some plantain.
Use the method of Example 1 across the whole area.
Example 4
A farm is growing a monoculture of plantain on 15% of their farm area and uses a standard grazing regime.
Enter the area with plantain as one block with 100% plantain.
FRNL acknowledgements
The Forages for Reduced Nitrate Leaching programme combined the expertise and resources of 10 commercial monitor farms that included Ma - ori agribusinesses, three Crown Research Institutes (AgResearch, Plant & Food Research, Manaaki Whenua – Landcare Research), one university (Lincoln University), and two industry-good bodies (DairyNZ and the Foundation for Arable Research). The main funder of the programme was the Ministry of Business, Innovation and Employment (MBIE) with the six programme partners providing co-funding. For more information, go to dairynz.co.nz/FRNL