Assessing Plantain
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Plantain in pastures can reduce nitrate leaching by affecting nitrogen in urine and soil retention. The page teaches you the importance of assessing the proportion of plantain in your pasture. You might need to show evidence of its effect on nitrate leaching to regional councils in some areas. It's best to assess close to grazing time, especially in Autumn when pastures grow actively. Use a visual method to estimate plantain percentages. Walk across paddocks, identify plantain amounts, and record them. There are images to guide you on what different percentages look like. Finally, you can calculate the average plantain content across your farm. There's also an Excel template provided for recording.
Plantain can reduce nitrate leaching by reducing the amount and concentration of nitrogen in urine, and by retaining more nitrogen in the soil. The effectiveness of plantain pastures for reducing nitrate leaching depends on the proportion (%) of plantain relative to other species in the pasture.
The following is a guide to assessing the proportion of plantain in a pasture sward.
Why assess the proportion of plantain?
In some regions, farmers, rural professionals or environmental auditors will need to supply evidence (e.g., OverseerFM report) to their regional council to show the effect plantain could be having on their nitrate leaching.
OverseerFM can adjust the proportion of N in urine and the urine patch N load by predicting the amount consumed by ruminants when the average proportion (%) of plantain in the pasture is input into the model.
When to assess
- As close to grazing as possible, no longer than 7 days before grazing
- The whole block may need to be conducted over several weeks to cover the whole area
- In Autumn when pasture is actively growing
Plantain visual assessment recording template
This simple Excel template below can be used to keep a record of visual assessments conducted on-farm.
How to assess plantain in pasture
Our visual assessment method can be used to estimate the proportion of plantain in the pastures. The method has been tested across New Zealand and has been shown to be accurate against pasture composition cuts to within a 10% confidence interval. Get a feel for what each plantain percentage looks like using the galleries below.
Out in the paddock
- Identify or establish blocks (group of paddocks) as you would in Overseer
- Walk diagonally across each paddock in the block
- Visually estimate the % of plantain available to graze in each paddock - 5% increments up to 30% then 10% up to 60%
- Record the % of plantain in each paddock
What 5% - 30% plantain could look like
5%
1 / 9 images
5%
2 / 9 images
10%
3 / 9 images
10%
4 / 9 images
15%
5 / 9 images
20%
6 / 9 images
25%
7 / 9 images
30%
8 / 9 images
30%
9 / 9 images
What 40% - 90% plantain could look like
40%
1 / 6 images
50%
2 / 6 images
60%
3 / 6 images
60%
4 / 6 images
70%
5 / 6 images
90%
6 / 6 images
Calculating average plantain (%) across the farm or block
- List all the paddocks, their areas and the percentage of plantain in each one.
- Mulitiply the area of each paddock (A) x plantain percentage (B) to give C.
- Calculate totals for A and C to give D and E.
- The average plantain content is E divided by D.
In the example below, average plantain content is 506.5/20.6 = 24.6%
| Paddocks | A) Area (ha) | B) Plantain content (%) | C) A x B |
| Red paddock | 3.5 | 5% | 17.5 |
| Blue paddock | 4.1 | 25% | 102.5 |
| Green paddock | 3.3 | 20% | 66 |
| Purple paddock | 5.2 | 40% | 208 |
| Yellow paddock | 4.5 | 25% | 112.5 |
| Total | 20.6 (D) | (E) 506.5 |
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