Topping a paddock primarily involves mowing the pasture to a specific height, following the rule of thirds to ensure healthy regrowth and pasture management.
Understanding Paddock Topping
Topping is a pasture management practice where grass is mowed down to a certain height. This helps control weeds, encourages fresh growth, and can improve pasture quality by preventing grasses from becoming too coarse and seeding out. The key is to remove the top portion of the plant without stressing it too much.
The Rule of Thirds for Topping
According to best practices for topping paddocks, you should adhere to the rule of thirds. This simple rule is crucial for maintaining pasture health and vigour.
The rule states: don't mow more than 1/3 of the plant height.
This means you should leave at least 2/3 of the plant's height intact. Mowing too low can stress the plant, reduce root reserves, and slow down regrowth.
Applying the Rule of Thirds
The mowing height is determined by the current height of your pasture grass. You should aim to remove no more than one-third of the standing biomass.
Here are examples based on the rule:
| Current Pasture Height | Maximum Height to Mow Off (1/3) | Recommended Mowing Height (Leave 2/3) |
|---|---|---|
| Approx 120mm | 40mm | 80mm |
| Approx 180mm | 60mm | 120mm |
Note: Heights are approximate and depend on pasture species and conditions.
Managing Taller Pasture
If your pasture is particularly tall, like approximately 180mm, mowing down to the ideal residual height (around 80mm) in one pass might violate the rule of thirds (removing 100mm from 180mm is more than 1/3).
In such cases, you may need to mow in stages:
- First Pass: Mow at a higher height, such as 120mm (removing 60mm, which is 1/3 of 180mm).
- Second Pass (if needed): Once the pasture has regrown slightly or if conditions allow, you can make a second pass at a lower height, like 80mm, to achieve the desired base height, ensuring you still don't remove more than 1/3 of the plant's current height in the second pass. This staged approach helps prevent shock to the plants.
By following the rule of thirds, you promote healthy pasture growth, reduce stress on the sward, and improve the overall quality and productivity of your paddock.
