Is your farm on target for autumn grass build up?
This week, the Grass10 weekly newsletter focuses on building grass for the autumn, when to start extending the rotation, rotation length and target farm covers.
Now is the time to focus on target farm cover, extending the rotation length and grass budgeting, while continuing to walk your farm weekly.
If you are stocked at 3LU/ha or 3.5LU/ha, you should be on a 25-day rotation and have an average farm cover (AFC) of 750kg DM/ha and 770kg DM/ha, respectively.
Grass growth rates from PastureBase Ireland are staying steady, with 60kg DM/ha/day recorded on dairy farms and 52kg DM/ha/day recorded on drystock farms, so it is important to review where you are when completing a grass walk.
Based on current and predicted growth, it will be difficult to increase AFC for farms at 3.5LU/ha on the milking platform, so reduce demand by removing animals or increasing feed. For farms stocked <2.5LU/ha, there is still an opportunity to remove surplus grass this week.
In terms of extending the rotation to 30 days by September 1st, aim to increase the rotation by 2.5 days per week during August. To map your autumn build up, all farmers should create a feed budget on PastureBase Ireland. This will help to plan out your grazings and help hit the targets that you set out for your farm. Using the targets outlined in the tables below, a grass budget will help you map out how you are going to get to your target peak AFC later in September.
Table 1: When should I start to buid autumn grass?
| Stocking rate | Date |
|---|---|
| 3.5LU/ha | First week of August |
| 3LU/ha | Second week of August |
| 2.5LU/ha | Third week of August |
Table 2: Autumn grazing targets
| Date | Cover/cow (kg DM) | AFC (kg DM/ha) | Rotation length |
|---|---|---|---|
| Stocking rate of 2.5 LU/ha | |||
| 1st August | 180 | 450 | 20 days |
| Mid-August | 200 | 500 | 25 days |
| 1st September | 300 | 750 | 30 days |
| Stocking rate of 3.0 LU/ha | |||
| 1st August | 180 | 550 | 20 days |
| Mid-August | 250 | 750 | 25 days |
| 1st September | 330 | 990 | 30 days |
| Stocking rate of 3.5 LU/ha | |||
| 1st August | 190 | 665 | 20 days |
| Mid-August | 220 | 770 | 25 days |
| 1st September | 280 | 980 | 30 days |
The autumn grazing targets are presented in the table above. This table gives farmers a target depending on their stocking rate. NB: for heavier soils, peak average farm cover (AFC) should be no more than 900-950kg DM/ha and peak grazing covers of 1,800kg DM/ha.
Identify paddocks for weed control before the end of August
With a settled few days forecast ahead and very little opportunities for week control recently due to poor weather, now is the time to assess your farm and complete any outstanding weed control. Weeds such as docks should be targeted when the plant is green (leafy) and is actively growing. Think of paddocks that you want to over sow clover into in 2024 and spray these paddocks to have a clean sward for the over sowing.
This article first appeared in the Grass10 weekly newsletter. To sign up to future newsletters, click here.
Also read: Are you the Sustainable Grassland Farmer of the Year 2023?
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