If you established a new reseed last year and want to stitch in white clover seed this year, how should you do it? Germinal grassland expert William Fleming provides his eight top tips.
Sowing white clover
Limited clover-safe sprays for controlling weeds in new leys means stitching in clover once a grass reseed is established can be attractive. This enables any existing, heavy broadleaf weed burdens to be well and truly controlled in the ley’s first year, with clover introduced in the following season.
However, all too often farmers’ good intentions to plant white clover seeds at a later date can go forgotten. Therefore, it’s vital you build this into your pasture strategy or you could be missing out on productivity gains.
After all, white clover helps build sward biodiversity, aids soil structure, increases dry matter intake and boosts performance. As a legume, its nitrogen-fixing abilities are also equivalent to 150-250kgN/ha. William recommends that you think about the following when introducing clover.
1. Ensure broadleaf weeds are under control
Make sure you have weeds well and truly under control. Work with your agronomist to ensure the correct sprays are used at the right time both before and after establishing the new ley.
2. Choose the right clover to suit management
Always choose clovers from the Recommended Grass and Clover Lists (RGCLs) and opt for a blend. If you’re wanting to cut your grass sward for dairy cows, choose large- and medium-leafed varieties. For sheep, choose small- and medium-leafed clovers.
3. Introduce white clover seed when soils are warm and moist
Stitch in clover at least six weeks after weed control to adhere to withdrawal periods. A warm, moist seedbed is vital (April-August, depending on location).
4. Ensure good seed-to-soil contact
Over-sow after grazing or cutting the field to improve the seed-to-soil contact.
Identify the pastures you want to reseed this Autumn now and put together a targeted weed control programme with your agronomist to nip weeds in the bud before establishment. Getting a good clean seedbed could mean you could include white clover in the mix from the start which will reduce the costs associated with going in at a later date.
5. Opt for a slightly higher seed rate
A slightly higher seed rate of 4kg/ha is recommended for over-sowing compared to a full pasture reseeding effort to compensate for higher seeding loss.
6. Carefully graze the grass to help white clover establish
Undergrazing or overgrazing is the enemy when it comes to clover establishment. Graze too hard and white clover will be knocked back and graze too lightly and grass will outcompete the clover. The key is to graze down to a residual of 1,500kgDM/ha or 4cm so sunlight can get down to the clover. Graze lightly and for short periods until clover is well established.
7. Adopt good rotational grazing
Once clover has established, adopt good rotational grazing to enable clover to rest and recover – always graze down to 4cm.
8. Think carefully about fertiliser
Avoid application of nitrogen in the early establishment as it will encourage grass to grow and increase the risk of clover being outcompeted. Apply a 0:20:30 fertiliser just after clover has been stitched in so potassium and phosphate are available for the young clover plant.
You can also read William's five top tips for sowing red clover.