SIMPLE GUIDE FOR OVERSEEDING PASTURES
Overseeding is an effective solution to improve old pastures; it increases yield and quality of the forage.
1. SOIL TEST at least 6 months before. Check pH is 6-6.2 and P&K indices are 2- or above.
2. CHECK COMPACTION using a spade chop a square in the grass about 30cm deep. On one side of the square put the spade in and prise out the full sod. If the grass roots aren’t penetrating down further than 10cm then you’ve got compaction. Another sign is if the soil is bone dry 7-15cm down. Address this if compaction is over 10cm. On clay soil; sward lift or mole plough. On lighter land just sward lift.
3.WEED GRASSES if they make up more than 30% of the sward, harrow them hard to remove them. With a sward of more than 70% weed grasses the best option is to reseed the sward.
4. CONTROL PERENNIAL WEEDS before seeding with a selective herbicide.
5. TIGHT GRAZE with sheep or cut. Afterwards, scarify using a spring tine harrow to open the sward up. This removes dead thatch and shallow rooted weed grasses. Ensure the tines work the top 1cm to create a tilth. Do not spread slurry or fertilize before overseeding.
6. ROLL the sward to ensure good seed/soil contact to conserve moisture. Good seed bed consolidation not only helps germination but this will also reduce the movement of leatherjackets within the soil.
7. CONTROL WEEDS after 4-6 weeks of sowing.
8. GRAZE LIGHTLY when the seedlings are 10cm high and continue at frequent intervals until the plants are well established.