This is the fourth in a series of four articles on pasture renovation by Dr Deric Charlton.
Managing the new pasture
- Encourage young grass plants to tiller and form new shoots from the plant base.
- Check for pest and slug attack - even at night in wet weather, when slugs feed!
- Try pulling young plants 1 cm above ground. If they come out, delay the first grazing.
- Light grazing with sheep or calves is best.
- Graze when the pasture is dry - avoids treading damage.
- Watch out for yellowing in the new pasture, denoting nitrogen shortage.
- Prevent weed invasion - you can spray emerging weeds.
Why do new pastures fail?
- The sown seed never penetrated the soil surface.
- The soil was too wet when cultivating.
- The seedbed was too course or too fine.
- New pasture grazed too early - try the pulling test.
- New pasture grazed too late.
- Pasture was grazed when it was too wet and was pugged.
- Seed rate was too high - emerging plants were too weak to compete.
- The seed was sown too deep - failed to emerge.
- Poor fertiliser use - not based on soil tests.
- The pests and slugs were not noticed or killed.
- Nothing done to improve poor drainage.
- Poor quality seed was used.
Seeds mixtures - what should I sow?
- Get the right information before sowing!
- Read your farming press and check farming websites.
- Discuss your needs with a local consultant or seed retailer.
- Make sure you sow the species, types and varieties (cultivars) that suit your farm.
- The New Zealand Grassland Association sells a pocket guidebook for $10.
- Livestock also enjoy a varied diet! Sow one grass (or maybe a perennial ryegrass and a hybrid ryegrass together), two white clover types, and maybe red clover, chicory or plantain.
- Check the P (purity) and G (germination) certificate that must be available with the seeds mixture.
- Ensure that weed content, if any, is very low - one year’s seeding means seven years weeding!
- Ensure seed germination level is high (over 80%).
How much to sow?
- Enough to spread about 400 legume seeds and 1,000 grass seeds per square metre.
- In practice, this is usually around 20-25 kg/ha in total, with about 10-20 kg/ha grass and 3-6 kg/ha clovers.
- A recent cost-benefit analysis, undertaken on sheep and deer systems in southern South Island, costed pasture renewal at $400/ha for direct drilling
- Full cultivation was costed at up to $550/ha.
- Benefits were assumed to peak at 2-4 years after sowing and last 10 years.
Sheep farm productivity increased by 132% and deer farm production by 60 %. Net income increased by around $400/ha (sheep) and almost $200/ha (deer). Adding chicory increased the advantage to $500/ha for sheep and $300/ha for deer farms.