You are viewing 1 of your 2 free articles

You’ll need to join us by becoming a member to gain more access.
Already a Member?

Login Join us now

Reseeding can reap rewards


Reseeding grass swards can be easily justified, even when the pressure is on dairy inputs, according to NIAB data.

Twitter Facebook

Reseeding grass swards can be easily justified, even when the pressure is on dairy inputs, according to NIAB data.


The data demonstrates grass sward is at its most productive in year one, then will lose energy value in each subsequent year. The decrease in dry matter yield and energy of a five-year-old medium-term ley could yield 48,000 MJ/ha less energy than the same mixture in its first year. Meeting this energy shortfall has significant cost implications (see table).


Limagrain’s John Spence says:“Based on these figures, more than four tonnes of feed wheat would need to be fed to make up the energy deficit in year five alone, with a price tag of about £480/ha.”


“It is estimated the cost of a full reseed is around £450-£500/ha, taking into account cultivations, seed, fertiliser, labour and machinery costs. So it will pay to reseed a five-year-old ley and reap the benefit of more productive grassland.”

Dan nattle

Dan Nattle says regular reseeding helps meet production goals

Colin Dyer

Colin Dyer reseeds 8.5ha (21 acres) of grassland every year

One dairy producer, who has no doubt reseeding pays off and it is a job which must be done properly, is Colin Dyer, Bodmin, Cornwall.


He reseeds 8.5ha (21 acres) of grassland every year for grazing, plus 25-28 hectares (60-70 acres) of silage ground, some of which is in a three-year rotation with his arable land.


“We can sometimes get four years out of our grass leys but generally it is three,” he says, admitting it is an expensive job that he would not do if it did not pay for itself.


“You can see the quantity and quality of rye-grass in a sward drop after a couple of years, it is very visible. The value of a new sward always out-performs an older sward.”

Grass ley comparison

Grass ley comparison

A ten year old ley

Grass ley comparison

A one year old grass ley

It is expected a new ley should have a high rye-grass content, usually more than 90 per cent on UK farms. By four years old, this could have dropped to 60 per cent and by eight years, this could be only 40 per cent. The rest might be the less productive meadow grasses and weeds such as docks and chickweed, says Mr Spence.


Mr Dyer relies on high quality grass for grazing and conserving for his 270-cow Jersey herd which averages 5,200 litres at 5.85 per cent fat and 4 per cent protein. “It ’s a big part of our feed so we want good grass for grazing and for four cuts of silage. Turnout is mid-May onto first cut silage aftermath and the cows graze swards on a rotation, so if a field of grass does not keep up, it really messes up the system.”


He believes grass has to be treated like a cereal crop with the nutrients it requires at the right time. “If you do not treat it properly, it won’t grow properly."


For silage leys he is using Highmax, a high sugar hybrid rye-grass tetraploid which gives early spring growth and fast regrowth, making it suitable for multiple silage cuts with aftermath grazing.


The grazing leys are sown with Maxigraze, a high sugar mixture with white clover, which Mr Dyer says feeds well and, being drought resistant, suits his farm.


Dan Nattle, Lanivet, near Bodmin, grazes his spring-calving British Friesian herd from February to November. He says he needs productive grassland for this extended season and admits having expanded the herd to 210 cows this year, he will not be reseeding quite as much of his 93-ha (230-acre) farm as he would ideally like to.


“I aim to keep swards for five years and reseed 16ha (40 acres) every year. This year I will have to ‘nurse’ some grassland and keep the nutrition right. Hopefully we will avoid too big a dip in productivity.


“We want to maintain our 5,000-litre average on our low cost system and our milk contract is putting more emphasis on milk quality and a regular reseeding programme plays a big part in meeting our production goals.


Mr Spence says: "The most successful reseeds are planned and managed properly. It costs the same to do a bad reseed as a good reseed so it is worth discussing the site and its needs. I strongly recommend field inspections and keeping field records.


“These will show which fields perform better than others and, with the grower’s knowledge and consideration of soil type and location, a reseed programme can be prioritised. It is not always the oldest sward which needs reseeding first.”


Soil pH, nutrient levels or compaction problems must be resolved prior to reseeding. Seedbeds should have a fine tilth and ideally need to be rolled before and after drilling to a depth of no more than 15mm.


“Pest control is important too,” says Mr Spence. “Populations of pests, such as leatherjackets, will be reduced by tank mixing an insecticide with glyphosate when spraying off the old ley, but careful monitoring for signs of damage during establishment will still be necessary.”


Choice of seed mixture is vital and this depends on its use – grazing, by sheep or cattle, cutting or a combination of both. “Growers should take advantage of new mixtures which offer agronomic and feed value benefits," says Mr Spence.



**Typical feeding value and yield of a medium-term cutting ley (NIAB data) and cost to replace the LSOT energy with feed wheat of 13.7ME, 86% DM and £120/t


Sward age (years) Yield (kg/ha) Average ME Lost energy (MJ/ha)

Cost to replace with feed wheat (£)

One 14, 300 11.5 - -
Two 13, 800 11.3 8, 510 86
Three 13, 100 11.2 17, 730 179
Four 12, 100 11 31, 350 317
Five 10, 900 10.7 47, 820 484
Six 9, 600 10.5 63, 650 644
Seven 7, 900 10.4 82, 290 832
Eight 6, 700 10.3 95, 440 965
Twitter Facebook
Rating (0 vote/s)
Post a Comment
To see comments and join in the conversation please log in.
FG Insight and FGInsight.com are trademarks of Briefing Media Ltd.
Farmers Guardian and FarmersGuardian.com are trademarks of Farmers Guardian Ltd, a subsidiary of Briefing Media Ltd.
All material published on FGInsight.com and FarmersGuardian.com is copyrighted © 2016 by Briefing Media Limited. All rights reserved.
RSS news feeds