Preparing seed-bed crucial to get the most from grass re-seed
As feed costs rise, all livestock farmers need to produce more from home-grown forage, the cheapest of which is grass, says Helen Mathieu, British Seed Houses’ area sales manager.
“Producers either need to grow more or use what they have more effectively.”
As such, targeted re-seeding can help boost grassland productivity, but ensuring the seed-bed is prepared correctly is pivotal in getting grass off to a good start.
“The aim should be to produce a fine, firm and clean seed-bed that you can ride a pushbike over with ease,” she says.
“Preparing a seed-bed is also your chance to level out pasture – once grass is established you are stuck with the bed you’ve got.”
And when ground is not prepared correctly, grassland production is likely to be compromised. Bumpy areas will limit germination and encourage weeds to grow in the spaces created. When ground is in good condition, it will also be able to take stock for longer
There is the potential for more winter damage this year following the harsh season, so it’s important to walk the farm and see where re-seeding is appropriate, says Ms Mathieu.
Seven steps…
According to Ms Mathieu, and Countrywide agronomist, Simon Trenary, there are seven key steps to preparing ground for a re-seed:
1) Soil analysis and soil structure
• Analyse soils for pH, K and P
• The trick to getting the best yields is to manage grass as a crop – the best on-farm results are seen when grass is included in a crop nutrition program
• To assess soil structure, get a spade and dig a series of holes in a W shape across the field. Focus on areas where you are seeing production problems and avoid the headland – sub-soiling may be relevant when ground is compacted
• Once soils have been analysed, any imbalances can be rectified – for example when pH is too low, liming may be appropriate
2) Ditch maintenance
• Makes sure ditches are cleared
• Drainage is often forgotten when preparing fields for a re-seed – getting soil preparation right means nothing when water can’t get away
3) Weed control
• In the first week of March, go out and assess the stage of weed growth and see whether weed control is needed
• There is no point spraying fields in February as most products need the weed to be actively growing to work
• When fields have a heavy weed burden, an autumn re-seed may be more appropriate
4) Spray off grass with glyphosate
• Grass can be sprayed off as soon as it starts to grow – this is usually from March onwards
• Only spray off when you know pH is correct and P and K levels have been established
Spraying off old leys prior to re-seeding does not have to mean grass has to be lost. In fact, subject to individual product labelling, some products allow grass to be grazed or silaged after application, explains Ms Mathieu.
5) Slurry application
• Full winter slurry stores can be used very effectively in a spring re-seed as phosphorous is needed to get a grass crop growing
• Slurry testing is valuable to know the nutrient content of what you are applying
6) Cultivation
• Ground should then be ploughed
• Where appropriate, a subsoiler should follow
• Sub-soiling can be hugely beneficial, but, it can do more harm than good, so should be used on a farm-by-farm basis
Soil structure is just as important for grass as any other crop, says Mr Trenary.
“Muck spreading and ploughing can result in consolidation, so sub-soiling could be used to remove the plough pan.”
A deep plough pan is likely on silage ground, explains Ms Mathieu. However, pans from livestock usually go to root depth, so ploughing should get rid of it.
7) Rolling
• Ground should be rolled as soon as possible after ploughing – rolling firms the soil, maintains moisture levels and stops ground from drying out
• A seed-bed will need to be rolled at least twice before sowing
• Judge your own soil – be aware capping can occur on clay soils
You can encounter problems when there is a delay between ploughing and rolling, says Mr Trenary.
“When soils are ploughed and it then rains, ground will go boggy. Equally, with drier springs, leaving the ground open in dry conditions can cause soils to go like rock.”
Farm case study: Paul Candy, Pyle Farm, Frome
Producing the perfect seed-bed will improve grass germination and maximise milk yields, according to Somerset dairy farmer Paul Candy.
“There is a two to three litres a cow a day difference in milk production when cows are grazed on new leys versus older pastures,” he says.
“Grass leys may cost a lot to put in, but the potential return is huge. However seed-bed preparation is crucial.”
With the 200 cow herd yielding 9000 litres a cow a year, the farm needs to produce high-quality silage and grazing leys for when cows go out in spring and summer.
Mr Candy tries to re-seed 12-16ha (30-40ac) on the 182ha (450ac) farm every autumn and works closely with agronomist Simon Trenary to create the best possible seed-bed.
“The aim has been to treat every field the same – be it maize, corn or grass. Field condition on grass leys is just as, if not more important than arable ground because grass is re-seeded every five years.”
Despite re-seeding in autumn, Mr Candy and Mr Trenary go round the farm now to select fields for later cultivation. “You need to think about it now and look back to grass production last year. Planning now also allows grass seed to be forward bought.”
Fields selected for a re-seed are treated with glyphosate at the end of July. These fields are then grazed or mowed.
“Cutting makes ploughing a lot easier. In the past, we have also made round baled silage to feed to young stock.” Slurry or solid muck is then applied and ground ploughed.
“Whatever we plough, we always make sure we roll it on the same day. If we don’t, our soil becomes really dry.” After rolling, ground is subsoiled and then Cambridge rolled, with power harrows run over just before sowing.
“We subsoil everything we plough, apart from some fields where soils are not deep enough.
And because the ground at Pyle Farm is clay based, grazing ground can become wet, so getting drainage right is crucial and can extend the end of the grazing season by 10 days, says Mr Candy.
“By getting the seed-bed right grass silage quality has improved and we are seeing a greater response in milk yield.”