Managing know-how wins
SUCCESSFUL grass establishment depends on management of a high order, from varietal choice through to seeding year husbandry.
That is evident from visiting the farm of north Devon producer Ranald Fowler, who is chairman of south-west based co-operative Mole Valley Farmers.
He farms 214ha (530 acres) at Boode Farm, Braunton, Devon, in partnership with his son Gavin.
Half the farm is down to grass, the rest is in winter barley grown for seed or winter wheat for the dairy ration.
All used to be grown in a straightforward crop rotation of four years cereals and two years grass – in addition to the permanent pasture on the steeper land. Set-aside complicated management until the flexible option was introduced. Now 15% of the arable area is set-aside for two years after cereals. Grass cover allows grazing from Sept 15 to Jan 15, and with no fertiliser applied provides a clover rich grass sward.
Ranald Fowler sows most of his 24ha (60 acres) of grass reseeds in the autumn. Winter barley provides an early start to reseeding. "Re-seeding after the winter barley gives us the chance to sow in the first fortnight of August and gives a denser, more established sward to start grazing in spring."
The grass mixture is based on late perennial rye grasses, with 5% white clover. Tetraploid varieties and Timothy are added to the mix to boost all-important palatability. Mr Fowler used to include earlier perennial ryegrass varieties in the sward, as well as Italian. These produced an excellent first cut, but went stemmy in mid and late season and left an open sward. This was a disadvantage, especially on the light, sandy soil.
Establishment is the conventional one of broadcasting by using an old-fashioned Thomas grass seed box. Mr Fowler favours the "surface seeding" technique this machine gives because it scatters the seed evenly over the ground.
Grass seed is sown into a fine, firm seed-bed and chain harrows trailed behind the seed box work the seed into the surface of the soil before a final press with the Cambridge roller.
Soil samples of the seeded area are tested every three to five years to check pH, phosphorus and magnesium levels. Ground limestone is applied to maintain soil at a pH of 6, which is preferred by grass.
Key nutrients for grass and clover seedlings, phosphorus and potash, are applied at a rate of 75kg/ha (60 units/acre). Nitrogen is excluded at this stage to ensure a strong take of clover, says Gavin Fowler.
The developing sward is grazed tightly with sheep in the autumn to encourage tillering and help consolidate the light, dry soil. The added advantage of light sheep grazing is that it helps reduce weeds. Those that do grow are taken out with a clover-safe herbicide.
In the first year after sowing the new ley is cut for silage twice and then grazed. Sow outs on set-aside land are mown to provide green cover until Sept 15, when the clover-rich grass can be grazed or conserved.
In contrast, clover has almost disappeared from the permanent pasture on the steeper land, which is grazed by the cows.
"The older varieties will not thrive under the high nitrogen conditions required for conservation and grazing," says Mr Fowler.
He intends to renovate 8ha (20 acres) of permanent pasture on soil too shallow to plough on a regular basis.
"Existing pasture will be grazed severely and a grass and nitrogen tolerant clover seed mix broadcast over the top," he says. Hard grazing after sowing will reduce competition from the old sward and help to tread in the seed.
• Seed-bed should be fine and firm.
• Check soil pH and phosphorus status.
• Direct sowing gives best results.
• Graze in autumn to encourage tillering.
Left:Devon milk producer Ranald Fowler seeks a clover-rich grass sward. Right: Gavin Fowler favours the "surface seeding" technique provided by this Thomas grass seed box that scatters seed evenly over the ground.