Many farmers have been using the excellent weather conditions this week for reseeding.

However, CAFRE advisers say farmers should identify underperforming swards for reseeding. A new reseed should yield in excess of 10 tonnes of dry matter per hectare per year in the first few years, and if managed correctly, maintain quality above 12 ME and 20 per cent crude protein.

Getting the establishment conditions correct is vital for effective reseeding. Soil pH needs to be between 6 and 6.5 with phosphate and potash at index 2.

Use soil analysis to determine the correct lime and fertiliser requirements. Much of the additional yield and quality from a reseed is driven by an improved response to applied nutrients.

Sow grass varieties with similar heading dates which are suitable for the intended use and ensure mixes contain a maximum of four grass varieties.

Minimal cultivation and stitching-in techniques can be used to establish new or renovate existing swards.

Minimal cultivation: If the old sward contains scutch grass or is heavily infested with docks, it should be burnt off before cultivation.

Following hard grazing (3-5cm) or silage cutting, spray off the regrowth.

About a week later (follow specific product recommendation), drill the seed into a shallow tilth prepared by harrowing the surface and roll afterwards.

Stitching in: Use this technique to improve swards with a significant proportion of perennial ryegrass. It is particularly suitable for open silage swards or stony ground.

Most drills will sow grass seed into existing swards. Minimise competition from the existing sward by hard grazing or mowing for silage immediately before reseeding.

Graze with light stock after reseeding to keep the existing sward from overwhelming the new seedlings.

Inspect all reseeds for signs of pest damage, particularly frit fly and leatherjackets.

Typically, for every kilogramme of nitrogen applied (from bag/slurry), there will be a 25 kg DM response from a young vigorous sward at peak growing time.

With this level of response, grass is cheap forage, especially when establishment costs are only likely to be incurred in the first of the potential five to ten years that the sward is down.

It is reasonable to expect to reseed between 10 and 20 per cent of the farm each year to achieve full grass growth potential.

Seeding rate for autumn reseeds normally require a higher rate of at least 14 kg of grass seed plus 1 kg of clover per acre.

Early reseeds during spring and summer can get away with a lower rate due to more “perfect” conditions.

A full reseed also allows you to reassess water troughs locations in fields and reposition them to more practical locations for paddock systems.

If weather conditions are less favourable this month, stitching in grass seed is an option but only if perennial ryegrass still makes up at least 50 per cent of the grass species (below 50 per cent, a full plough reseed is advised).

Stitching is less weather dependent and a quicker way to carry out grassland rejuvenation. If carrying out this option, always apply lime as a remedy to the increased acidification of the seedbed from the old sward dying and decaying which can impact germination of new grass seed.