For the Future of Farming

Reseeding offers immediate and lasting return on investment

Current reseeding rates of 2 – 3 % per year are far from the required rate if livestock farms are to maximise returns from forage.  Grass leys are on average replaced far less often than every 10 years. Even the best managed swards will suffer deterioration beyond 6 – 7 years with the ingress of weed grasses inevitable though not always obvious.

Grass re-seeding

Benefits of reseeding

Benefits of reseeding
  • Improved feed value
  • Higher dry matter intakes
  • Better response to fertiliser
  • Greater stocking densities

These all add up to make successful pasture renewal one of the most cost effective investments.

Whether used for extra milk production or additional liveweight gain, the extra productivity per acre of a new grass ley is significant running into hundreds of pounds over and above the reseeding costs. The benefits of the first year should then continue for the duration of the ley.

Other benefits

  • Grazed grass is the most cost effective way to feed livestock – Only quality grass will fulfil this claim
  • Weed grass ingress reduces productivity – 10% Docks = 10% less grass.
  • Leys may look green, but after 6 years it is likely that at least half of the plant population will be weed grasses such as fescues, bents and meadow grasses. - These will be significantly less productive in terms of dry matter yield, will have lower D – value and be less palatable to livestock. Their response to fertiliser will be lower than modern ryegrasses.
  • Variety selection is vital, choose the best varieties from the recommended list. - The differences even between the top and bottom of the recommended list can be significant. Don’t compromise and look to cut costs on variety selection.
  • What’s happening below the ground? – Compaction problems are reality this can result in stress on plants = less productivity.
  • Check for leatherjackets & Fritfly – Consider a break crop
  • Soil test – Supplies vital info. Correct before sowing
  • Full reseed or overseed. – Discuss options as cost is a major driver with farmers.
  • Seed to soil contact – Make sure sowing / overseeding is correct – Do not cut corners, - Rolling after sowing is crucial. Sowing depth should be 1 cm

Example of ‘best practice’ grass reseed

  Reseeding Actions

  Agrochemicals (spray off old sward)


  Plough up old sward 

  Seed bed preparation, including rolling


  Fertiliser (including application)



  Cost (£/acre)









A new ley containing the best performing grass varieties will produce an extra 1,000 kg of dry matter / acre in the year when compared to an 8 – 10 year old pasture. 

Further benefits are the new ryegrasses will have superior D values to the old sward that they replaced and you can expect the ME of the grass to be on average 0.8 MJ / Kg higher. Therefore we can extra 13,400 MJ / Kg of metabolisable energy per acre. In terms of milk production this is worth over 2,500 litres per year.

Typical Reseeding Benefits (Dairy)

  Original Pasture
  New Ley

Grass production (kg DM/acre)

ME content (MJ/kg DM)

Extra energy output (MJ/acre) from new ley

Stocking rate (cows/acre)

Extra milk production @ 5.3 MJ/litre (litres/acre)

Extra milk value @ 22p/litre (£/acre)

Cost of full ‘best practice’ reseed (£/acre)

First year benefit of reseeding (£/acre)