Stick with the programme: Reseeding permanent pasture 

Yield and quality together produce the grass and forage performance you need to drive meat and milk production. While yield provides quantity, quality supports livestock digestion of metabolisable energy (ME). 

But as pastures get older, both decline, increasing the need for bought-in feed to sustain production if you don’t consider reseeding. 

Germinal expert Harley Brown-Keech explains that by looking for signs of lost grassland production, you can lift performance where it will most benefit your stock. 

What happens to yield in permanent pasture? 

Grassland becomes permanent pasture five years after a reseed, with the yields of five varieties falling by around 2 tonnes of dry matter (DM) from year five (2018) to six (2019) in the chart below. By year eight (2021), all varieties produced around 50% less yield compared to year one. 

Perennial ryegrass yields – 2014-2021 

Source: Scotland’s Rural College (SRUC)

Why is your grassland production falling?

Five years after a reseed, weeds and meadow grasses take hold, filling bare soil where swards are damaged. When there’s less perennial ryegrass, the table below shows how lost yield and metabolisable energy (ME) impact milk and meat production.

Grassland and livestock production at different perennial ryegrass levels

Source: Institute of Biological, Environmental and Rural Sciences (IBERS)

• At 70% perennial ryegrass – 9,000 litres of lost milk or 540kg of meat per hectare.
• At 50% perennial ryegrass – 15,200 litres of lost milk or 916kg of meat per hectare.

A new reseed of your lowest performing pasture can help close the ME gap, reducing costs for bought-in feed.

Can I apply more fertiliser to improve permanent pasture production?

You might be tempted to apply nitrogen to boost growth in older swards, but research by Germinal Horizon found no effect on annual meadow grass yield when increasing nitrogen (N) fertiliser from 50kg per hectare to 150kg.

The table below shows how applying fertiliser on meadow grass species in permanent pasture is less effective.

The impact of nitrogen fertiliser on grass yield – meadow grasses vs Aber HSG

Source: Germinal Horizon

While rough stalk meadow grass and Yorkshire fog responded well to N, they generated much lower yields compared to Aber High Sugar Grasses (Aber HSG). AberGain produced 17.8% higher yield than Yorkshire fog and 43.5% more than rough stalk meadow grass.

Reseeding with high-performance Aber HSG varieties can replace meadow grasses and improve yield in your permanent pasture.

What are the best practices for increasing grassland production?

An annual reseeding programme consistently increases your grass yield and quality, and supports sustainable production by reducing the environmental impact of bought-in feed.

A successful reseed produces higher-yielding, higher-quality grass to drive your livestock performance and quickly start paying for itself.

Here are Harley’s three tips to get the most out of your reseeding programme:

1. Measure grass weekly – find fields that aren’t delivering
2. Eliminate weeds – target fields with 10% coverage or more
3. Keep production high – aim to reseed 10-15% of total grassland each year

Overseeding can also make sense for your farm if:

• Costs are tight
• Restoring a patchy reseed
• Stitching in clover to an existing sward

Get expert support for your next reseed

Read our in-depth reseeding guide for further advice or if you have any questions, contact your regional Germinal expert for reseeding plans that fit your livestock system.