Grass return on investment: The value of your grass

Farmers seeking productivity from their grassland, whether increased yields, fewer inputs or increased biodiversity and soil health, need to know how to make the most of this sustainable, beneficial crop.


Good quality grazed grassland is the cheapest feed for your livestock and is the base upon which profitable farming is built. Over 70% of utilisable agricultural land in the UK is grassland, with nearly 57% given over as permanent pasture. The UK has the ideal climate for growing grass. Ryegrass grows best at between 5°C to 25°C – and most of the UK is between these temperatures 95% of the time. Like all crops, growing grass requires careful management to maximise yields and utilisation.


The value of your grass - Grow your future with grass

There is no mystery in the benefits of well-managed grassland; providing a source of quality nutrient-rich forage, increased farm biodiversity, increased soil health, the potential for reduced inputs, and one of the most sustainable cost-effective feed for livestock farmers – effectively providing ‘free litres and weight’ – while supporting animal health and maintaining overall farm productivity. Good quality grassland is the cheapest feed for your livestock and is the base upon which profitable farming is built. 


High performing grassland, at maximum productivity, delivers more energy resulting in more weight gain and higher milk yields. Maintaining your grassland at maximum productivity (GI5), by reseeding or overseeding poor performing fields, will make your grassland your most productive asset. Increasing the productivity of your grassland from a GI3 to a GI5 you could increase your grassland productivity to over £17,449 per ha.


Find out more about our Grassland Index Guide & Grassland Management Guide 


We calculate the value of a poor performing field, the cost of reseeding it and work out the value of the return on investment for beef, dairy, lamb and grass yield. Find out more below...  Sustain your farm’s resilience by maximising quality homegrown forage.

Grass | return on investment

The value of grass reseeding


shown by Grass Yield

Based on a GI5 field (>80% sown productive species)

1st year perennial ryegrass grass field (two cuts & graze) = yield of 15t DM/ha

Value of 1st year re-seed (two cuts & graze) = £2,100.00/ha*


Based on a GI3 field (only 50% sown species left)
An older or damaged sward with 50% perennial ryegrass may yield the following = yield of 7t DM/ha

Value of this field (two cuts & graze) = £980/ha*


Total potential benefit of reseeding you GI3 field to reach GI5 = an increase in over £1,120/ha, from £980/ha > £2,100.00/ha

*DM Value of £140/ton 



shown by production 

Based on a GI5 field - autumn sowing of Intermediate and Late PRG mixture with two cuts & graze.

  • Potential Grass yields = 15t DM/ha*1
  • Potential ME yield = 187,420 MJ*1

Production value of this field;

  • 35,362 litre of milk worth 40p/l= > £14,144  / (28.51p/l (10 year average) *2 = > £10,081)
  • 3987kg lamb worth 437.65p/kg *2 = >£17,449
  • 3987kg beef worth 351.55p/kg *2 = >£14,016


Based on a GI3 field (only 50% sown species left)

An older or damaged sward with 50% sown species may yield the following:

  • Potential Grass yield = 7t DM/ha
  • Potential ME yield = 86,400 MJ

Production value of this field;

      19,060 litre of milk worth 40p/l = £7,624

  • 1838 kg of lamb worth 437.65p/kg *2 = £8,044

  • 1838 kg of beef worth 351.55p/kg *2 = £6,461


Total potential benefit of reseeding you GI3 field to reach GI5:

  • An increase in over 16,302 litres of milk worth over £6,520, from £7,624 to > £14,144
  • An increase in over 2149 kg of lamb worth over £9,405, from £8,044 >£17,449

  • An increase in over  2149 kg of beef worth over £7,554 , from £6,461 >£14,016


Can you afford not to reseed your grassland?

*40p/l actual price

*1 Data taken from the Recommended Grass and Clover List 2022/2023

*2 Prices are AHDB industry figures for the 10 year average price (2012-2021) for meat and milk

5.3mj/lite of milk, 47mj/kg meat

Grass | The cost of reseeding

What are your costs for reseeding? 


This is an overview of the typical costs associated with reseeding and overseeding. Costs are based on The National Association of Agricultural Contractors 2022/2023 rates. If carrying out the work yourself these costs would be reduced. 


Cost of reseeding (ha)

Soil sample £25.00
Lime (2.5t/ha) £95.00
5l/ha Glyphosate £52.50
Spraying costs x2 £33.00
Ploughing £75.00
Rotovating £88.00
Rolling x4 £104.00
Fertiliser 250kg/ha 8.20.30  £189.00
Fertiliser application £15.00
Grass drilling (with harrow) £48.00
Grass Seed (perennial + clover)


Post emergence spray £35.00
Total Cost £919.50



Cost of overseeding (ha)

Soil sample £25.00
Lime/Fert/Spray as needed £95.00/ha
Harrow £34.00/ha
Grass drilling £34.00/ha
Grass Seed £75.00/ha 
Total Cost £263



Now compare these costs with the above financial return available in the first year....


Grass | The Cost of Doing Nothing

Another way to look at the numbers is to assess the amount of dry matter produced.


A field that is 50% ryegrass and 50% weed grasses will not be as productive as a young sward, as over the years weeds will become more prominent.

The graph below shows that just one year after reseeding, weed species can make up to 18% of a sward. After four years, that figure has more than doubled to 38% and, after eight years, weeds will be starting to dominate the sward (51%).

On average, an eight-year old field will typically yield around 5.5T DM/ha compared with a new field, which could produce around 15T DM/ha - meaning you could be missing out on three times as much grass.



Good Grass Guide

Read our Grassland Management Guide, and order your free copy, for our top tips and advice and detailed GI (Grassland Index Guide) on how to index, manage and maintain your grassland to maximise productivity, helping to sustain your farm’s resilience by maximising quality homegrown forage. Find out more here.