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Diverse forage crops for sustainable livestock wintering

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The research

Farmers in SW England are trialling a diverse (16 variety) mix forage crop against their current systems of monoculture winter brassicas used for grazing outwintering livestock. Supported by FWAG, they will measure changes in soil health, biodiversity and monitor forage quality and yield.

This field lab has formed because the farmers were dissatisfied with the current system of monoculture winter brassicas used for grazing outwintering livestock, which damages soil health, water and the wider environment despite the low cost and reliability of the system.  This field lab aims to enable farmers to take a whole farm approach to winter feed provision.

The benefits

A diverse fodder mix can:

  • Improve soil health and biodiversity by creating habitats for organisms above and below ground.
  • Provide year-round ground cover to protect the soil from run off in heavy rain.
  • Create a source of suitable nutrition for outwintering animals and reduce the need to supplement their diet with sources of fibre like hay, creating a substantial cost saving.
  • Reduce the need for artificial nitrogen inputs by encouraging plants that fix nutrients into the soil.

Trial Design

The field lab will establish trials on 4 farms which will compare a diverse forage mixture with the farm’s “normal” mono-crop forage brassica / fodder beet. Animals will be introduced at a suitable time and stocking rate for appropriate management of the crop.

The following parameters will be measured to assess the differences and data collected for analysis:

How suitable plant species and diverse varieties are for winter grazing in terms of:

  • Maintain green leaf area and ground cover (year-round).
  • Provide suitable nutrition to animals for rumination and to maintain or increase DLWG (compared to current options)

Measuring change in soil structure:

  • Differences in water infiltration rates
  • VESS
  • Assess surface run-off
  • Measure cultivation required (for following crop)

Farm economics / cost reduction (compared to traditional wintering systems) by:

  • Differences in use of artificial nitrogen (for forage crop &/or following crop/ley)
  • Differences in cultivation effort (establishment, maintenance and following crop/ley establishment)
  • Differences in use of synthetic chemicals (g/active)
  • Farmers to weigh animals and condition score breeding animals prior and post removal from crop

Biodiversity Outcomes:

  • Monitoring of biodiversity above and below ground (worms, birds & insects)


Species selected and purpose



Functional Group


White Clover



Low growing, high protein content, minerals, digestibility, persistence, waterlogging tolerance, good relative yield

Berseem Clover



Annual, fast growing, large biomass, least hardy, soil fertility

Crimson Closer



Annual, soil fertility

Alsike Clover



Perennial, slower growing than red clover, Good for heavy and acid soils, frost tolerant

Hairy Vetch



Out competes weeds, fixes N, improves soil structure




Annual, bird feed, improves soil structure

Forage Rape



Palatable, high yield, protein rich

Kale Seed R/C



Highest yielding brassica, winter hardy, high protein

Kale x Rape Hybrid R/C



Quick establishment, winter hardy, high protein

Attila Diploid Italian Ryegrass



Short lived, high yielding,

Spadona Perennial Chicory



Protein, Minerals, digestibility, good yield, anthelmintic, drought and frost tolerance

Ribwort Plantain



Protein, Minerals, good relative yield, anthelmintic, waterlogging tolerance, marginal soil, drought

C2 Canyon Spring Oats



Soil improving, can be allelopathic, grows on less fertile soils

Daikon Tillage Radish



Deep rooted, improves soil structure, competes with weeds

Iregi Sunflower Seed



Strong roots break up compacted soils, seeds for farmland birds

White Millet Seed



Bird seed


Functional Groups

% Composition

















Grand Total


Latest updates

This is the composition of the diverse winter forage crop:

  • White clover 0.8
  • Berseem clover 0.32
  • Crimson clover 0.28
  • Alsike clover 0.28
  • Hairy vetch 4.5
  • Linseed 1.48
  • Fodder rape 0.6
  • Kale 0.525
  • Hybrid forage rape 0.12
  • Italian ryegrass - Diploid 7.2
  • Chicory 0.1
  • Plantain 0.2
  • Spring oats 8
  • Daikon radish 1.6
  • Sunflower 1.75
  • Millet 0.24

    Total 27.275 Kg/ha

There are some interesting observations on soil structure from one of the farms where a single 8 ha field was used, with a 4 ha x 16 species mix on one side and 4 ha kale on the other. The field has had exactly the same tillage and is on the same soil type. Both sides are doing very well, despite the slow start due to the dry weather.

The most interesting difference was in the soil structure on either side of the field. The diverse mix has beautiful aggregation and was friable and crumbly, the ideal chocolate cake texture. On the kale side the soil was noticeably more compact with obvious layering. Beneath the vigorous top growth you can clearly see bare ground.

Another interesting observation was that this field had a dock problem. Dock persisting on the kale monocrop side, but no sign of docks within the diverse mix.

Pollinators were prolific on the multispecies mix, but cabbage whites prolific across both trial and control.

No doubt the change in soil structure is down to root density and diversity allowing different functional groups to fulfil niche roles. The quantity of total root mass in the soil is far greater in the diverse mix .

We will monitor throughout winter grazing to see how the soil fares on each side, and most importantly animal performance and welfare. It will be interesting to see if one mob decides the 'grass looks greener' on the other side of the electric fence!

  • The earliest planted kale was hardest hit by flea beetle; this does not seem to have been much of an issue in the multispecies mix.
  • The multispecies mix appears to reduce flea beetle impacts.
  • Bolting has been an issue for one farm due to later drilling and very dry and hot weather. Long term impacts of this to be explored. 
  • Concern raised over smaller and slower establishing species such as clover and vetch being shaded out by the faster growing species. 
  • This may be due to the dry weather and poor establishment conditions. 
  • Driest farm has had very low establishment of grasses despite comprising over 50% of the mix.
  • Early insect observations showed ladybirds, butterflies and bumblebees were prolific in the multispecies mix.  Insect species preferred the multispecies mix as it matured.  
  • Good rhizosheath formation was observed on the multispecies mix, even when seedlings were small (less than 10cm above ground), demonstrating early symbiosis between microbes and plant roots. 
  • In some of the control plots there has been regrowth from previous mixes, so the results will not be 100% monocrop vs multispecies mix. However, this would have been business as usual on these fields anyway, and a comparison with the multi species mix is both valid and useful.

At the end of May soil samples were taken from each trial plot which were sent off for a comprehensive chemical, physical and biological overview. The results came back in June and showed that while the microbial biomass was average-good, the microbial activity was less than 1 on a few farms, showing microbial dormancy.

Two of the farms had the same pH but their organic matter (OM) content varied from 3.4% to 9.6%.  The farm with the higher microbial activity had the higher levels of OM which indicates the importance of OM for better microbial activity.


  • The plots were drilled between 7th May and 20th June 2022. 
  • No seed treatment was used.
  • Cultivation and drilling methods varied but included subsoiling, discing, ploughing, powerharrow, drilling and rolling.

Unfortunately the extreme dry weather hindered establishment on the sandier soils that received low rainfall, particularly where drilling was towards the end of May. Farmers have reported that the control is struggling more than the multi species mix.  This may be due to a later drilling date for the control.  The earliest drilled crop on the heavier soils near Exmoor have established particularly well.  The first species to get away were the sunflowers and radish, and the radish took the brunt of the flea beetle impacts.  The smaller seed species such as clover and vetch, struggled to get away in the dry weather.  No amount of planning can predict the weather for a field trial! One farmer has put in the same mix a month later and had far better establishment on the later planted section after a bit of rain.

Baseline soil tests

May 2022

Sowing of diverse forage crops & control (monoculture)

25th May 2022

Monitoring establishment

July 2022

Yield assessments; initial graze

31st August 2022

Bird counts, monitoring of recovery post-graze

15th October 2022

Yield assessments & grazing of trial and control

15th November 2022

Grazing & VESS

1st December 2022

Yield assessment; regraze of spring diverse forage crops; soil tests

1st May 2023

Group Coordinator

A portrait of Sarah Whaley.
Sarah Whaley

FWAG South West

South West

Sarah has a diverse range of experience having worked in the UK, Africa and Australia. She has worked with farmers to bring new enterprises on farm in Africa, ranging from building a brassica seedling nursery to developing avocado projects with partners in Israel, and development of a cassava for bio-ethanol programme. Since achieving her Masters degree in 2014 her focus has been on improving environmental, economic and social outcomes through regenerative agriculture with a focus on whole systems thinking and the circular economy.


A portrait of Tom Armitage.
Tom Armitage

Lower Brown Farm


A silhouette of an unidentifiable person.
George Greed

Fortescue Farm

Thorverton, near Exeter

A portrait of Richard Stanbury.
Richard Stanbury

Weston Farm

East Knowstone, Devon

A silhouette of an unidentifiable person.
Chris Berry

High Thornton Farm

Kenn, near Exeter

The full results from the four trials and bird surveys can be downloaded below.

The farmers agree that the following objectives were achieved through increasing diversity:

  1. Improvements in soil structure and aggregation
  2. Increases in soil organisms, and improvement in soil cycling of OM (evidence of fungal activity)
  3. Increases in biodiversity, including pollinators, insects and birds
  4. Reduction in poaching and better water infiltration
  5. Faster transition for the mobs onto the diverse mix
  6. Better dung scores consistently across the diverse mix

The following improvements and further research are required:

  1. Tweaking to ensure more winter hardy species are included
  2. Timing of grazing and stocking density need to be improved to encourage recovery and regrowth
  3. It is important to time the grazing to maximise forage value
  4. Different stock classes performed better on the diverse mix, and this needs further investigation
  5. Further research required to assess compensatory growth when stock are moved off both kale and the diverse mix.