PROVEN BENEFITS
Research shows that multi-species swards can outperform simpler swards containing only one or two species. We searched the academic literature (1990 – 2019) and identified 77 studies comparing the performance of multi-species swards against a control sward of one or two species.
Performance was measured using a total of 20 factors, relating to forage quality, final product quality or yield, and environmental benefits. Results for the most common factors (used in more than 5 studies) are shown below. There were considerable gaps in the research literature, particularly in relation to the relative environmental impacts of different swards.
WHAT WE FOUND
- We found 77 experimental studies comparing a multi-species sward with a one or two species control sward.
- Studies were located across 25 countries, with 50% in the same climate zone as the UK (oceanic).
- Approximately half the studies were based on cutting regimes and, half on grazing.
- Approximately a third of studies used a perennial rye-grass and white clover control sward to compare to compare against multi-species swards.
- 68% of studies used a chicory-containing multi-species sward
- The majority of studies showed a performance advantage for the multi-species sward, notably for lamb meat quality, weed suppression, nitrogen leaching and forage quality.
- The results indicate that our understanding of multi-species swards is incomplete, in particular more research into the environmental performance and stress tolerance potential of multi-species swards is needed.
The graphics below show some of the trends we noted from the various studies for a range of different measures of the performance of diverse swards compared with simpler leys.
FORAGE
Note: Percentages do not add up to a hundred because some studies compared multiple swards
Did diverse forages have a higher Dry Matter yield than the control?
![Dry Matter feed](https://www.multispeciessward.co.uk/wp-content/uploads/2021/03/shutterstock_193937240-180x180.jpg)
Did diverse forages have a lower Neutral Detergent Fibre level than the control?
![Neutral Detergent Fiber ndf Neutral Detergent Fiber molecule over grass](https://www.multispeciessward.co.uk/wp-content/uploads/2021/03/ndf-180x180.jpg)
Did diverse forages have a higher digestibility than the control?
![dairy cow digestion dairy cow digestion](https://www.multispeciessward.co.uk/wp-content/uploads/2021/03/shutterstock_243774922-180x180.jpg)
Did diverse forages have a a higher Crude Protein level than the control?
![clover crude protein amino acid overlaid on clover](https://www.multispeciessward.co.uk/wp-content/uploads/2021/03/clover-crude-protein-180x180.png)
PRODUCT YIELDS
Did cows grazing on diverse swards produce a higher milk yield than on the control?
![dairy dairy](https://www.multispeciessward.co.uk/wp-content/uploads/2021/05/dairy-parlour-166x166.png)
Were lambs grazing on diverse swards heavier than on the control?
![sheep-248632_1920](https://www.multispeciessward.co.uk/wp-content/uploads/2021/06/sheep-248632_1920-180x180.jpg)
ENVIRONMENTAL PERFORMANCE
Were diverse swards better at suppressing weeds than the control?
![OLYMPUS DIGITAL CAMERA](https://www.multispeciessward.co.uk/wp-content/uploads/2021/05/Grebe-220620b-180x180.jpg)
Did multi-species swards have more potential for reducing nitrogen leaching than the control?
![Nitrogen leaching nitrogen leaching](https://www.multispeciessward.co.uk/wp-content/uploads/2021/03/shutterstock_625525349-180x180.jpg)
ABOUT THE STUDIES
Hover over the images to find out more about studies used for this literature review