A landmark international study, led by Trinity College Dublin, reveals that increasing plant diversity in agricultural grasslands is a key strategy for boosting yields while significantly reducing reliance on nitrogen fertiliser.
The research, published in the journal Science, outlines the findings of the "LegacyNet" common experiment conducted across 26 international sites.
Key Findings and Benefits:
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Optimal Diversity = Higher Yields: The study showed that multispecies mixtures—specifically a blend of two grasses, two legumes, and two herbs sown in approximately equal proportions—outperform conventional, low-diversity practices.
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Yield Data: The six-species mixture produced an average of 12.3 tonnes per hectare per season. This represents an 11% increase in yield compared to a grass monoculture that required more than double the amount of nitrogen fertiliser.
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Nitrogen Reduction: The high performance is attributed to synergistic interactions (stronger than the sum of the parts), particularly between grasses, legumes, and herbs, allowing the system to use far less synthetic nitrogen.
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Climate Resilience: The yield benefits of these diverse grasslands were found to increase further under warmer temperatures, highlighting their potential as a critical tool for climate adaptation in sustainable agriculture.
Lead author Professor Caroline Brophy summarises the results as a “win-win-win,” driving more environmentally sustainable forage production, improving yields, and enhancing adaptation to a warming climate.
Original Article can be read on the Trinity website: Increasing plant diversity in agricultural grasslands boosts yields, reducing reliance on fertiliser