A groundbreaking study from the world’s longest-running ecological experiment, the Park Grass Experiment in Rothamsted, England, has revealed a dire consequence of excessive fertiliser use: it is devastating both pollinator populations and floral biodiversity. Conducted over two years, the research highlights a direct and dramatic relationship between nitrogen-based fertilisers and the decline of bees and flowers.
The study found that even moderate nitrogen fertiliser application reduces flower abundance by fivefold, while halving the population of pollinators like bees. The cascading impact of this decline affects the entire food chain, posing a threat to ecosystems and agricultural productivity.
Lead researcher Dr. Nicholas Balfour from Sussex University expressed concern about the unprecedented link between fertiliser use and pollinator decline:
“As you increase fertilisers, pollinator numbers decrease—that’s the direct link. It’s having a drastic effect on flowers and insects, with knock-on effects up the food chain.”
Conversely, plots free of chemical fertilisers showed an astounding ninefold increase in bee populations. Even fertilisers excluding nitrogen resulted in relatively healthier pollinator and flower counts, pinpointing nitrogen’s role in the destruction.
Pollinators, including bees, butterflies, and other insects, are critical for maintaining ecosystems and ensuring agricultural productivity. Nearly a quarter of Earth’s land area is agricultural grassland, sustaining the livelihoods of over 800 million people. However, fertilisation practices, while boosting food production, have led to biodiversity loss, pollution, and now, the potential collapse of ecosystems reliant on pollination.
When nitrogen fertilisers dominate, fast-growing grasses outcompete diverse flowers, reducing floral variety and, consequently, the diversity of pollinators. Dr. Balfour suggested reducing grassland production intensity to foster multifunctional landscapes with balanced ecological benefits.
The Park Grass Experiment, established in 1856, began as a study to enhance pasture productivity through fertilisation. Over its 169-year history, it has evolved into a vital resource for understanding ecological and environmental dynamics. The experiment has consistently provided insights into agroecological systems and their responses to various interventions.
This study marks another milestone for Park Grass, emphasizing the global importance of managing agricultural practices to mitigate environmental damage.
Reducing fertiliser dependency, especially nitrogen-based ones, and promoting chemical-free agricultural practices could restore pollinator populations and floral diversity. Encouraging multifunctional landscapes with a variety of flowers could lead to healthier ecosystems and sustainable farming practices.
