Impact of Fertilisers on Pollinators and Biodiversity

Recent research conducted at the Park Grass Experiment in Rothamsted, England, has revealed alarming vital information about the impact of common fertilisers on pollinator populations and flowering plants. The two-year study, published in January 2025, marks decline in both pollinator richness and flower abundance in plots treated with high levels of nitrogen, phosphorus, potassium, and magnesium. This study puts stress on the critical relationship between fertiliser use and ecological health.

Background of the Park Grass Experiment

The Park Grass Experiment is renowned as the longest-running ecological study in the world, initiated in 1856. Its primary objective was to assess the effects of various fertilisation methods on pasture productivity. Over the years, it has evolved to provide vital information about broader ecological dynamics, particularly the interaction between agricultural practices and biodiversity.

Key Findings on Pollinators

The study found that the population of pollinators, especially bees, was halved in plots receiving high fertiliser inputs. In untreated plots, pollinator abundance was nearly doubled compared to those with excessive fertiliser use. This stark contrast marks the detrimental effects of fertilisers on these essential species.

Impact on Flowering Plants

The research indicated a five-fold decrease in flower abundance in fertilised plots. Untreated areas exhibited 5.18 times more flowers and 8.46 times greater species richness. The excessive use of fertilisers favoured fast-growing species, primarily grasses, at the expense of diverse flowering plants.

Role of Nitrogen in Ecological Decline

Nitrogen was identified as the primary culprit in the decline of pollinator populations. Plots treated with fertilisers that excluded nitrogen showed relatively high numbers of both pollinators and flowers. This finding suggests that managing nitrogen levels could be crucial for preserving biodiversity.

Implications for Agriculture and Ecosystems

The decline in pollinator populations poses a threat to agricultural productivity and the stability of natural ecosystems. Pollinators play a vital role in the reproduction of many crops and wild plants. The study calls for a reevaluation of fertiliser use in farming practices to mitigate these negative effects.

Recommendations for Sustainable Practices

To protect pollinator populations and enhance biodiversity, farmers are encouraged to adopt sustainable practices. These include reducing fertiliser use, implementing organic farming methods, and promoting diverse planting strategies. Such measures can help restore ecological balance and support vital pollinator species.

Questions for UPSC –

1. Critically discuss the impact of agricultural practices on biodiversity in the context of the Park Grass Experiment.
2. Examine the relationship between fertiliser use and pollinator health in modern agriculture.
3. Analyse the role of bees as pollinators in agricultural ecosystems and their significance to food security.
4. Estimate the long-term effects of nitrogen fertilisation on soil health and plant diversity.

Answer Hints:

1. Critically discuss the impact of agricultural practices on biodiversity in the context of the Park Grass Experiment.

1. The Park Grass Experiment marks the long-term effects of different fertilisation methods on biodiversity.
2. High fertiliser inputs have led to reduction in flower abundance and pollinator species richness.
3. Fast-growing species, like grasses, dominate fertilised plots, reducing overall plant diversity.
4. Untreated plots showed a richer ecosystem with more diverse flowering plants and pollinators.
5. The findings call for a reconsideration of intensive agricultural practices to protect biodiversity.

2. Examine the relationship between fertiliser use and pollinator health in modern agriculture.

1. The study found a direct correlation between high fertiliser use and decreased pollinator populations.
2. Pollinator abundance was nearly doubled in untreated plots compared to those with high fertiliser levels.
3. Nitrogen was identified as the most harmful element affecting pollinator health.
4. Reduced pollinator health threatens agricultural productivity and ecosystem stability.
5. Strategies to lower fertiliser use are essential for improving pollinator health in agriculture.

3. Analyse the role of bees as pollinators in agricultural ecosystems and their significance to food security.

1. Bees are crucial for the pollination of many crops, directly impacting food production.
2. The study revealed a drastic decline in bee populations in fertilised plots.
3. Healthy bee populations enhance crop yields and biodiversity in agricultural systems.
4. Declines in bee populations threaten food security and the stability of ecosystems.
5. Conservation efforts for bees are necessary to ensure sustainable agricultural practices.

4. Estimate the long-term effects of nitrogen fertilisation on soil health and plant diversity.

1. Nitrogen fertilisation can lead to soil degradation and loss of microbial diversity over time.
2. Excess nitrogen promotes specific fast-growing species, reducing overall plant diversity.
3. Long-term nitrogen use can disrupt nutrient cycles and harm beneficial soil organisms.
4. Managing nitrogen levels is essential for maintaining soil health and plant diversity.
5. Adopting sustainable fertilisation practices can mitigate negative long-term impacts on ecosystems.