Fertilised fields put plant diversity in the shade

The 35-year-old mystery of why fertilisers decrease biodiversity has finally been solved. The secret? They increase competition for sunlight.

Adding fertilisers to grasslands increases the productivity of plants, but leads to a major drop in biodiversity.

The amount of nitrogen and phosphorus available to plants has doubled in the last 50 years, but the reason why this has harmed diversity has not been easy to answer. The debate has centred on whether fertilisers increase competition above or below ground