Environment

Intensive Fertiliser Use Dampening Natural Nutrition

The widespread use of nitrogen fertiliser is causing a significant evolution in soil bacteria that naturally help bring nitrogen to many plants, making the organisms less beneficial to legumes.

Researchers from the University of Illinois at Urbana-Champaign say the changes in soil rhizobia could have “far-reaching ecological and environmental consequences,” not only in farmland, but also in the plants of the surrounding environment.

Writing in the journal Evolution, the scientists say the problem isn’t limited to the application of fertiliser on legumes.

Lead author Katy Heath says emissions of nitrogen oxides from the burning of fossil fuels are also causing a change in the quality of soil rhizobia, leading to altered plant growth.

“Worldwide, the nitrogen cycle is off. We’ve changed it fundamentally,” said Heath.

The research reveals that in areas polluted with fertiliser runoff, legumes decline while other plants become more common.

Root nodules house soil bacteria, like rhizobia, which fix nitrogen for the plant. The bacteria cannot fix the nitrogen on their own and need a plant host.