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Fertilisers Make Plants Weaker

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As well as causing soil damage and environmental problems from run-off, research published in Proceedings of the Royal Society of London B (http://tinyurl.com/hzwkj58) has found that nitrogen-based fertilisers also reduce a plant community’s resistance to fungal diseases. The researchers warn that prolonged use of artificial fertilisers can lead to the extinction of the most resistant plant species in a community, making the remaining species more susceptible to diseases.

In experimental field trials, researchers from Flinders University in Adelaide and Fudan University in Shanghai tested the biodiversity resilience of an isolated plant community in a native alpine meadow on the Qinghai–Tibetan Plateau. The 20-hectare experimental meadow, which has been spared from yak grazing for the past 20 years, contains a rich and diverse plant community.

“In this diverse and pristine ecosystem, we have established that extended fertilisation of soils not only alters the structure of natural plant communities, it also exacerbates pathogen emergence and transmission,” the researchers concluded.

Prof Corey Bradshaw of Flinders University says that this is one of the ways in which crop monocultures succumb to sudden outbreaks of severe disease. “Having more species in an ecosystem provides a...

The full text of this article can be purchased from Informit.