Legumes such as clover are incredibly important for nitrogen cycling, particularly in New Zealand. In the early days, when we didn’t have nitrogen fertilisers, they encouraged the growth of nitrogen fixers by adding phosphorous fertilisers. And the neat thing about clover is that it harbours a bacteria called rhizobia and houses them and encourages them to grow, and they will take dinitrogen gas out of the atmosphere and convert it through to ammonia and ammonium that the plant can then use. That nitrogen ultimately ends up getting into the soil and taken up by other plants. So clover growth has hugely increased the production of New Zealand pastures.
Professor Louis Schipper, University of Waikato
Professor Frank Dazzo