Using legumes to supplement nitrogen

While all cover crops add some nitrogen to the soil, legume cover crops are the big contributors, owing to their ability to fix nitrogen.

On average, for every tonne of shoot biomass grown, approximately 20kg of nitrogen will be added.

A good legume cover crop with the right inoculant can produce 8-10 tonnes of shoot biomass, which equates to 160-200kg of nitrogen added. Cover crop roots can add a further 30-100kg of nitrogen.

In Issue 08 of PotatoLink magazine, Paulette Baumgartl writes a compelling article explaining the biology of ‘cheap nitrogen’ including tips to get the most nitrogen out of your legume cover crop.