A new plant biostimulant called BlueN claims to produce the equivalent of 20-30kg N/ha in plant leaves following the application of a specific species of bacterium. It has just been launched on the Irish market for 2023.

The product is sprayed on to plant leaves and the bacteria enter the leaf through the stomata (breathing pores) on the surface and colonise the tissue. In there, they take nitrogen gas from the air in the leaf and convert it to ammonium for use by the plant.

BlueN is a new technology compared with pulses and legumes. These use bacteria in nodules on the plant roots to capture gaseous nitrogen and convert it to a plant-available form to supply the full nitrogen needs of the growing crop.

The product has just been launched by Corteva Agriscience and its use is being examined on a range of crops. Its effectiveness in a plant is influenced by growth rate and therefore by temperature post application. It is also influenced by the length of the growing season.

It is most useful when the plant is growing actively. Most research was done on annual crops with a single harvest date such as cereals, oilseed rape, maize, potatoes, beet and even legumes. Less is known about its usefulness on grass to date as the removal of the leaf through grazing or silage may require repeat applications to be effective. However, this research is now ongoing. Ultimately, the product can help reduce reliance on artificial fertiliser while improving the efficiency of applied nutrient. Such products (there are others reported also) could be beneficial in the fight against greenhouse gas emissions.

BlueN is the first such product to be made available to Irish farmers following collaboration between Corteva and Symborg – a biological company acquired in late 2022.

The product contains Methylobacterium symbioticum, an endophytic bacteria which works in harmony with the plant. Basically, this bacteria transforms atmospheric nitrogen (N2), which is not available to the plant, into ammonium (NH4), which is available.

BlueN will be available in 2023 and distributed through Terrachem.