The Dutch biologial controls and stimulants supplier said a study at the PlantResearch station in Made found that Naturgro enabled a reduction of both NH4+ and NO3- use by an average of 19 per cent against a control.
According to PlantResearch senior researcher Ron Galiart: "Fertigation is an important cost factor for a grower, but over-fertigation may also lead to spills into the environment, even from recirculation systems.
"Therefore reducing nitrogen levels without affecting overall yield , as achieved by the Koppert Natugro products ProFortum and ProTerrum, is beneficial on several levels."
Dutch grower and packer Grerenco has already incorporated Naturgro into its tomato fertigation. Mark van der Werf of the company said: "We have seen absolutely no negative effects in the crop. In fact, it seems to have a positive effect on the plant's susceptibility to diseases and pests."
Koppert's head of microbials field development Katja Hora added: "It looks fair to assume we can reduce the nitrogen levels even further - something we will look at in the near future."