Effect of untreated and NH₄-charged Chabazite on growth and nitrogen uptake of Photinia fraseri ‘Red Robin’

Amendment of growing media with Chabazite, a natural zeolite with a high ammonium sorption capacity, in combination with ammonium fertilization might be a promising approach to reduce nitrogen leaching in container nurseries.
However, it is unclear if ammonium, which is adsorbed to Chabazite is still plant-available.
Thus, a pot trial with Photinia fraseri was conducted with growing media containing 25 vol % of either pumice or Chabazite.
Chabazite firstly was used as received and secondly was charged with two levels of ammonium resulting in nitrogen loads of 1 and 5 g N pot^‑1, respectively.
The untreated Chabazite was fertilized with 1 g N pot^‑1 as ammonium sulfate divided in repeated applications in accordance with the control (pumice). In these two treatments plant growth and nitrogen uptake was more or less the same.
Plants in the growing media with NH₄-charged Chabazite receiving also 1 g N pot^‑1 produced a significantly lower fresh mass compared to the untreated Chabazite and pumice and suffered from slight nitrogen deficiency.
If 5 g N pot^‑1 were applied with charged Chabazite, plants grew better and took up more nitrogen.
The results indicate that Chabazite did not influence negatively plant availability of fertilized ammonium.
However, ammonium from charged Chabazite is only partly plant-available.
With increasing NH₄ charging of Chabazite, ammonium and nitrate accumulated in the growing media.

IV International Symposium on Horticulture in Europe – SHE2021

A. Bucher, D. Lohr, E. Meinken

zeolite, ammonium adsorption, growing medium, nursery

https://doi.org/10.17660/ActaHortic.2021.1327.18