Effects of a Zeolite-based Foliar Biostimulant on Winter Wheat and Maize

Foliar applications of a zeolite-based biostimulant improved the yield as well as the export of nitrogen of winter wheat and maize. This represents an option for improving nitrogen use efficiency and reducing losses.

Boosting yields, optimising nutrient use efficiency and reducing ecological impact are just three of the many challenges facing the agricultural sector. One option for meeting these challenges is represented by plant biostimulants, which have been used for decades to stimulate plant growth and improve certain functions.

A field test conducted by Agroscope to determine the effects of a zeolite-based inorganic biostimulant on winter wheat and maize cultivated along a nitrogen fertilisation gradient is being hailed as groundbreaking. The study shows that the biostimulant increases wheat and maize yields at the lowest nitrogen fertilisation rates, due in particular to a higher number of seeds per m². The results also indicate an increase in nitrogen use efficiency for the lowest nitrogen fertilisation levels.

Biostimulant use results in higher grain yields

The test was conducted at Agroscope’s experimental site in Nyon during the 2022 and 2023 seasons. Two experimental factors were taken into account: the level of nitrogen fertilisation and the foliar application of zeolite. Nitrogen was applied at four levels (50, 85, 120 and 155kg N ha^-1). For each level, a natural zeolite-based biostimulant (chabazite) was applied by foliar spraying over half of the field.

The results show an average increase in grain yield of 6.7% over the entire nitrogen fertilisation gradient for winter wheat and of 7.2% at the lowest nitrogen fertilisation rates (50 and 85kg N ha^-1) for maize. This is explained by an average increase in the number of grains per m² of 6% for winter wheat over the entire nitrogen fertilisation gradient and of 7.9% and 9.3% for maize at the nitrogen fertilisation rates of 50kg N ha^-1 and 85kg N ha^-1, respectively. Harvest indices also increased by 6.3% for winter wheat and 7.2% for maize at the lowest nitrogen fertilisation rates.

More efficient use of nitrogen

No dilution of nitrogen concentration in the grains was observed following the application of the biostimulant on the winter wheat and maize, highlighting the increased export of nitrogen into the grains, particularly at the lowest fertilisation levels. This is indicative of greater nitrogen use efficiency.

This result allows us to consider the possibility of reducing the quantity of nitrogen fertiliser whilst maximising nitrogen export, leading to lower environmental losses.

However, future studies are necessary, both to confirm the positive effects of the biostimulant under other pedoclimatic conditions and for other crops, to better understand the plants’ response mechanisms to the application of the biostimulant, and to shed light on the economic aspects.