Biostimulanten: soorten en werkingsmechanismen

Biostimulants are increasingly used in agriculture and horticulture as methods are sought to limit the use of artificial fertilizers and pesticides. These products may contain microbial or non-microbial substances as well as combinations thereof. Biostimulants are defined as products that stimulate the plant nutrient supply, independent of the nutrient content of the product, with the sole purpose of increasing plant nutrient use efficiency, tolerance to abiotic stress, the availability of nutrients retained in the soil or in the rhizosphere and improving overall quality characteristics of the plant increasing. This report describes the different types of microbial and non-microbial biostimulants and discusses the knowledge that is available regarding their modes of action. The mechanisms behind the effects of these products differ, but there is also substantial overlap. Many products have an effect on the resistance and resilience to both abiotic and biotic stress by means of effects on plant hormones and plant physiology or through effects on soil resistance and resilience (e.g., the microbiome). Despite the enormous amount of knowledge that has been gathered about biostimulants in recent years, many open questions and obstacles remain in their application. The main obstacles in practical use are uncertainty about the exact composition of products and the conditions (e.g. abiotic conditions, crop, growth phase) under which the products are most effective.