THE EFFECT OF GLYCEROL BY-PRODUCT ON THE DEVELOPMENT OF MAIZE AND ZINC UPTAKE

RÉTHÁTI, G. – A. VEJZER – B. SIMON – Zs. VADKERTI – L. TOLNER

Department of Soil Science and Agricultural Chemistry, Institute of Environmental Sciences, Faculty of Agricultural and Environmental Sciences, Szent István University, H-2103, Gödöllő, Páter K. u. 1. Hungary, Rethati.Gabriella@mkk.szie.hu

Abstract: Biodiesel production belongs to the environmentally sound technologies supported by the EU. During the production significant amount of (crude) glycerol is produced, as by-product. The glycerol content of this by-product is nearly 50%. Beside, it contains macro and microelements valuable for plants, methanol and potassium hydroxide in high amounts. With appropriate cleaning technology it is utilized in agriculture (in composts, mixing it with liquid manure, or forage), however, there is only a few studies made about its direct effect mixed into the soil. Our objectives were to find out 1) the effect of glycerol by-product on the Zn uptake of maize, and 2) to examine if it has any effect on the different developmental stages of maize. In pot experiments, soil (acidic brown forest soil, Gödöllő) were incubated for two weeks with glycerol and known amount of Zn. Treatments (3 replicates): (I) control, (II) 1% glycerol, (III) Zn: 100 mg kg-1, (IV) 1% glycerol + 100 mg kg-1 Zn. The experiments were carried out in several developmental stages: swelling, germination, emergence, 2-3 and 3-4 leaf-stages. Dry matter yield, dry matter %, Zn concentration and uptake by plant (shoot, root) were examined. Conclusions: small-scale inhibiting effect of glycerol by-product was found in the beginning of the development of maize (seedling formation, emergence). However, this effect decreased by time and it did not show significant difference at 3-4 leaf-stage between the control and the treated plants. The Zn uptake by maize was not inhibited by mixing the glycerol by-product into the soil, however, the Zn uptake of samples (IV) treated with Zn and glycerol at the same time, was significantly lower than the samples that had only Zn (III), but not glycerol treatment.

Keywords: glycerol by-product, maize, Zn uptake, development of maize