Giant reed (Arundo donax L., Poaceae) is a robust, perennial, rhizomatous grass with C3-type photosynthesis. This plant is utilised in different parts of the world for industrial, construction, agricultural, environmental and bioenergetical purposes. Because its above-ground organs can produce annually 10–20 dry tonnes per hectare without irrigation, this plant is a perspective energy crop in Hungary. An open-field microplot experiment was set up with Arundo between 2009–2010 in Nyíregyháza (Hungary). The sandy loam brown forest soil was treated in June 2009 and July 2010 with ammonium nitrate (AN – 150 and 300 kg ha-1) fertiliser as top dressing, with municipal biocompost from green waste (MBC – 25 t ha-1 wet weight), and with municipal sewage sludge compost (MSSC – 25 t ha-1 wet weight). The most important microanatomical parameters of Arundo leaves were examined in October 2010. It was found that both AN, MBC and MSSC reduced the thickness of the epidermis. All treatments expanded the width of vein islands between the parallel veins, and the number of epidermis cell lines of the vein islands. The MBC and MSSC treatments caused a significant increase in stoma number, while AN treatments bring about increase of stoma width.

It can be concluded that the soil treatments – by the help of improving nutrient supply – take a complex effect on the leaf anatomy. The positive influence is mostly expressed in the increase of stoma number. The higher stoma number makes a higher rate of CO2-accumulation possible, which contributes to a higher biomass production of Arundo.

Keywords: Arundo donax, artificial fertiliser, compost, leaf, microanatomy