Composting is a process of the biological decomposition of organic matter under aerobic conditions. Composts made from waste may still contain other substances that influence plant growth and development, such as vitamins or plant growth substances (plant hormones). Application of products containing phytohormones has an effect on numerous physiological processes in plants. Among observable results are: improved condition of the root system, increased absorption of nutrients, improved stress and disease resistance and delayed aging. The purpose of the research was to analyse the occurrence of plant hormones in mature composts made from selectively collected organic fraction of household municipal solid waste. Solid waste processing was carried out in a composting plant located at the Municipal Waste Management Plant in Żywiec (Silesian Province, Żywiecki District, Poland). The composting plant uses a Herhor bioreactor. Organic waste constituted 70% of the mixture, with the remaining 30% composed of structural material. Regarding the varying amounts of green waste (mainly grass clippings), the composts were divided into two groups: early spring composts and late spring composts. Four out of the five analysed substances (from the auxin and cytokinin groups) were found in composts made from waste collected in early spring. Composts made from waste collected from May to June contained mostly cytokinins and gibberellic acid. Total concentration of plant hormones in the composts was related to the content of plant waste in processed material.

22.4.2016