Evaluation of suitability of treated sewage sludge for maize cultivation

The growing population of the world demands more food and creates more waste. Economically viable and environmentally friendly would be to use sewage sludge for agricultural production. There are several limitations for this use – heavy metal content, pathogenic microorganisms, helminths etc. Different methods of treatment of sewage sludge help to overcome these problems. The aim of this study is to evaluate the effects of treated sewage sludge on growth of maize and biological activity of soil. To carry out experiments, dry sewage sludge (DSS) was prepared in the following combinations: 1) sewage sludge preparation (SSP), 2) SSP with additional phosphorus and potassium, 3) SSP with additional nitrogen, phosphorus and potassium. Loamy soil without additional fertilizer and soil mixed with mineral fertilizer (Kristalon 18:18:18) were used as controls. Maize (Zea mays var. saccharata ‘Elan F1’) was grown for the study. Corn was grown in 1 L vegetation containers that were placed in an open area with additional watering. Plant growth parameters and enzymatic activity of soil were monitored. SSP alone or in combination with potassium and phosphorus fertilizers does not provide maize with mineral nutrients in appropriate amounts, therefore, a combination of SSP with nitrogen containing fertilizers significantly improves plant growth and promotes development. The use of SSP increases the microbiological activity of soil. This can have a beneficial long-term effect on the mineral nutrition of plants.