Sewage sludge as a source of microelements regarding fodder value of spring wheat grain

Abstract

Agricultural alternative for utilization of municipal sewage sludge from some treatment plants, despite still existent doubts, seems the most optimal solution. The condition, which must be fulfilled for such use of sewage sludge are not only legal restrictions, but also dosage of these materials – well considered and justified by agrotechnology. Therefore, the research aimed at determining whether the use of municipal sludge for fertilization would lead to diversification of the contents of selected microelements in spring wheat grain regarding its fodder value. The experiment was conducted in field conditions on the soil classified to Stagnic Gleysol. Zinc, copper, manganese and iron were assessed after dry mineralization of the material by ICP-AES method. On the basis of obtained results it was stated that application of sewage sludge in moderate doses, in compliance with plant requirement for nutrients did not cause any excessive accumulation of the analysed microelements in wheat grain. However, it should be stated that the problem does not concern only microelement content but also the relationships between them, as has been confirmed on the basis of value of Fe:Mn ratio, which indicated manganese deficiency in the analysed grain, irrespective of the applied fertilization.