Microbial Diversity and P Content Changes after the Application of Sewage Sludge and Glyphosate to Soil

Abstract

Pesticides, despite their side effects, are still being used in almost every agriculture, horticulture, maintaining municipal greenery in urban areas and even in home gardens. They influence human life and health and the functioning of entire ecosystems, including inanimate elements such as water and soil. The aim of the study was the evaluation of the suitability of sewage sludge in improving the quality of soil treated with a non-selective herbicide-glyphosate, applied as Roundup 360 SL. A pot experiment was conducted with the use of two arable soils (MS and OS), which were amended with sewage sludge (SS), glyphosate (GL) and sewage sludge with glyphosate (SS+GL). Soil samples were taken after 24 h, 144 h and 240 h and total phosphorus (TP) content (TP), total number of bacteria/fungi, activity of dehydrogenases (Dha), acidic phosphatase (Acp), alkaline phosphatase (Alp), genetic biodiversity of bacteria/fungi using the terminal restriction fragment length polymorphism method were determined. The application of SS and GL to OS caused an increase in Acp (approximately 35%) and a decrease in Alp activity (approximately 20%). Additionally, GL may influence on an increase in the number of fungi and the decrease in the number of bacteria. In soil with SS+GL increase in the fungal diversity in MS and OS was also observed. Moreover, a positive between TP and the number of bacteria and the activity of phosphatases correlation was reported. The obtained results indicate that analyzed sewage sludge could be potentially applied into soil in in situ scale and could constitute a valuable reclamation material.