Effects of sewage sludge application on the some biological activities in the rhizospheres of common bean and corn

Abstract

Significant population growth has generated several problems over the last half century. Due to the increased land use, the amount of fertile land is constantly decreasing. Minerals released from the soil by crop production and extraction needs to be replenished, as its self-sustaining mechanism cannot reverse such damage. The utilization of sewage sludge is playing an increasingly important role in the field of environmental protection due to the expanding sewerage network. The further storage, treatment and disposal of sewage sludge generated as a by-product during wastewater treatment are a significant problem for wastewater treatment plants, mainly due to the increasing volume. However, its special feature is that, despite being a waste, it is an important source of nutrients that, when returned to the soil, improves its quality. The aobjective of the study was to measure the effect of sewage sludge on soil biochemical properties and its remedial effect. In the course of the research, soil samples were treated with different proportions of sewage sludge for the biological activities measurements. The study was carried out in the rhizospheres of two plant species (common bean, maize), to measure the enzyme potencial activity of urease, ß-glucosasease, dehydrogenase, and phosphatase based on the content of sewage sludge. Based on the results of the study, it can be concluded that the application of organic waste sludge improves the quality of the soil in all cases, however, after 15% treatment, a significant change can be observed; there was a spectacular increase in soil enzymatic potencial activity of the investigated enzymes. Finally, the study covers the situation of domestic agriculture and the legal framework of sewage sludge disposal.