The Influence of Sewage Sludge and a Consortium of Aerobic Microorganisms Added to the Soil under a Willow Plantation on the Biological Indicators of Transformation of Organic Nitrogen Compounds

Abstract

The aim of our three-year study was to determine the infl uence of sewage sludge and a consortium of aerobic microorganisms (BAF) on the dynamics of the development and activity of proteolytic and ammonifying bacteria, soil plant analysis development (SPAD), and the ratio of the leaf assimilation area in willows. Four experimental variants were used in the study: control, soil with sewage sludge, soil with sewage sludge and the BAF inoculant, and soil with the BAF inoculant. The experiment was conducted on the Start willow cultivar. In each year of our research (2013-15), soil samples for microbiological and chemical analyses were collected three times -in spring, summer, and autumn (in May, July, and September).The research involved the application of the Koch plate method to measure the count of proteolytic and ammonifying bacteria, and spectrophotometry to determine protease and urease activity. The green seeker index (SPAD) was measured by means of non-destructive methods with a SPAD index. The ratio between the willow leaf assimilation area and leaf area (LAI) was measured by means of the SunScan Canopy Analysis System. The content of chlorophyll a and b was analyzed by means of dimethyl sulfoxide extraction.The highest count and activity of proteolytic bacteria was observed in the soil in the third year of the experiment. Urease exhibited the highest activity in the second year of the research. Sewage sludge stimulated the proliferation and activity of proteolytic bacteria, the content of chlorophyll a and b, the leaf assimilation area, and the green seeker index (SPAD).

The effect of sewage sludge and BAF inoculant on plant condition and yield as well as biochemical and microbial activity of soil in willow (Salix viminalisL.) culture as an energy crop

“…Sewage sludge following its application to soil becomes a source of available organic carbon and macronutrients, thanks to which they stimulate microbial growth and enzymatic activity. Similar relationships of microbiological and biochemical activity were noted for nitrogen transformation analyses ( Wolna-Maruwka et al, 2018 ). The authors noted that in relation to the control object all combinations used with the addition of sewage sludge contributed to a significant increase in the assimilation area of leaves and the nutritional status of plants with nitrogen (SPAD).…”

“…One concerning the transformation of carbon in the soil after the application of sludge (presented here) and the second concerning the transformation of nitrogen. The latter one regarding nitrogen transformation was published by Wolna-Maruwka et al, 2018 . Field trials were conducted as unifactorial experiments in four replications.…”

Soil bacterial community structure at different plant maturity stages in an annual grass–legume production system

“…However, it is not sufficient to assess soil fertility based on physical and chemical properties alone. Measurement of microbial and enzymatic indicators in the soil can provide a more complete understanding of the transformations that are taking place and affecting soil fertility and nutrient capacity (Wolna-Maruwka et al, 2018). In the present study, soil enzyme activities varied markedly among plant maturity stages, especially for enzymes associated with the nitrogen cycle.…”

Indices of Soil and Plant Cover Pollution Due to Re-Introduction of Sediment Water Under the Energy Willow on Aluvisol of Ukraine

“…As a result, this led to a significant increase in microbial biomass, an increase in soil enzymes -phosphatase, dehydrogenase, urease. The application of SS also increased the available forms of heavy metals (Ni, Cr, Pb, Cu and Cd) in the soil, but below the threshold values [ In willow plantations, after harvesting biomass, after repeated application of SS, plant survival, height growth intensity, net photosynthetic productivity, permeability through leaf stomata and transpiration, as well as the number of regrown shoots in plants significantly increase [Wolna-Maruwka A., Sulewska H., Niewiadomska, A. et al, 2018]. The issue of safe dosing of the introduced SS remains unexplored, since it is the dose that is the factor of contamination of the soil environment.…”