Effects of sewage sludge and its biochar on soybean yield in fine-textured loess soil

Abstract

Background: The application of biochar as a soil amendment has achieved popularity and has been found to improve considerably soil nutrient status and plant productivity in low fertile soils. Methods: This study used two different methods to apply sewage sludge and sewage sludge biochar with three replicates in a completely randomized block design. The experiment included (1) control, (2) mulch biochar (20 t/ha), (3) incorporated biochar (20 t/ha), (4) mulch sewage sludge (45 t/ha), and (5) incorporated sewage sludge (45 t/ha). This study aimed to investigate the potential benefits of sewage sludge and its biochar as mulch and incorporated into the top-soil for soil fertility, growth, yield, and shoot nutrient concentration of soybean and the effects of treatments on dry bulk density, water content, and mechanical resistance. Results:The results showed higher values of height, biological yield, grain yield, and number of pods in the biochar mulch treatments (116.5, 10627.01, 4180, and 71.2, respectively). Moreover, it was determined that the addition of biochar and sewage sludge to soil resulted in increased shoot nitrogen (N), phosphorous (P), and potassium (K) concentrations, soil P, soil K, and total soil N (TN) compared with the control plots. Results from this study also showed that biochar and sewage sludge had positive impacts on the physical properties of soil. Bulk density and soil mechanical resistance were decreased, and volumetric water content was increased. Conclusion: Heating sludge removed all pathogens. It is recommended that short-and long-term studies be conducted in the region to investigate further increases in the combined biochar and sewage sludge application rates. Keywords: Nitrogen (N), Phosphorous (P), Potassium (K), Pathogens Citation: Fathi Dokht H, Movahedi Naeini SA, Dordipour E, De Jong LW, Hezarjaribi E. Effects of sewage sludge and its biochar on soybean yield in fine-textured loess soil.

Antibiotic resistance genes and mobile genetic elements removal from treated wastewater by sewage-sludge biochar and iron-oxide coated sand

“…Pyrolysis is done under less or no oxygen conditions which reduces the amount of flue gases to be cleaned and acidic gases generation (Hwang et al, 2007). Biochar produced out of dewatered sewage-sludge has been shown to be useful in removing pollutants from wastewater (Fathi Dokht et al, 2017). The ability to remove nucleic acids is an additional advantage of this byproduct material on top of removing agrichemicals, pharmaceuticals and personal care products as well as endocrine disrupting compounds (Thompson et al, 2016).…”