Residual effects of biosolids and farm manure on speciation and plant uptake of heavy metals in a calcareous soil

Abstract

Application of biosolids to agricultural land can improve soil fertility and physical properties. However, the bioavailability of heavy metals in soil may increase after cessation of biosolids application. In this study, chemical speciation and plant availability of Cu, Ni, Pb, and Zn were investigated 3 years after application of 0 (control), 25, 50, and 100 Mg ha -1 of biosolids (BS) and farm manure (FM) to a calcareous soil. Results showed that Pb and Ni concentrations in the grains of wheat grown in the BS and FM treatments were significantly lower than those grown in the control. Meanwhile, the concentrations of Zn and Cu were greater in the grains of wheat grown in the BS-and FMamended soils compared to those grown in the control soil. The concentrations of DTPA-extractable Zn, Cu, Pb, and Ni in the biosolid-amended soils were significantly higher than those in the control soil. The results of sequential extraction showed that majority of Cu, Zn, and Ni were in residual fraction, while Pb bound mainly with Fe-Mn oxides. From the environmental point of view, the residual fraction of heavy metals is less bioavailable under the conditions normally found in calcareous soils. On the basis of the heavy metal speciation, the mobility factor values did not change 3 years after application of the amendments.

Fractionation, Bioaccessibility, and Risk Assessment of Heavy Metals in the Soil of an Urban Recreational Area Amended with Composted Sewage Sludge

“…The increasing trend in concentrations of some heavy metals in plant tissues with SS addition rate and an inhibitive effect on plant growth due to excessive application have been recorded in the literature [ 9 , 10 , 11 , 12 , 13 ]. Some researchers have worked on the fractionation of heavy metals in SS and SS-amended soils to estimate their mobility and availability to plants [ 14 , 15 , 16 , 17 , 18 ]. For example, Bai et al [ 14 ] observed that the increment of metal uptake by maize grown in the SS-amended mudflat saline soil was determined by the increment of available metal concentrations (viz.…”

Organic Materials and Their Chemically Extracted Humic and Fulvic Acids as Potential Soil Amendments for Faba Bean Cultivation in Soils with Varying CaCO3 Contents

“…In this concern, the application of 100% organic amendment (T 2 ) recorded the highest increases in plant dry weights, while the least dry weight value was attained for the non-amended control treatment (T 0 ). These results can probably be attributed to the findings that indicate that organic amendments raised soil fertility considerably, especially in both light-textured [10] and calcareous soils [14]. They may also promote plant growth bacteria as well, and this consequently stimulated plant development [60].…”

“…Accordingly, organic applications are guaranteed to attain these aims [8]. These amendments not only improve soil physical and chemical characteristics [9][10][11][12] but also chelate nutrients [13] and increase their availability, especially in alkaline and calcareous soils [14]. Even in acid soils, organic amendments can maintain the optimal pH for nutrient availability [15].…”

Environmental risk assessment in livestock manure derived biochars

“… 2 Meanwhile, feedstock additives were used to prevent disease of animals and promote the growth of animals, resulting in high content of heavy metals in manures. 3 Long term application of animal manures sustaining high concentrations of heavy metals can lead to elevating concentrations of soil heavy metals, 4 which subsequently harms crop and humans through the food chain. 5 Therefore, the appropriate management and treatment of livestock manure are issues of increasing concern.…”