Bioavailability of heavy metals to maize grown in sewage sludge amended soil
Loading...
![Thumbnail Image](assets/images/Item.jpg)
Date
2020
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Punjab Agricultural University, Ludhiana
Abstract
Sludge generated from the sewage treatment plants (STPs) has a potential for its use in
agriculture, as it contains a good amount of organic carbon as well as macro and micro
nutrients. However, due to the presence of heavy metals, its use in agriculture is restricted. If
used judiciously, it can become one of the alternates to the organic manures. A field
experiment was conducted at the research farm of Department of Soil science, PAU,
Ludhiana to evaluate the different rates (0, 2.5, 5, 7.5 and 10 t/ha) of sewage sludge along
with three different levels of nitrogen (0, 90, 120 kg N/ha) on dry matter yield of maize (Zea
mays var PMH 1) and to study the bioavailability and transformations of heavy metals in
post-harvest soil. Application of sewage sludge up to 5 t/ha along with 120 kg N ha-1increased
the maize grain and stover yield significantly. The maize grain yield increased from 30 q/ha in
absolute control to52.6 q/ha and maize stover yield increased from 67 q/ha to 109.6 q/ha with
the application of sludge @5 t/ha along with 120 kg N/ha. Heavy metals (cadmium,
chromium, lead and nickel) content in maize grain and stover and their uptake also increased
significantly with the increasing rate of sludge application. The mean cadmium, chromium,
lead and nickel content in maize grains increased from 0.015 to 0.032 mg/kg, 0.629 to 0.698
mg/kg, 0.157 to 0.195 mg/kg and 0.93 to 1.61 mg/kg, respectively with the highest rate of
sludge application. These concentrations were within the respective permissible limit given by
FAO/WHO. Sequential fractionation of post-harvest soil samples suggested that proportion of
Cd and Pb to their total content significantly increased in the labile fraction of soil pool and
percentage of Ni and Cr to total significantly increased in the residual fraction with
application of 10 t/ha sludge over control. Application of 5 t/ha could be more sustainable
approach for a longer period.
Description
Keywords
Citation
Gupta, Soura Shuvra (2020). Bioavailability of heavy metals to maize grown in sewage sludge amended soil (Unpublished M.Sc. thesis). Punjab Agricultural University, Ludhiana, Punjab, India.