Effect of tannery sludge amendments on the activity of soil enzymes and phytoremediation potential of two economically important cultivars of geranium (Pelargonium graveolens)

ABSTRACT

A field experiment was conducted to observe the effect of TS amendments on soil enzymes and phytoremediation potential of two economically important cultivars of geranium. Different doses of TS were applied in soil to examine threshold limit of HMs where geranium cultivars can be grown successfully in contaminated sites. Treatment variation significantly affected pH, EC, OC, N, P, K and HM content in soil after 50 days of incubation. After harvest, both cultivars were examined to assess the impact of various treatments on their fresh herb, dry matter, essential oil yield and HM accumulation. C/G ratio close to 1 was observed at 50 tha⁻¹ sludge treatment in both cultivars. Urease and β-glucosidase activities in soil were maximum at 50 tha⁻¹ whereas dehydrogenase and phosphatase activities were maximum at 100 tha⁻¹ in both cultivars. β-glucosidase, acid and alkaline phosphatase, urease and dehydrogenase activities were relatively high after 85 days over 45 days in both cultivars. Maximum metal uptake was found in roots of cv. Bourbon followed by leaves. Geranium was observed to be a good candidate for phytoremediation as it mitigates metal toxicity by root absorption and cv. Bourbon is better candidate for the same.

GRAPHICAL ABSTRACT

Keywords:

• Cultivars
• heavy metals
• phytoremediation
• soil enzymes
• tannery sludge

Highlights

• Field experiment to assess the impact of tannery sludge amendments on soil enzymes activity and phytoremedial potential of two economically important cultivars of geranium.

• Urease and β-glucosidase activities were maximum at 50 tha⁻¹ TS application, whereas dehydrogenase and phosphatase activities were maximum at 100 tha⁻¹ in both cultivars.

• β-glucosidase, acid and alkaline phosphatase, urease and dehydrogenase activities were relatively high after 85 days over 45 days in both cultivars.

• Geranium was observed to be a good candidate for phytoremediation as it mitigates metal toxicity by root absorption.

• cv. Bourbon is better candidate for phytoremediation.

Acknowledgments

The authors are thankful to the Director, CIMAP, Lucknow, India, for providing the necessary facilities during the course of this investigation. Thanks are also due to CSIR, New Delhi for financial assistance through Network Project ‘INDEPTH’ along with Senior research fellowship and Academy of Scientific and Innovation Research (AcSIR), Anusandhan Bhawan, New Delhi, India.

Abbreviations

TS	=	tannery sludge
HM	=	heavy metals.

Conflict of interest statement

No conflict of interest is there in the present article.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

This work was supported by the Council for Scientific and Industrial Research [grant number BSC-0111].