CARBON DYNAMICS OF RECLAIMED COAL MINE SOIL: A CHRONOSEQUENCE STUDY IN
THE GEVRA MINING AREA, KORBA, CHHATTISGARH, INDIA
Abstract
Reclamation of mined soil improved soil quality and SOC sequestration. A
chronosequence study consisting of 8 and 25years old reclaimed mine
soils under Azadirachta indica, Gmelina arborea, Dalbergia sissoo and
recently dumped soils in Gevra, Chhattisgarh, India was initiated to
quantify the quality and quantity of carbon pools. MBC (microbial
biomass carbon) showed highest value in case of Azadirachta indica
(1468.45 ug C/g soil) followed by Dalbergia sissoo (1338.19 ug C/g soil)
and Gmelina arborea (1160.61ug C/g soil) in surface soil after 25years
of reclamation. Mean total soil C stock was estimated as 334.72,226.94
and 191.20 Mg C ha-1, under Azadirachta indicia, Dalbergia sissoo and
Gmelina arborea plantation respectively. Carbon stock of the soil
increased with an increase in year of reclamation. Among the four
different pools of organic carbon, the carbon per cent was highest in
the non-labile pool of carbon under Azadirachta indica (88.25%). Humic
acid C content and C/N ratio had increased under Azadirachta indica,
Dalbergia sissoo with an increase in the year of reclamation. FT-IR
spectra in the case of Azadirachta indica, Dalbergia sissoo and Gmelina
arborea indicated that relative proportions of aromatic groups along the
chronosequence have increased. TOC (Total organic carbon) content was
highest under Azardichta indica but aromaticity was highest under
Gmelina arborea as obtained by E4/E6 and EET: EBZ ratio. These results
indicated that different carbon pool and aromaticity of carbon improved
with the increase in year of reclamation and significant relationships
were present between spectroscopic indices and different soil carbon
parameters.