ASSESSMENT OF SOIL CARBON STOCK UNDER ARECANUT AND COCONUT PLANTATIONS IN KARNATAKA
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Date
2018-12-10
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
UNIVERSITY OF AGRICULTURAL SCIENCES, GKVK BENGALURU
Abstract
A study was undertaken across different agro-climatic zones (ACZ) of Karnataka,
with an objective to assess the vertical distribution of soil carbon stock in coconut and
arecanut plantations. The higher soil carbon stock was found in arecanut (2.71 kg m-2
) as
compared to coconut (2.32 kg m-2
) plantations. Significantly higher soil carbon stock was
observed in hilly zone (3.25 kg m-2
) followed by southern transitional zone (2.52 kg m-2
),
coastal zone (2.51 kg m-2
), southern dry zone (2.3 kg m-2
), and eastern dry zone (1.96 kg
m-2
). Irrespective of crops and zones, arecanut soils had higher carbon content than
coconut soils. The pooled data revealed that surface (0-30 cm) soil depth had 35.7 and
36.4 per cent higher carbon stock in arecanut and coconut, respectively as compared to
sub-surface soil depth. In sub-surface soil (30-120 cm), 64.3 and 63.6 per cent soil carbon
stock was noticed in arecanut and coconut, respectively. Significantly (p<0.05) higher
soil carbon stock was recorded within 0–30 cm (3.63 kg m-2
) soil depth and it was found
to decline with depth. The interaction effect between crops, zones and depths was found
to be significant. However, zone and depth (Z×D) crop and depth (C×D), crop and zone
(C×Z), crop zone and depth (C×Z×D) for soil organic carbon in coconut and arecanut
crops across different ACZ was found to be non-significant. Significant difference was
observed for dehydrogenase (DHA), alkaline phosphatase (ALP) and acid phosphatase
(ACP) in arecanut and coconut soils but no difference was observed for available N, P2O5
and K2O. A significant positive correlation was observed for different carbon pools with
pH, clay, CEC, available N, P2O5 and K2O, DHA, ALP and ACP activity and negative
correlation with sand and bulk density of soil. In general low management attained less
soil carbon status in whole soil profile (0-120 cm) than the highlevel management in both
crops representing all agro climatic zones.
Key words; Soil carbon stock, Agro-climatic zones, Coconut, Arecanut, carbon pools