The correlation between total organic carbon (TOC), organic matter and water content in soil collected from different land use of Kota Bharu, Kelantan

A total of twenty three sites distributed in different land uses of Kota Bharu, Kelantan was
identified for the study. The relation of soil organic matter (SOM) content, total organic carbon (TOC)
content, water content and soils texture for industrial area at Pengkalan Chepa, southwest (SW) of
Kota Bharu district as a township and agricultural area at Banggu were investigated. These data sets
were also correlated to temporal event in Kota Bharu district. Correlation analysis indicated that,
generally, SOM and TOC concentration and water content had a positive correlation with clay and
silt but negative correlation with sand. The relationships between SOM content, TOC content and clay
+ silt content, were also studied. The results showed that, SOM concentration was lower (P < 0.05)
at Pengkalan Chepa area (3.41%) compared to SW Kota Bharu (5.14%) and Banggu (4.94%). At the
same time, the TOC level also showed that Pengkalan Chepa area recorded the lowest concentration
(0.90%) followed by SW Kota Bharu (1.02%) and Banggu (1.43%). The same trend was discovered
for clay + silt content where the lowest concentration was recorded in Pengkalan Chepa (8.44%) and
it was followed by SW Kota Bharu (34.25%) and Banggu (51.77%). The SOM was positively
correlated with the TOC and clay + silt in all the study areas. The percentage of TOC in the soil
samples from the study area ranged from 0.48wt% to 2.58wt%, with a mean of 1.40wt%, and the
percentage of SOM, from 1.52wt% to 11.85wt% with a mean of 5.45wt%. The low TOC and SOM
content in the soil was believed to be due to the low vegetation cover which led to the soil clay
fraction mineralogy.