Distribution Of Soil Organic Carbon Of Selected Land Use Types In Federal University Of Agriculture, Abeokuta, Ogun State, Nigeria
Oladoye, A. O., Ojekunle O. O., Oyebamiji, N, A. and Olusola A. O (2020): Nigerian Journal of Forestry, 50 (1) 43-51
The contributions of soil to tree growth are very significant and it stores more carbon than the atmosphere and terrestrial vegetation together. The effects of land-use on the Soil Organic Carbon (SOC) in different land use types were examined in this study. The soil samples were collected at two depths (0-30cm and 30-60cm) from four sites namely; Gmelina arborea, Tectona grandis, Leucaena leucocephana plantations and secondary natural forest. The samples were analyzed for Soil Organic Carbon (SOC), Labile Organic Carbon (LOC), Microbial Biomass Carbon (MBC) and Dissolved Organic Carbon (DOC). The data were subjected to one-way Analysis of Variance and Duncan’s Multiple Range Test was adopted for the separation of means at 5% level of probability. The result shows that there were significant differences in the distribution of soil organic carbon between depths. At depth 0-30cm, highest SOC (8.59±0.55) and MBC (6.97±0.47) were recorded while the least values were obtained for LOC and DOC. With respect to land use types, there were significant differences in SOC, LOC, DOC and MBC (P<0.05), the highest SOC (10.04±0.10) was recorded in Leucaena plantation at 0-30cm, followed by (9.64±0.63) in secondary forest at depth 0-30cm. However, the least SOC was recorded in Tectona grandis plantation (4.09±0.08) at depth 30-60cm. Highest LOC (12.91±0.20) was recorded in Leucaena plantation at depth 30-60cm while the least (6.59±0.07) at depth 0-30cm. was recorded in Tectona plantation. The highest DOC recorded was (11.81±0.05) in Secondary forest at depth 30-60cm while the least was obtained in Tectona plantation (6.75±0.08) at depth 0-30cm. Highest MBC (8.20±0.00) at depth 0-30cm in Secondary forest while the least (2.91±0.01) was recorded at depth 30-60cm in Tectona plantation. The high DOC in the secondary forest could be a reflection of the high level of species diversity and the high level of SOC in Leucaena may be due to the abilities of the species which tend to increase SOC storage in long term. The study inferred that soil organic carbon and its fractions showed a significant spatial variation among the sites examined.