Adversities of climate change related with GHG’s emissions emphasize the importance of carbon sequestration in the terrestrial system. The Soil, is a major terrestrial sink emphasize the research needs to quantify its potentiality. Variability in topography, land use and farm types can influence the bio-physical properties of the soil thereby affecting the carbon storage potential.
The research was conducted in Butaeibega village, Bukoba district of Northwest Tanzania near to the Victoria Lake. Soil samples were collected from three depths of different fields under different land use across different topographic positions. An attempt was done to classify farms based on socio-economic criteria to evaluate the current carbon stock and the potential to store carbon. The representative profile study and bulk density measurement were taken to quantify the soil carbon stock across all the topography. The potential or attainable carbon sequestration based on soil texture was calculated for all the land uses and a dynamic simulation model was used to simulate different management scenarios for 10 years to estimate the potential soil carbon stock in the top soil of annual cropping fields.
The results showed that the clay + silt of the soil do not significantly vary along different land uses. However, the soil carbon concentration significantly differs between the home garden and other land uses. This significance was found within all the topographic classes. The soil carbon concentration in the home gardens belong to top topography was significantly different from the mid valley and valley bottom topography class. The crops and management in different land uses in different farm types was similar except in the home garden. The maximum carbon stock that can be sequestered in top 30 cm of soil profile was estimated to be 90t ha-1.
The simulation results showed that the incorporation of residue and cattle manure increases the soil organic carbon buildup and saturation can be reached by adopting specific management continuously for 10 years. Soil textural property of Bukoba soils shows the potential to store carbon still exists before the saturation level. However, the feasibility of these management scenarios has to be studied before implementing under CDM projects.