There are controversies about findings on the effects of tillage practices and soil amendments soil organic carbon storage. Hence, a 3-year study was conducted at an Agricultural Research Station of the Kwame Nkrumah University of Science and Technology (KNUST), Anwomaso, to investigate how tillage and soil amendment influence carbon sequestration on a benchmark soil in Ghana. Split-plot design with three replications was used. Four tillage practices (main plot factors); no-till (NT), hoe tillage (H), plough plant (PP) and plough and harrow tillage (PH); and four soil amendments (sub plot factor); 3 t/ha poultry manure (PM), 60-40-40 NPK (NPK), 1.5 t/ha poultry manure plus 30-20-20 NPK (½ R) and no amendment (NA) were used. Soil samples were taken from the topsoil (0-15 cm) and subsoil (15-30 cm) depths. Carbon stocks within fractionated soil aggregates was estimated. The carbon stocks per aggregate fraction was significantly different, in a decreasing order of LM (large macroaggregates) > SM (small macroaggregates) > mM (microaggregates) > S+C (Silt and clay fraction) at the topsoil and SM > LM > mM > S+C at the subsoil. Tillage effect on carbon stocks (summing organic carbon stocks within aggregate fractions) was significantly highest under NT (45.31 t C/ha) at the topsoil and under PP (31.38 t C/ha) at the subsoil. The most stable soil carbon stock which occurs in the microaggregate fraction (0.053 – 0.250 mm), according to research, was highest PP (18.12 t C/ha) and was significantly different from NT (15.69 t C/ha), H (15.51 t C/ha) and PH (12.12 t C/ha) at both sampling depth. Soil amendment did not have significant effect on carbon stocks within the various soil aggregates. The tillage-soil amendment interactive effect on carbon storage in microaggregates was highest in PP/PM and was significantly higher than all other combinations except PP/NPK and PP/½ R. The study revealed potential storage of stable organic carbon under PP tillage and PP/Pm interaction

Keywords: carbon storage, soil fractionation, tillage, tillage and soil amendment interaction