Despite the possible mitigation of carbon emissions by favoring carbon transfer to terrestrial carbon sinks, little is known about the capacity of different crop genotypes to enhance soil carbon sequestration. We hypothesize that carbon sequestration potential linked to old wheat varieties (released before 1960) is higher than the one linked to modern ones while old varieties are known to develop bigger and deeper root systems. Moreover, modern varieties are often cultivated using synthetic chemical inputs known to modify soil carbon dynamics. We conducted a field experiment by cultivating four modern and four old wheat varieties, with and without chemical inputs (nitrogen, herbicide and fungicide), in Calcaric Cambisol conditions. After root and soil sampling, root morphology was assessed by image analysis, whereas potential catabolic activities by soil microbial communities was assessed by MicroResp ™ measurements. Additionally, CO2 emissions measurements were done by incubating soil and roots from each agronomic modality. Results suggest that the genotype (old versus modern varieties) did not affect root traits nor substrates respiration, but the soil from old variety modalities released 6% more CO2 than the one from modern ones. Application of inputs did not affect root traits, but increased soil microbial respiration by 11%. Inputs also increased the respiration of citric acid by 19.1%, while it decreased respiration of fructose and alanine by 8.84% and 16.79%, respectively. Taken together, our results invalidate the hypothesis that old varieties could be more performant than modern ones in storing carbon in this specific soil.