Switchgrass (Panicum virgatum L.) is a monocot C4 perennial grass native to North America. Switchgrass has been identified as a “model” herbaceous species for bioenergy production by the U. S. Department of Energy. Besides the gains in reduced GHG emissions from switchgrass-sourced bioethanol, an aspect which is of particular importance is soil C sequestration: it appears pivotal to explore the possibility of plant breeding for improved carbon sequestration capacity. The present work focuses on the ability to increase soil C storage of 150 different switchgrass genotypes in response to water-stressed conditions by measuring yield and testing Permanganate Oxidizable Carbon (POXC) content at 0- to 15, 15- to 30 and 30- to 60 cm. The overall objectives are to evaluate the variability in C sequestration over time, also in response to water limitation conditions, to investigate the relationship between C sequestration and yield, and to evaluate drought tolerance within a diverse panel of switchgrass genotypes over multiple growing seasons. We found statistically significant differences in average POXC content between different depths and treatments. POXC was lower at deeper soil layers and under the drought treatment. In addition, there was no correlation between yield and POXC within the control plot, whereas we found a slightly positive, significant correlation (p<.001) between yield and POXC under the drought treatment. In order to evaluate drought tolerance among the 150 genotypes involved, we calculated a drought adaptation index (DAI) for POXC and yield in both 2021 and 2022. We were able to identify four genotypes that consistently performed above average.This study provides rich background information on aboveground and belowground performance of Switchgrass as a potential biofuel crop, contributing to the evaluation of the sustainability of biomass-sourced bioethanol. The genotypes identified may be subject of further research on the biology of their drought tolerance and soil-rootstock interactions.