To better predict the long-term fate of soil organic carbon, we seek to understand the transformation of crop residue components into recalcitrant components of soil organic matter. We characterize both aboveground and belowground crop residues as well as soil organic matter by using Fourier-transform infrared spectroscopy and advanced solid-state nuclear magnetic resonance spectroscopy. These analytical approaches are supported by elemental analysis and thermal analysis. In this presentation, we describe the use of multiple techniques to test the hypothesis that the accumulation of recalcitrant components in soil organic matter is regulated by landscape position and drainage class.