Near-future L-band fully polarimetric Synthetic Aperture Radar (SAR) missions will provide meaningful and timely information over agricultural lands. In this paper, we evaluate the potential of L-band SAR polarimetry for crop monitoring using target decomposition theorems applied to full polarimetric imagery from NASA/JPL UAVSAR airborne system over a study site in Canada. Polarimetric parameters H, alpha0 and A are related to soil and vegetation water content, plant structure parameters (height and diameter) and the water distribution on the different plant parts (leaves, trunks, etc). Results are expected to contribute to the quantitative extraction of physical parameters over croplands.