This paper discusses the possibility that heating of the solar corona in open field-line regions emanating from coronal holes is due to a nonlinear cascade, driven by low-frequency or quasi-static magnetohydrodynamic fluctuations. Reflection from coronal inhomogeneities plays an important role in sustaining the cascade. Physical and observational constraints are discussed. Kinetic processes that convert cascaded energy into heat must occur in regions of turbulent small-scale reconnection, and may be similar in some respects to ion heating due to intense electron beams observed in the aurora.