Crop rotation has been known for many years as an effective strategy for controlling weeds because it has a disruptive effect on weed populations. Cover crops are important additions to cash crop rotations because they suppress weeds during rotational periods when crops are absent and provide ecosystem services that enhance soil quality and fertility. This chapter describes current research on crop phenological diversity and management disturbance diversity, before suggesting new analytical frameworks for assessing the multifunctional properties and overall sustainability of cover crops and crop rotations. The chapter looks forward to future developments in this area and provides suggestions for further reading on the subject.