ABSTRACT - Crop rotation is one of the oldest management strategies in agriculture and has two main purposes:plant nutrition and management of weeds, pests, and diseases, particularly soilborne diseases. Not only is it a long-term strategy for organic agriculture, it is a strong recommendation and a requirement in some countries. One of the consequences of crop rotation in farming systems is the mosaic of crops at farm and landscape levels. With an increasing number of crops in a rotation, the fields on a particular farm usually become smaller. This increases the agrobiodiversity at the landscape level. The size and complexity of the mosaics in space and time have a tremendous influence on the development of plant disease epidemics and pests. Here, we focus on the temporal variation in crops and its consequences for plant disease development. The succession of a variety of crops can affect both foliar and root diseases. The effects on foliar diseases are, however, primarily determined by the spatial pattern in crops, especially when pathogen inoculum is spread over medium or large distances. We limit this chapter to effects on soilborne pathogens with local inoculum spread; this includes splash-dispersed soilborne pathogens that affect the lower stem and foliage as well as root-infecting pathogens.