Taylor et al. (2001) noted that well designed rotations are fundamental to organic farming systems. Rotations help organic systems achieve a balance between crops which deplete fertility, in particular nitrogen, and soil organic matter, and crops which restore fertility. The paper discusses the choice of crop rotation in the context of organic mixed farm systems that include cereals and livestock. The analysis is performed by combining economics and biology with the intention of capturing a broader approach to measuring the resilience of farming systems. Thus, it considers that the farmer’s choice of a specific rotation is based on the expected economic return derived from the rotation, and also the biological benefits provided by the selected rotation. The analysis is based on organic crop rotation trials ran from 1991 to 2006 at a site in the north-east of Scotland (Tulloch, Aberdeen) (Taylor et al., 2006).