Mixed farming systems occur on different levels and at different intensities and in many different forms. They can be defined according to different components, i.e. on-farm, between farms, between crops, between animals and crops and, as in this document, in particular as crop-livestock systems. Even the crop-livestock systems occur in different modes, depending on the access of farmers to land, labour and capital. Individual farmers will feel no incentive towards mixed crop-livestock farming if either cropping or raising livestock is impossible due to factors such as unreliable rainfall, low soil fertility or presence of particular pests and diseases. Farmers will also not be inclined to apply mixed farming when conditions favour specialization but they can become interested in mixed crop-livestock farming when mixing helps to overcome local problems of soil fertility, resource-depletion or waste-disposal. Mixed farming is not just a thing of the past; modern high-input systems can also learn a lot from the older mixed systems, both in terms of methods of integrating crops and livestock, as well as in terms of obtaining new ways of looking at agricultural productivity. The issue of the communal ideotype is particularly important where components of the farm need to be mutually adjusted. A high yield of the total system is to set the limit of the yield of the components. In that same sense, a lower yield of components may give a higher yield of the total. Highlighting these issues may not only serve to achieve a new approach to farming but may also set an example for other sectors of society.