This article analyses the functioning of agricultural systems based on organic energy in contrast with the present situation. To accomplish it, an example has been taken from the mid-18th and 19th centuries in the Southern Iberian Peninsula (Santa Fe), before the spread of chemical fertilizers. The analysis is centred on energy flows and looks at territorial changes occurred in the system at that time. In order to show the contrast, recent data (1997) has also been included in some 01 the tables. The structure, functioning and organization of both agrarian systems is different, showing distinct scales in both forms of production together with environmental Iimits where established. The conventional measuring instruments are designed in such a way that favour, given their plot focus, those farmers that manage to maximise the relation between soil, nutrition, and plant, subordinating the whole agricultural system to this aim and subsidizing it with energy and external nutrients.