• Energy Research
• 15. Life on land close
• ES close
• Spanish; Castilian close

On the one hand, this article reviews the works presented on energetic analysis of Spanish agrarian systems since the 80's and, at the same time, we emphasize the originality and validity of those texts. On the other hand, we update to 2000 the estimates of the energy balance tor Spanish agriculture as a whole showing how the loss of energetic efficiency of agriculture has increased in the 90s. As a result of it, we have an agriculture with a growing and continuous dependence 01 energy, and not only due to the increasing use of machinery and fertilizers, but also because 01 the growing energy demand supported by electricity and petroleum, and related to the indiscriminate extension of the irrigable land with independence of the hydrological conditions of the territory.

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.

La evaluación de la sostenibilidad en modelos de producción porcina en Cataluña (España), mediante el análisis multicriterio, se estructura en dos partes. Una primera de establecimiento del marco de análisis donde, de forma participativa, se fijan los criterios de evaluación, sus indicadores y las escalas de evaluación. En la segunda se implementa la metología expuesta para evaluar la sostenibilidad de tres modelos productivos y detectar posibles conflictos entre los diferentes grupos de interés. Los resultados obtenidos demuestran que desde el punto de vista de la sostenbilidad, en base a los criterios considerados y bajo distintas opciones de robustez, el modelo productivo más sostenible es el ecológico, seguido del familiar y, en último puesto, el del modelo denominado de integración. En cuanto a la formación de coaliciones se observa que hay un importante grupo de actores que apuestan, en primer lugar, por el modelo de integración. Los anteriores resultados avalan la necesidad de potenciar modelos intermedios entre el ecológico y el de integración. Una opción conciliadora, entre las existentes, podría ser el tipo familiar, aplicando algunas mejoras en el manejo si se quieren satisfacer plenamente los requerimientos de sostenibilidad. The sustainability evaluation of pig production systems in Catalonia (Spain) based on multicriteria analysis is divided in two parts. The first part shows the framework of the analysis and the established criteria for the evaluation. The second part applies the developed methodology in order to evaluate the sustainability of three productive systems and also, to find points of conflict between actors and the different options for their understanding. The results show the ecological system as the more sustainable, the second position is for the traditional family farming system and the last one is the integrated system. Nevertheless, a great part of actors supports integrated system. These results indicate the need to find alternative models between the ecological and the integrated ones. The improved family system could be an option in order to fully satisfy sustainable requirements.