Sustainability evaluation of long term organic farm systems

The paper deals with the evaluation of sustainability at farm level in a long term experimental farm organically managed since 1992 in Tuscany. The aim was to develop and implement a multi-objective organic agriculture, to establish new concepts of farming as result of long term research analysis and to provide a practical and easy understanding on what is necessary to change or improve in farming management. Soil fertility and biodiversity indicators are taken into consideration in the period 1992-2006: the weak points and the improvement obtained by the farm management are underlined. The values of indicators changed rapidly towards the desired ones in the first 6 years period. After 13 years, in 2005-2006, the situation appear almost stable, P balance is still a problem, some little discrepancies for C/N ratio and KAR indicate the need to re-examine some of the production methods.