Tendencias en el uso de la tierra y diversidad productiva en establecimientos agropecuarios del centro-sur de la provincia de Buenos Aires (Argentina)

benito juarez county, in the central-south buenos aires province (argentina), is environmentally and productively heterogeneous, with predominance of cattle farming. in order to evaluate the tendencies in land use, the evolution of different productive items and their diversity throughout the period 1998- 2007 were described on the basis of 30 farms selected. the grasslands occupied the greater proportion of the area throughout the period studied, but they reflected a loss of 23 percentage points which was only partially compensated by an increase of perennial pastures. this fact caused a decrease in the area destined to cattle raising which at the end of the period was slightly surpassed by the area destined to annual crops. among the latter, soybean was the crop with greater expansion but its relative participation reached only 11.02%. simultaneously, productive diversity, estimated by an adaptation of shannon′s diversity index, increased 30.84%. although the advance of annual crops to the detriment of grasslands is evident, the partial replacement of the latter for perennial pastures and the increase in productive diversity limit the potential environmental risks revealed in other regions of the country.