Resumen

NASCA, José A; TORANZOS, Manuela  y  BANEGAS, Natalia R. Evaluation of the sustainability of two cattle models in the depressed saline plain of Tucumán, Argentina. Zootecnia Trop. [online]. 2006, vol.24, n.2, pp.121-136. ISSN 0798-7269.

The sustainability of two physical cattle models of the depressed plain saline of Tucumán (area of probable cattle expansion) was evaluated in relation to environmental, economic, and social indicators. Work was done, during 3 years, with two physical models based in pasture (Chloris gayana cv Finecut) of young fattening steers with similar stocking rate: T0 = traditional continuous-grazing (preponderant zonal situation), and T1 = controlled grazing system with strategic supplementation. Given the farm scale of the experience, priority environmental indicators were selected: 1) Environmental:  cattle production, Chloris cover, weeds, litter, bare ground,  soil organic matter, CH₄ estimate, risk of use of fossil energy; 2) Economic: gross margin of the activity, and 3) Social: technical responsibility. The methodology was based on the determination of the sustainability index (SI).  Local values were taken as thresholds, plus a 20% as demand of improvement or bibliographical information.  The SI were calculated as the relation between the indicator value and the threshold value.  The system will be sustainable if the average of the SI is equal or greater than one, being one the limit of sustainability.  In T0 with a SI of 0.58, seven of the selected indicators did not reach the limit, being methane estimation and Chloris cover particularly lower.  In T1, with application of input technology and process, all the indicators surpassed the sustainability limit, being SI of 1.55.  This model would be a feasible alternative for a sustainable cattle development of the depressed plain saline of Tucumán, obtaining young steers from weaning to task in 10 to 12 months.

Palabras clave : farm sustainability; environmental indicators; production systems.