Evaluación de la sostenibilidad energética en un agroecosistema lechero convencional

Abstract

Objective: To evaluate the energy sustainability of milk production in a conventional agroecosystem. Materials and Methods: The system diagram was designed according to the energy flows involved in the productions of two consecutive years. The energy invested in obtaining the materials and services used to produce milk was determined and the traditional and modified energy performance indexes were calculated and interpreted: transformity, renewability, energy yield ratio, energy investment ratio, environmental load ratio and sustainability index. Economic indicators were determined: net income, total costs, gross profit and profit/cost ratio. Results: The energy indicators showed that under the current production model the agroecosystem is unsustainable (0,9) over time. High energy costs (2,98 E+06 and 3,28 E+06 seJ/J), low support from renewable sources (33,8 and 38,5 %), adequate potential to produce primary energy (1,51 and 1,63), high dependence on external resources (1,96 and 1,60) and low environmental impact (1,96 and 1,60) were recorded. However, the classical economic analysis showed profitability of the system (2,12 and 1,80 CUP). Conclusions: The energy indicators expressed the inability of the agroecosystem to sustain itself over time under a conventional design of production. The classical economic analysis demonstrated the profitability of the agroecosystem; while the energy synthesis evaluation indicated that it is unsustainable.

Keywords

• economic analysis
• energy
• milk production