Energy efficiency in a pear agroecosystem
The use of energy subsidies accelerates the flow of energy and the circulation of matter in agroecosystems which leads to an increase in entropy reflected in pollution and loss of biological-cultural diversity, among other aspects. In this context, energy evaluation of these systems could generate valuable information related to the energy balance used and extracted in the production process. The objective of the present work was to carry out an energy balance through the use of indicators in an organic and biodynamic pear agroecosystem. We analyzed the labor practices carried out during the productive season between August 2017 and February 2018 of a pear agroecosystem with organic and biodynamic management located in Patagonia, Argentina. A balance was made to assess the energy inputs and outputs expressed in megajoule per hectare (MJ ha‑1) and MJ kg‑1, allowing to calculate the total amount of energy needed to obtain the product. The energy indicators calculated were energy efficiency, specific energy and net energy. In this production system, 232.08 MJ ha‑1 of cultural biological energy and 16469.59 MJ ha‑1 of industrial energy were used, equivalent to 1.39 and 98.61%, respectively. With respect to the entry of indirect industrial cultural energy, a value of 68.12 MJ ha‑1 was observed, which implies a total energy income of 16769.79 MJ ha‑1. The values of energy efficiency, specific energy and net energy obtained by the evaluated agroecosystem were 3.08, 0.79 MJ kg‑1 and 34538.33 MJ ha‑1, respectively. Results reflect a high dependence on subsidies. Analyzing systems through the energy flow is a relevant aspect to promote sustainable agroecosystems.
Dussi, M.C., Fernández, C., Machuca, Y. and Flores, L. (2021). Energy efficiency in a pear agroecosystem. Acta Hortic. 1303, 419-426
agroecology, energy flux, organic and biodynamic production, Pyrus communis, sustainability