Comparative analysis of biomass flow in conventional and organic sugarcane production systems: net primary production energy quantification from the agro-ecological perspective

The present study is based on Agroecology principles and follows the theoretical-methodological approach of Social Agrarian Metabolism to find the sustainability biophysical perception in two sugarcane production systems, in Pernambuco State, Brazil, namely: organic and conventional. Data were collected through interviews and subjected to a set of calculations carried out in converters to quantify biomass and energy net primary productivity (NPP) in the two production systems. NPP biomass was decomposed and classified, and it allowed knowing its flow in both production systems. The conventional system recorded a larger amount of socialized biomass and energy, but the organic system accounted for higher total productivity, as well as for proportionally more balanced partition between different biomass and energy categories. The conventional system was energy exporter, and the organic system was energy conservationist. Although the two systems are based on sugarcane monoculture, with biodiversity limitations, the organic system proved to be more sustainable from an agro-ecological viewpoint, since it does not depend on burns, chemical (synthetic) fertilizers and pesticides, and provided biomass and energy to heterotrophic organisms, as well as acted in maintaining background elements and contributed to improve ecosystem services.