Exploring the sustainable horticulture productions systems using the emergy assessment to restore the regional sustainability

This paper shows the environmental behavior of different horticultural production systems. Emergy assessment was applied for the analysis of three family-managed horticultural farms located in Ibiúna County and one horticultural subsystem of Yamaguishi Eco-Village in Jaguariúna County, both located in the state of São Paulo, Brazil. For Ibiúna and Jaguariúna farms the total Emergy varied from 2.36E+16 to 9.59E+16 seJ ha−1 year−1, the Transformity ranged from 1.58E+06 to 4.98E+06 seJ J−1, the Renewability from 17% to 55%, the Emergy Yield Ratio from 1.14 to 2.24 and the Emergy Investment Ratio ranged from 0.81 to 4.76. The Environmental Loading Ratio values showed a large variation, for organic production from 0.81 to 1.54 and for the conventional production from 4.77 to 4.88. Emergy Exchange Ratio showed a wide variation from 0.03 to 3.49. These results were compared to those obtained in an emergy analysis of five organic horticultural systems located in the highlands of Rio de Janeiro, a study performed by Nobre Junior (2009). The analysis of the whole set of results is that the renewability of Rio de Janeiro's systems is higher than Ibiúna and Jaguariúna systems because these last systems respond to the pressures of market to decrease prices increasing the volume of production using industrial aggressive inputs in a more intensive way. The conclusion will be made available to Ibiúna city government and population in order to promote a transition to Agroecological Systems involving the recovery of soil biota and native vegetation, recycling urban wastes and lowering pesticides and chemical fertilizers use.