Balance de energía en cultivos hortícolas a campo en Rosario (Santa Fe, Argentina)

the energy management in potato, tomato and lettuce production systems was analyzed in an area close to the city of rosario (argentina). all the material inputs and the yields were considered and transformed into energy units by means of multiplying the quantity of material by their energy contents. the direct as well as the indirect energy were analyzed. for the energy management, the physical limits of the system were considered. the indicators used were energy efficiency (efe) and energy productivity (ep). the potato and tomato crops energy balances were negative while the energy output of the lettuce crop was lower than its input. tomato crop showed the best energy efficiency (3.54) followed by potato crop (2.69). energy efficiency was the least (0.25) in lettuce crop. moreover, energy input in the tomato production was the most efficient (88.6 kgms/100 mj), followed by the potato (16 kgms/100 mj) and the lettuce (10.8 kgms/100 mj).