An energy-based analysis of organic, low external input sustainable agriculture (LEISA) and conventional rice production in the Philippines

In a comparative study of energy use in three farm systems, organic farming was found to be the most energy efficient because it utilized the least amount of energy. One (1) ton of unmilled rice used only 277 Mcal in organic farming, 501 Mcal in low external input sustainable agriculture (LEISA) and 837 Mcal in conventional farming. The total energy input in the organic rice farms was only 37% (1,045 Mcal ha(-1)) of the total energy input in the conventional farms (2,848 Mcal. ha-1). Total energy input in LEISA was moderate at 1,773 Mcal ha-1. The application of chemical fertilizers and pesticides explains the high energy inputs in conventional farming as they accounted for 80% of the fossil-fuel-based energy inputs (FFEI) and 70% of the total energy inputs (TEI). Energy efficiency (Ee) was 21.53 and 11.95 for FFEI and TEI, respectively, in organic farming while it was 8.91 (Ee (FFEI)) and 6.63 (Ee (TEI)), respectively, for LEISA. In the conventional farms, Ee (FFEI) was only 4.93 and Ee (TEI) was 3.45. Non-use of any agrochemical inputs in organic farming made it four times more energy efficient than conventional farming and twice more efficient than LEISA. Organic rice farming was not only energy efficient, it was also found to be equally or slightly more productive. Unmilled rice yield Was 3.81, 3.58, 3.25 ton ha(-1) in organic, LEISA and conventional farms, respectively.