e demonstrated by a comparison of the figures for energy use against rice production. According to Pimintel and Pimintel (1991), rice production by the Iban tribe is a typical example of manpower production, and a comparison of the rice production of the Iban with other rice producing nations and systems is informative. The energy inputs for a hectare of rice total 1.0 x 106 Kcal for the Iban, with about 2/3rds of this expended for manpower labor and the other 1/3rd for seeds. The yield is about 2020 kg ha-6 or about 7.3 x 106 kcal food energy, which makes the output/input ratio 7:1, this denotes a relatively high return for the investment.
Rice production in other parts of the world shows a number of differences based on the method of production. Some rice producers make greater use of animal power along with manpower, as in the Philippines. There, the total energy inputs are 1.8 x 106 kcal to produce about 1650 kg of rice, with the equivalent of 6.0 x 106 kcal food energy. The output/input ratio is then 3:1, about half that for Iban rice production.
Rice production in the United States, on the other hand, requires large inputs of energy, particularly energy from fossil fuels. In California, for instance, the average yield of 6160 kg ha-1 (22.4 x 106 kcal) is significantly greater than in other systems, and the high energy input of 14.4 x 106 kcal results in a low 1.6:1 output/input ratio.
Rice production in Japan is still relatively labor-intensive and requires about 1730 hours of manpower per hectare. The rice yields in Japan are lower, but the fossil energy inputs are also lower than in the United States, resulting in an output/input ratio of 2.5:1. This indicates that the Japanese have a more efficient system. The Iban system is still more efficient than either that of the U.S. or Japan, though.
The subsistence agriculture of the Iban is based entirely on the cultivation of hill rice. Each year every bilek...