The mountain terraces in the cordilleras of northern Luzon, Philippines, were included in the UNESCO World Heritage Sites list in 1995. Propitiously, there was no mention of the word rice in the citation of the inclusion. It well may be because, when the Spanish explorers went up the cordilleras in the 16th-17th centuries, they made mention of the existence of terracing. However, no mention of rice was made.
There are two known methods of cultivation in Ifugao land. One of these is the universal slash and burn gardening method also known as swiddening while the other method grew out of this early technology with the dry field cultivation or taro (Colocasia esculenta). This transpired because some varieties of taro are grown in wet areas in catch basins along mountain streams. The elderly Ifugao preferred these varieties. This type of taro cultivation, both dry and wet, can still be seen in the southern cordillera ranges, especially in the province of Nueva Vizcaya, among the I’Wak and Ikalahan peoples. The Ikalahan are the same group as the Kalanguya, which is one of the subgroups of Ifugao that live in the southern part of the province. The people known as Ifugao are actually not only one group but made up of several. There are two major groups: the Tuwali, and the Ayangan. A third group exists called the Kalanguya, whose language is somewhat different. Originally, the staple of the Ifugao people were root crops, taro being one of the oldest and the one most relevant in their rituals, even having a ritualistic name. Rice came much later and became a hugely prestige crop.
The earliest evidence for the existence of rice in the Philippines is between 2510 and 2130 BC, dated by finding the husk of rice embedded in pottery excavated from the Manga site in Andarayan located in the Cagayan Province. Rice is a crop harvested in the lowlands since it requires flooding to grow. Another peculiarity is that it needs to adapt to higher elevations. This is the reason that the yield of rice diminishes as the elevation of the fields go higher. The agricultural technology of rice in Ifugao is basically adapted to the lowland of the mountain terraces, with some forms of adaptation that must have taken a great deal of time to develop.
As early as 1545 to 1000 BC in the present town of Banaue, there is evidence of residential occupation in the area. By the seventh century, through the time period between 1195 to 1380 AD in Bungahalian and Nabyun, respectively, the presence of terraces have been reported, but between 1486-1788 AD in Bocos, Banaue, there was definitely a rapid expansion of terraces with the rise of rice cultivation.
The Ifugao terraces are not actually carved out of the mountain side, rather, these are stone or earth walls which have been developed slowly by geological means; as the space between the wall and the mountain side fills up with different layers of rubble, grades of soil and water impervious clay beneath layers of organic soil to present water loss in the paddy fields thus created. The above the system of terraces also have forests to serve as watersheds from which irrigation ditches are constructed from field to field, which allows the water to drain off to rivers below. The terraces are fragile in construction so much that no draft animal, like the carabao, can be used to plow the field. Instead the soil is cultivated by hand using wooden spades. Rice is planted at the beginning of the year and harvested around June, opposite to methods of lowland rice cultivation.
The fragileness of the environment and the human agricultural technology is reflected in the Ifugao cultural attempts to control it through means of numerous rituals they associated with cultivation, of which, for rice alone there are at least twenty-two. This is not surprising since, the Ifugao traditional religion has a pantheon of deities numbering at least two thousand.