The wet fields produce by far the greater part of the rice, and it is about them that most of the agricultural labors center.  In the broad valleys, low embankments, of sufficient height to maintain the water at a depth of two or three inches, separate the fields.  The lower plots are often of considerable length and width, some covering as much as an acre of ground, but as they begin to ascend the slopes, the walls rise higher, and the fields become narrower until they may be only a few feet in width.  In the rugged mountain districts, the terraces often begin just above the flood water of the stream.  At this point, a stone wall, four or five feet in height, is erected, and back of this the mountain side is cut away and filled in until it forms a step or terrace.  Back of this another wall is raised, and the process is repeated until at last the terraces extend for two or three hundred feet up the mountain side (Plate XLIX).  When the field is first made, top soil, enriched with vegetable growth, is laid on the surface, often to a depth of several inches, but from this time on no fertilizer, other than the decaying straw of the previous crop, is added, although the field is used continuously for many years.

Water is conducted to many of the fields by means of ditches, usually by diverting the flow of some of the numerous springs or streams but in a few instances, stone dams have been thrown across the rivers and the water carried for considerable distances by flumes and ditches.  The highest terraces are first inundated to the desired depth, and then openings are made in the side walls—­so as to allow the lower fields to be flooded.  This method of irrigation provides for the maximum use of the water, and also supplies a constant current which prevents the formation of stagnant pools.

Some of the fields are situated too far up the mountain side to be reached by ditches, and in such cases the growth of the rice is entirely dependent on the rainfall; however, in normal years, the precipitation is sufficient to mature the crop.

At the beginning of the rainy season, some of the seed rice is sprouted in specially prepared beds in the villages.  In such cases a small plot is surrounded with low dirt walls, the soil is enriched with manure, water is added, and the whole is worked until it becomes a thin mud, on which the rice is thickly sown.  Around this bed, a bamboo frame is erected to keep out pigs and chickens, while from time to time water is poured on the growing shoots.  The more common method of sprouting, however, is to select a piece of land, which will receive the full benefit of the rainfall and to break this with a plow drawn by a carabao.