Environmental management of the Ifugao rice terraces in Kiangan and Banaue, Philippines

The results of the study established that the Rice Terraces were in fact being degraded. This process was not limited alone to the destruction of terrace dikes, but also extended to changes in the chemical properties of the soil, as well as the social and economic values of the terraces. The destruction of dikes in Bocos [Banaue, Philippines] were nine times higher than in Nagacadan. Since the catchment or muyung of the terraces in both sites were still in good condition, water and nutrient flow toward the rice terraces remained normal. The primary destructive agent was perceived to be an extraordinary species of earthworm, although insect like crickets and ants may have also contributed to some extent. The earthworm, which is much longer than the ordinary earthworm species, burrows in dikes and exists in higher population density in Bocos than in Nagacadan [Banaue, Philippines]. In Bocos, the soil is moderately acidic and contains much higher organic matter - the two conditions favorable to earthworms. In contrast, the soil in Nagacadan is strongly acidic and the organic matter is lower - conditions which were not favorable to earthworms. These soil conditions may have been brought about by the change in land use. Nagacadan farmers, responding to government policies promoting crop diversification and programs of other agencies like CECAP [Central Cordillera Agricultural Programme], introduced high yielding varieties of rice (HYVs), vegetable crops, and extensively applied fertilizers and pesticides. These patches of HYVs and vegetable crop species on the landscape of the rice terraces may have degraded the aesthetic value of traditional rice in the Rice Terraces. On the other hand, Bocos farming remains traditional. The community has resisted modernizing their agriculture. As a result, the aesthetic value of the landscape is preserved, thus more tourist visit the place every year. The effect of earthworms or dikes may be further aggravated by water supply, typhoons with strong winds, and the earthquake that occurred ten years ago, which may have destabilized the terrace slopes