Erosion

In increasingly large areas, erosion exacerbates water shortages. On Buguias's eastern slopes, many small streams are entrenching, making water delivery even with hoses ever more difficult. Near Asinan Creek the problem is compounded: as the stream has cut downward the salt spring has migrated headward, forcing gardeners to extend their hoses ever further upstream to find fresh water.

Topsoil loss more directly threatens many gardens. Scattered throughout Benguet are former vegetable fields now abandoned for lack of soil (Dar 1985:136). Typhoon-generated erosion, taking the forms of sheet wash, gullying, and slope failure, can be extraordinary. Terracing mitigates the danger, but even the best-engineered terraces occasionally fail. Moreover, most farmers purposefully keep some fields sloped for wet-season drainage. And landslides, slumps, and debris flows may strike regardless of agricultural engineering; a massive flow in central Buguias in the late 1960s devastated several tens of hectares both in its source area and in its deposition zone. Neither place has yet been reclaimed. Farmers usually rebuild small slump scars, even if it takes several years. But even a small slope failure can financially devastate a family if it destroys an entire crop.

Buguias's climate and geology conspire to generate frequent and severe slope failures. Intense and prolonged rainfall periodically saturates a deeply weathered and unstable mantle. Human practices compound the problem. Deforestation and road construction are obvious culprits; many private roads are severely gullied in a single season, while all roadways channel runoff and thus contribute to gullying in nearby fields. Even more destructive is the purposeful diversion of water during floods. When a typhoon strikes, farmers often dig ditches and build embankments to protect their own fields. This funnels the flow into their neighbors' gardens,

who must then redouble their own efforts. A frantic battle ensues, as each grower tries to protect his or her own fields even at the expense of those adjacent.

In the late 1970s the bulldozer appeared as a new agent of erosion. Where agriculture is rapidly expanding, wealthy farmers find it expedient to bulldoze fields of several hectares. Many of the resulting "cut-and-fill terraces" erode severely after a single rainy season. Equipment operators often do not even save the topsoil; instead they merely push it aside to provide a foundation for the terrace fill. This does not usually concern the farmer. Supplied with enough fertilizer, the subsoil yields adequately. And even those agriculturalists who do strive to conserve often find their newly bulldozed fields ravished. One wealthy Buguias couple spent over 30,000 pesos for plastic drain pipes and stone retaining walls for a new field bulldozed near Baguio, but lost virtually the entire investment in a single storm.

With the deforestation of surrounding hillsides, typhoon-induced erosion seems to have become more severe in recent years. The worst disaster to date occurred on July 15 and 16, 1989, when typhoon Goring devastated Buguias, causing fifteen deaths in the municipality. After the storm, the Baguio Midland Courier reported one Buguias elder as saying, "Maybe the gods are angry, there are no more trees on Mount Data."

Many vegetable districts along the Mountain Trail are more susceptible to erosion than is the Agno Valley. Soil loss along the ridge was aggravated, according to most local observers, by careless Chinese farmers who were more concerned with fast profits than with sustainable practices. By the early 1950s, development agents began to focus on erosion control. The state soon insisted that only farmers who had constructed terraces and planted grass or trees on steep slopes could gain land titles. In the 1960s, the Mountain Province Development Authority, with funding from the UN and USAID, initiated a more ambitious bench-terracing project (Baguio Midland Courier July 9, 1967). The irony of teaching some of the world's preeminent terrace engineers how to construct simple earth benches was apparently lost on the sponsors. Moreover, many farmers, particularly sharecroppers, have resisted making the necessary investments for financial reasons, while much land is purposefully kept in slops for wet-season root crops.