Restoring the productivity potential of Mt. Pinatubo-affected soils

Abstract

After the Mt. Pinatubo eruption, researches had to be directed towards the rehabilitation of the volcanic ash deposits (lahar)-affected areas. Land-use and management technologies were tested in a 1 m × 1 m × 0.5 m microplot. Analysis of the lahar used in the experiment showed significantly low organic matter, cation exchange capacity, exchangeable K and reduced levels of silt and clay. The yield of rice was very poor on the pure lahar, but it was improved by mixing with clay loam soil at the ratios of 1:3 to 3:1 and fertilizer application. The yield of corn was not affected much by the different thickness of lahar-cover on the soil, but considerably increased by inorganic fertilizer application. Results of the different trials revealed that the decreased productivity of the soils covered by lahar could be restored by mixing with soil and proper fertilization.