Alih guna lahan hutan menjadi lahan pertanian: ketebalan seresah, populasi cacing tanah dan makroporositas tanah

Abstract

Forest conversion to coffee-based agroforestry initially leads to a decrease in the rate of litterfall and the standing litter layer covering the soil, reducing food for earthworms and replenishment of soil organic matter (SOM) and likely related to a reduction of soil macroporosity. On sloping lands, a reduction of macroporosity and soil cover is likely to increase overland flow and erosion. This research was aimed at quantifying litter thickness, earthworm populations and soil macroporosity in response to land use change, in the Sumberjaya benchmark area (West Lampung), by comparing (a) remnant forest as a control, (b) multistrata shaded coffee with fruit and timber trees as well as the nitrogen-fixing (Erythrina sububrams and/or Gliricidia sepium) as shade trees, (c) shaded coffee with the same nitrogen-fixing Erythrina sububrams and/or Gliricidia sepium as shade trees , (d) monoculture (sun) coffee. Plots were selected with a minimum age of 7 years, in three slope classes: (a) flat (0-10o), (b) medium (10-30o) and (c) steep ( > 30o). The measurements were carried out in November 2001 to Juli 2002