Tingkat erosi dan kualitas tanah pada lahan usahatani berbasis kopi di Sumberjaya, Lampung Barat

Abstract

Coffee-based farming has benn perceived by policy makers as causing a high erosion rate and as a source of sedimentation. Past approach to control erosion and restore forest function has been on eviction of the farmers from the forest jurisdiction area and forceful replacement of coffee plants with timber or leguminous tree species such as kaliandra (Calliandra calothirsus).Thih was done because of the myths that forest function restoration can only be done by reforestation by forestry trees. The objectives of this study were to evaluate: (1) The rate of erosion on steep slope coffee-farm with different soil conservation measures, (2) the dominant factors that effect the rate of erosion, (3) impact of forest canversion to coffee farm based on soil quality changes. Three experiments were conducted at Sumberjaya Sub-District, West Lampung District from November 200l -July 2003. Experiment I was aimed at quantifying the level of soil loss on 3 year old coffee farm with slopes ranging from 50 to 60% at Dusun Laksana and Tepus.

Lahan usahatani berbasis tanaman kopi selama ini diyakini para pengambil kebijakan sebagai penyebab laju erosi yang tinggi dan merupakan sumber sedimentasi. Di masa lalu, pendekatan yang dilakukan untuk mengendalikan erosi dan mengembalikan fungsi hutan adalah dengan jalan memindahkan petani yang bermukim dalam kawasan hutan, dan membabat tanaman kopi serta menggantinya dengan tanaman kayu-kayuan atau tanaman dari jenis legum tree seperti kaliandra (Calliandra calothirsus). Hal ini dilakukan berdasarkan suatu keyakinan bahwa perbaikan fungsi hutan hanya dapat dilakukan dengan cara menanam tanaman hutan (menghutankan kembali).