SPESIASI DAN BIOAVAILABILITAS Pb DAN Cu DALAM TANAH PERTANIAN ORGANIK SERTA KANDUNGAN LOGAM TOTALNYA DALAM SAYUR PAKCOY (BRASSICA RAPA L.)

Abstract

           Denpasar sebagai salah satu pusat kota penghasil sayur organik di Bali dan juga sebagai daerah destinasi pariwisata, memiliki tingkat pencemaran yang relatif tinggi. Penelitian ini bertujuan untuk mengetahui spesiasi dan bioavailabilitas logam Pb dan Cu pada tanah dan edible part sayur pakcoy yang ditanam di Kota Denpasar. Metode untuk menentukan bioavailabilitasnya menggunakan ekstraksi bertahap dan pengukuran konsentrasi logam Pb dan Cu menggunakan Instrumen AAS (Atomic Absorption Spectrophotometer). Spesiasi logam Pb dominan bersifat berpotensi bioavailable dengan persentase sebelum penanaman dan saat panen sebesar 90,46% dan 79,30%. Sementara itu, spesiasi logam Cu pada tanah dominan bersifat non bioavailable dengan persentase sebelum penanaman dan saat panen sebesar 55,98% dan 48,85%. Kandungan Pb dan Cu total.dalam tanah sebelum penanaman diperoleh sebesar 45,1504 mg/kg dan 84,9271 mg/kg namun, saat panen logam Pb mengalami kenaikan sebesar  99,84% dan logam Cu mengalami penurunan sebesar 12,50% dari kondisi awal. Pada bagian edible part sayur pakcoy kandungan Pb dan Cu sebesar 7,7164 mg/kg dan 20,6295 mg/kg. Berdasarkan Badan Pengawas Obat dan Makanan, sayur pakcoy pada semua lahan dalam penelitian ini tergolong tercemar logam Pb dan Cu karena melebihi ambang batas yang telah ditentukan.

Kata Kunci: bioavailabilitas, logam total, pakcoy, Pb dan Cu, pertanian organik.

ABSTRACT

          Denpasar as one of the city centers in Bali, which produces organic vegetables and is also a tourism destination, has a relatively high level of pollution. The goal of this research was to determine the speciation and bioavailability of Pb and Cu metals in soil and edible parts of Bok choy vegetables grown in Denpasar City. The method used to determine the bioavailability was sequential extraction and the Pb and Cu metal concentrations using the AAS (Atomic Absorption Spectrophotometer) instrument. The speciation of Pb was dominantly potentially bioavailable with the percentage before planting and at harvest of 90.46% and 79.30%, respectively. Meanwhile, the speciation of Cu on the soil was dominantly non-bioavailable with the percentage before planting and at harvest of 55.98% and 48.85%, respectively. The total Pb and Cu contents in the soil before planting were 45,1504 mg/kg and 84.9271 mg/kg, but when harvested, the Pb content increased by 99.84% and the Cu content decreased by 12.50% from the initial conditions. In the edible part of the Bok choy vegetable, the Pb and Cu contents were 7.7164 mg/kg and 20.6295 mg/kg. Based on the Food and Drug Supervisory Agency, Bok choy vegetables in all lands in this study were classified as contaminated with Pb and Cu metals because they exceeded the specified threshold.

Keywords: bioavailability, Bok choy, organic agriculture, total metal, Pb and Cu