Penentuan Karakteristik Tanah Secara Kualitatif di Lapangan Kampus Sekolah Vokasi IPB

Abstract

Karakterisasi tanah merupakan langkah awal yang penting dalam evaluasi sumber daya lahan, baik untuk keperluan budi daya pertanian maupun pengelolaan lingkungan. Mini project ini bertujuan mengenali karakteristik tanah secara cepat dan kualitatif di Lapangan Kampus Sekolah Vokasi IPB, Desa Babakan, Kecamatan Bogor Tengah, Kota Bogor, berdasarkan sifat fisika, kimia, dan biologi. Pengamatan dilakukan secara langsung di lapangan pada 13 Januari 2022 melalui pembuatan profil mini sedalam 50 cm. Parameter yang diamati meliputi bentuk lahan, bahan induk, ketebalan lapisan atas, struktur, tekstur, warna (sistem Munsell), konsistensi, reaksi tanah (pH), kandungan kapur (uji HCl), kandungan bahan organik (uji H₂O₂), serta keberadaan makroorganisme tanah. Hasil pengamatan menunjukkan lokasi berupa dataran rata (kemiringan 0–8%) dengan bahan induk aluvium bercampur abu vulkanik. Lapisan atas (top soil) setebal 0–24 cm berstruktur gumpal membulat (subangular blocky), bertekstur silty clay loam pada lapisan atas dan clay loam pada lapisan bawah, serta berwarna 5YR 3/3 (dark reddish brown) di lapisan atas dan 5YR 4/4 (reddish brown) di lapisan bawah. Konsistensi lembab tergolong teguh, dengan kelekatan yang meningkat ke arah lapisan bawah. Reaksi tanah berkisar agak masam hingga netral (pH 5–7), tidak mengandung kapur bebas (negatif terhadap HCl), serta menunjukkan kandungan bahan organik tinggi pada lapisan atas dan sedang pada lapisan bawah berdasarkan intensitas reaksi terhadap H₂O₂. Ditemukan cacing tanah sebagai indikator aktivitas biologi yang baik. Berdasarkan keseluruhan ciri morfologi tersebut, tanah secara tentatif diduga termasuk ordo Inceptisol yang berkembang dari bahan aluvium-volkanik, dengan tingkat kesuburan sedang serta drainase dan aerasi yang baik.

Kata kunci: aluvium, bahan organik tanah, Inceptisol, karakteristik tanah, sifat fisika tanah.

Abstract

Soil characterization is an essential first step in land resource evaluation for both agricultural production and environmental management. This study aims to rapidly and qualitatively characterize the soil at the campus field of the Vocational School of IPB University, Babakan Village, Bogor Tengah Sub-district, Bogor City, West Java Province, based on its physical, chemical, and biological properties. Direct field observation was carried out on 13 January 2022 by excavating a 50 cm mini soil profile. The observed parameters included landform, parent material, topsoil thickness, structure, texture, colour (Munsell system), consistence, soil reaction (pH), carbonate content (HCl test), organic matter content (H₂O₂ test), and the presence of soil macro-organisms. The site is a flat plain (0–8% slope) with alluvial parent material mixed with volcanic ash. The topsoil (0–24 cm) had a subangular blocky structure, a silty clay loam texture in the upper layer and clay loam in the lower layer, with colours of 5YR 3/3 (dark reddish brown) and 5YR 4/4 (reddish brown), respectively. The moist consistence was firm, with stickiness increasing with depth. Soil reaction ranged from slightly acidic to neutral (pH 5–7), the soil was free of carbonate (negative to HCl), and organic matter content was high in the topsoil and moderate in the subsoil based on the intensity of the H₂O₂ reaction. Earthworms were found as an indicator of good biological activity. Based on these morphological features, the soil is tentatively classified as an Inceptisol developed from alluvial-volcanic material, with moderate fertility and good drainage and aeration.

Keywords: alluvium, Inceptisol, soil characteristics, soil organic matter, soil physical properties.