ABSTRAK
Penelitian survey yang mengarakteristikkan tanah gambut dataran tinggi Toba, dilakukan di tiga areal lahan gambut dengan ketinggian berbeda yaitu kecamatan Lintong Nihuta pada areal tertinggi, kecamatan Doloksanggul dan kecamatan Pollung pada ketinggian yang lebih rendah. Analisa tanah di Laboratorium Riset dan Teknologi, Fakultas Pertanian, Universitas Sumatera Utara. Pada masing-masing areal dibuat profil pewakil dan diamati morfologi dan karakteristik serta klasifikasi tanah menurut klasifikasi taksonomi tanah Sampel tanah diambil dari masing-masing lapisan di profil tanah untuk analisis tanah di laboratorium. Analisis tanah meliputi Bulkdensiti, pH H2O, pH CaCl2, KTK, KB, C-organik, N-total, C/N dan DHL. Hasil penelitian menunjukkan bahwa lahan gambut di kecamatan Lintong Nihuta di areal tertinggi memiliki tingkat kematangan fibrik dengan kadar C-organik, nilai KTK dan rasio C/N yang tertinggi tetapi kadar abu terendah, sedangkan areal gambut di kecamatan Doloksanggul di areal yang lebih rendah memiliki tingkat kematangan hemik dengan nilaiC-organik, nilai KTK dan rasio C/N yang lebih rendah tetapi kadar abu lebih tinggi, dan areal gambut di kecamatan Pollung diareal yang terendah dengan tingkat kematangan saprik memiliki nilai C-organik, nilai KTK dan rasio C/N yang terendah tetapi kadar abu tertinggi.Lahan gambut dataran tinggi Toba memiliki perbedaan dengan lahan gambut dataran rendah dalam hal kadar C-organik, KTK, dan proses pembentukannya.
Kata kunci : gambut dataran tinggi, karakteristik tanah, ketinggian tempat
ABSTRACT
Survey research to characterize peat soil of Toba plateau, that conducted in three areas of peat located in three districts with different heights that is district of Lintong Nihuta the highest areal, district of Doloksanggul, and district of Pollung at a lower altitude. Soil analyse properties was held in Riset and Technology Laboratory, Agriculture Faculty of North Sumatera University. Observation in the field of profile on three areas in three locations. Every profiles is observed about morphology and soil characteristic. Soil sample is taken from each layer in soil profile for soil analyse in laboratory. Soil analysis included of bulkdensity, pH H2O, pH CaCl2, Cation Exchange Capacity (CEC), based
saturation, C-Organic content, N-total, C/N ratio and Electrical Conductivity. From research result indicate that peatland in the sub Lintong Nihuta at highest area is peatland with fibrist maturity level, and has the highest C-organic content, CEC, and C/N ratio but lowest Ash content, while peatland in the district of Doloksanggul at lower area is peatland with hemist maturity level, and has the lower C-organic content, CEC, and C/N ratio but higher Ash content, then peatland in the district of Pollung at lowest area is peatland with saprist maturity level, and has the lowest C-organic content, CEC, and C/N ratio but highest Ash content. Peatland plateau have a differences with lowland peat in Organic content, CEC, and formation process.
Keyword : altitude, peat plateau, soil characteristic
