Kuantitas Bakteri Amonifikasi Sebagai Indikator Perbaikan Kualitas Tanah BekasTambang Batubara di Jambi Pasca Revegetasi dengan Tiga Jenis Tumbuhan Pionir: Quantity of Ammonification Bacteria as an Indicator of Soil Quality Improvement at Post Coal Mining Area in Jambi after Revegetation with Three Types of Pioneer Plants

Abstrak

ABSTRACT Open-pit coal mining in Jambi causes massive degradation of physical, chemical, and biological qualities of soil. Revegetation using pioneer plants serves as a primary strategy to restore the ecological functions of the land. This study aims to quantify the population of ammonifying bacteria, analyze soil chemical properties, and examine the causal relationships among these variables in a five-year-old revegetation site. Soil sampling was conducted systematically at depths of 0–5 cm and 5–10 cm beneath three pioneer stands and an unvegetated plot. The Most Probable Number method was employed to enumerate the bacterial population, while chemical analyses included the electrometric method (pH), Furnace method (organic C), and Kjeldahl method (total N). The results indicated that soil depth and plant species had a highly significant effect on the ammonifying bacteria population. The highest population of ammonifying bacteria was found under Jabon at 8.1 Log cells/g of soil, followed by Sengon at 7.8 Log cells/g of soil, and Mahogany at 5.5 Log cells/g of soil, with population sizes decreasing as soil depth increased, while the lowest population was observed in the control site. Soil chemical properties including N-total, C-organic and pH showed strong positive correlations and significantly influenced the increase in ammonifying bacteria quantity, with N-total contributing 51.5%, C-organic 47.4% and pH 42.9% to the effect. The implications of this study prove that revegetation using sengon and jabon is effective in increasing the quantity of ammonifying bacteria, which represents the early improvement of soil quality and fertility in post-mining areas. Keywords: ammonification bacteria, coal mining, pioneer plants, revegetation, soil chemical properties ABSTRAK Penambangan batubara dengan sistem tambang terbuka (open pit mining) di Provinsi Jambi mengakibatkan degradasi kualitas fisik, kimia, dan biologi tanah secara masif. Kegiatan revegetasi menggunakan tanaman pionir merupakan strategi utama untuk memulihkan fungsi ekologis lahan tersebut. Penelitian ini bertujuan untuk menghitung populasi bakteri amonifikasi, menganalisis sifat kimia tanah (pH, C-organik, N-total, rasio C/N), serta menguji hubungan kausalitas antarvariabel tersebut pada lahan revegetasi berumur lima tahun. Pengambilan sampel tanah dilakukan secara sistematik pada kedalaman 0–5 cm dan 5–10 cm di bawah tiga jenis tegakan pionir (Falcataria moluccana, Anthocephalus cadamba, Swietenia macrophylla) dan lahan tanpa vegetasi (kontrol). Metode Most Probable Number (MPN) digunakan untuk menghitung populasi bakteri, sedangkan pengujian kimia meliputi metode electrometric (pH), Furnace (C-organik), dan Kjeldahl (N-total). Hasil penelitian menunjukkan bahwa faktor kedalaman tanah dan jenis tanaman berpengaruh sangat nyata terhadap populasi bakteri amonifikasi. Populasi bakteri amonifikasi tertinggi terdapat pada jenis tanaman jabon (8,1 Log sel/g tanah) diikuti dengan sengon (7,8 Log sel/g tanah) dan mahoni (5,5 Log sel/g tanah), dengan jumlah populasi yang menurun seiring dengan semakin dalamnya lapisan tanah, sedangkan populasi terendah berada pada Lokasi kontrol. Sifat kimia tanah berupa N-total, C-organik, dan pH memiliki korelasi positif yang kuat dan berpengaruh signifikan terhadap peningkatan kuantitas bakteri amonifikasi, dengan kontribusi pengaruh N-total sebesar 51,5%, C-organik 47,4%, dan pH 42,9%. Implikasi dari penelitian ini membuktikan bahwa revegetasi menggunakan jenis Falcataria moluccana dan Anthocephalus cadamba efektif meningkatkan kuantitas bakteri amonifikasi yang merepresentasikan awal perbaikan kualitas dan kesuburan tanah bekas tambang batubara. Kata kunci: bakteri amonifikasi, revegetasi, sifat kimia tanah, tambang batubara, tanaman pionir

Kata kunci

• ammonification bacteria
• coal mining
• pioneer vegetation
• revegetation
• soil cemical properties