Keanekaragaman Organisme Tanah pada Kelapa Sawit di Daerah Endemik Ganoderma boninense Pat. di Kebun Tanjung Beringin, Langkat

Abstract

Organisme di dalam tanah terdiri atas mikroorganisme dan makroorganisme, organisme tanah memiliki peranan yang sangat penting terhadap kelangsungan kehidupan tumbuhan di atasnya. Penelitian ini bertujuan untuk mengukur keanekaragaman dan mengidentifikasi organisme tanah pada rhizosfer kelapa sawit (tanaman belum melihatkan serangan Ganoderma boninense, tanaman terserang G.boninense, tanaman mendapat perlakuan kitosan Syncephalastrum racemosum) di daerah endemik G. boninense kebun Tanjung Beringin, Langkat. Sampel diambil secara purposive pada 3 rhizosfer kelapa sawit yaitu rhizosfer dengan perlakuan kitosan, rhizosfer sawit terserang Ganoderma dan rhizosfer sawit tanpa gejala Ganoderma. Sampel makrofauna diambil menggunakan 2 metode pitfall trap, kuadrat dan hand sorting. Sampel mesofauna diamati dibawah mikroskop setelah diperangkap menggunakan Barless tullgren funnel. Hasil penelitian menunjukkan pada lokasi rhizosfer kelapa sawit perlakuan kitosan populasi bakteri 41x103 CFU/ml, jumlah isolat bakteri yang didapat 6 isolat, populasi jamur 37,5x102 CFU/ml, jumlah isolat jamur yang didapat 9 isolat, populasi Ganoderma 43,4x101 CFU/ml, derajat infeksi mikoriza 30%, mesofauna ditemukan 4 famili, jumlah makrofauna ditemukan 6 famili. Pada lokasi rhizosfer kelapa sawit terserang Ganoderma populasi bakteri 34x103 CFU/ml, jumlah isolat bakteri yang didapat 5 isolat serta, populasi jamur 39,5x102 CFU/ml, jumlah isolat jamur yang didapat 9 isolat, populasi Ganoderma 67,5x101 CFU/ml, derajat infeksi mikoriza 24,3%, mesofauna ditemukan 10 famili, makrofauna ditemukan 6 famili. Pada lokasi rhizosfer kelapa sawit tanpa gejala serangan Ganoderma populasi bakteri 36 x103 CFU/ml, jumlah isolat bakteri yang didapat 8 isolat, populasi jamur 26 x102 CFU/ml, jumlah isolat jamur yang didapat 16 isolat, populasi Ganoderma 58,3x101 CFU/ml, derajat infeksi mikoriza 11,8%, mesofauna ditemukan 6 famili, makrofauna ditemukan yaitu 4 famili. Dapat disimpulkan pohon yang terkena penyakit busuk pangkal batang mempengaruhi populasi dan keanekaragaman dari mikroorganisme, mesofauna dan makrofauna tanah di daerah rhizosfer kelapa sawit.

Organisms in the soil consist of microorganisms and macroorganisms, soil organisms have a very important role in the survival of plant life on it. This study aims to measure the diversity and identify soil organisms in the rhizosphere of oil palm (plants have not shown Ganoderma boninense attack, plants are attacked by G. boninense, plants are treated with chitosan Syncephalastrum racemosum) in the endemic area of G. boninense in Tanjung Beringin plantation, Langkat. Samples were taken purposively on 3 oil palm rhizosphere, namely rhizosphere treated with chitosan, oil palm rhizosphere attacked by Ganoderma and oil palm rhizosphere without Ganoderma symptoms. Macrofauna samples were taken with 2 pitfall trap methods, squared and hand sorting. Mesofauna samples were observed under a microscope after being trapped with a Barless tullgren funnel. The results showed that at the location of the rhizosphere of oil palm chitosan treatment the bacterial population was 41x103 CFU/ml, the number of bacterial isolates were obtained 6 isolated, the fungal population was 37,5x102 CFU/ml, the number of fungal isolates were obtained 9 isolated, the Ganoderma population was 43,4x101 CFU/ml, the degree of mycorrhizal infection was 30%, mesofauna found 4 families, the number of macrofauna found 6 families. At the location of the oil palm rhizosphere attacked by Ganoderma, the bacterial population was 34x103 CFU/ml, the number of bacterial isolates were obtained 5 isolated and, the fungal population was 39,5x102 CFU/ml, the number of fungal isolates obtained were 9 isolated, the Ganoderma population was 67,5x101 CFU/ml, the degree of mycorrhizal infection was 24,3%, mesofauna found 10 families, macrofauna found 6 families. At the location of the oil palm rhizosphere without symptoms of Ganoderma attack the bacterial population was 36 x103 CFU/ml, the number of bacterial isolates were obtained 8 isolated, the fungal population was 26 x102 CFU/ml, the number of fungal isolates obtained was 16 isolated, the Ganoderma population was 58,3x101 CFU/ml, Mycorrhizal infection degree was 11,8%, mesofauna were found in 6 families, macrofauna were found in 4 families. It can be concluded that trees affected by root rot disease affect the population and diversity of microorganisms, mesofauna and soil macrofauna in the rhizosphere of oil palm.