Efektivitas sterilisasi iradiasi sinar gamma CO-60 dan mesin berkas elektron terhadap berbagai bahan pembawa serta viabilitas inokulan dalam bahan pembawa arang batok dan zeolit

Abstract

Biofertilizer is a substance containing living microorganism such as nitrogen fixing bacteria, phosphate solubilizing microorganism and organic matter decomposing microorganism which applied to seed, plant surface or soil to improve growth and increasing supply of availability of primary nutrients to the plant. Application of biofertilizer becomes alternative fertilizer to support application of chemical fertilizer to preserve the environment. Biofertilizers are packaged on carrier material such as peat, charcoal, compost, zeolite and others which can provide ideal home and keep the effectiveness of microorganism during storage period. Carrier is important thing to determine the quality of biofertilizer. The property of good carrier is free for unwanted indigenous microorganism to keep high number of inoculants microorganism, so that must be carrier sterilization. The purpose of this research was to investigate the effectiveness of Gamma Irradiation Co-60, Electron Beam Machine (EBM) and autoclave toward decreasing the number of indigenous microorganism on carrier material coconut shell charcoal, zeolite, wood charcoal and peat from Rawa Pening. Beside that to investigate viability of Azospirillum, Azotobacter and Phosphate Solubilizing Fungi inoculants on carrier material coconut shell charcoal and zeolite. Sterilization of Gamma Irradiation Co-60 and EBM conducted in PATIR – BATAN, while sterilization of autoclave, sterility tests and viability tests conducted in Laboratory of Soil Biotechnology, Agricultural Faculty, IPB. The result shows using Gamma Irradiation Co-60 at 50 kGy, Electron Beam Machine (EBM) and autoclave are effective to sterilize indigenous microorganism on carrier materials with minimum detection limit was 102 cfu/g. The result of viability of Azospirillum, Azotobacter dan Phosphate Solubilizing Fungi inoculants on sterilized carrier material by Gamma Irradiation Co-60, EBM and autoclave tended to decline during storage 70 days at room temperature (250C). Viable cell Azospirillum inoculants on zeolite sterilized by Gamma Irradiation Co-60 and autoclave give best performance of viability test with decreased number of cell were 11.11 %. While using autoclave toward coconut shell charcoal leads to decrease viable cell of Phosphate Solubilizing Fungi inoculants to 99.75 % aimed that autoclave was not best method of sterilization.