Abstract: Bacterial preparation which comprises material belonging to genus Bacillus, producing lipopeptides which decrease surface tension of water, and possessing an ability to propagate in soil in the presence of vegetable cellulosic materials under anaerobic condition, and of bacteria belonging to genus Bacillus or genus Clostridium, producing cellulases and possessing an ability to propagate in soil in the presence of vegetable cellulosic materials, and preferably of bacteria belonging to genus Bacillus or genus Clostridium, fixing nitrogen and possessing an ability to propagate in soil in the presence of vegetable cellulosic materials under anaerobic conditions. Examples of lipopeptide-producing bacteria are: B. subtilis, B. licheniformis, B. circulans; examples of cellulases-producing bacteria are: B. subtilis, B. licheniformis, B. circulans, B. polymyxa, B. coagulans, B. macetans, Cl. cellulolyticum, Cl. aerotolerans, Cl. acetobutylicum, examples of nitrogen-fixing bacteria are: B. azotofixans, B. macerans, B.