A collection of nine investigations for students enabling them to follow those transformations occurring in the soil which result in the recycling of nitrogen and the maintenance of fertility.Experiments include:Nitrogen fixation by Azotobacter and RhizobiumHydrolysis of proteins - gelatine - casein - blood proteinDeamination of peptoneOxidation of ammonia and nitriteDenitrification of NitrateThe kit contains:Mannitol Salts MediumNutrient GelatinePeptone WaterAgricultural Dried BloodGlucose Yeast ExtractNutrient Casein AgarCrystal Violet SolutionNitrate Formation MediumNitrate Broth MediumAmmonium Test StripsNitrate Test StripsFull instructionsAdditional materials required (not included):Petri DishesAir dried soilPipettesSterile inoculating loopTest Tubes (sterilised)ParafilmCotton WoolGlass Microscope Slides