TECHNOLOGY FOCUS - AGRICULTURE - Preferred Process: (B) are of soil origin and inocula are obtained by:(a) applying an aqueous suspension of soil on to a matrix, forming a hydrated zone or biofilm, so that the essentially endogenous bacterial microflora is retained on the surface;(b) allowing the biofilm to mature and establish under oligotrophic conditions so that the most hardy cells migrate to the supernatant phase and progressively dominate it; and(c) recovery and culture of the strains that are most prolific in rich nutrient liquids, i.e. are autochtonous; hardy and persistent in situ; can be grown in liquid media and are suitable for industrial production.The fermentation/formulation step is done in contact with:(i) a carbonaceous support, especially cereal crop residues, and(ii) soil particles, particularly of arable soil.The final powder has moisture content 10-25% and the bacterial titer is over 5plus minus109 per gram. The product is particularly used to coat fertilizers or it is incorporated into fertilizer granules to give a product containing 5plus minus107 cells per gram. The (X) used contains at least 20% carbon, and may comprise biosolids, biomass or other residual materials with fertilizer properties.In the screening method, a bacterial preculture, at ambient temperature and in medium lacking nitrogen and phosphate (other than 'hydroxyapathie') is subjected to an osmotic stress and periodically the optical density (OD) is measured. The difference in OD between consecutive measurements indicates the hardiness of the bacteria. A similar method is used to assess bactericidal activity of a biosolid; a high degree of bactericidal activity being indicated by a low (or negative) change in OD between consecutive measurements.Preferred Bacteria: These are of the families Azobacteracea and Pseudomonacea; especially they are diazotrophic and can dissolve fixed inorganic phosphorus in soil particles. ACTIVITY - Fertilizer.    Maize was grown in a podzol (56% sand; 34% silt; 10% clay) in Quebec. When grown with application of a mixed organic-inorganic fertilizer at 3.8, 14 and 0.3 kg/hectare of nitrogen, phosphorus pentoxide and potassium oxide, respectively, the yield was 103% of that for a sample grown without any fertilizers. The same application of nutrients from a fertilizer inoculated with hardy soil bacteria gave a yield of 109%.    MECHANISM OF ACTION - None given.