Abstract: An aqueous extract of legumes is prepared for growing agronomically beneficial microorganisms. The extract is prepared by boiling a legume in water and removing solids. Preferably, 150 to 250 grams of legumes are boiled in about one liter of water for 15 to 30 minutes. The legumes include peas, beans, clover, alfalfa, and mixtures thereof. Also pea seeds can be prepared as a legume aqueous extract. A nitrogen source, a salt of an organic acid, an organic alcohol or mixtures thereof can be added to the extract-containing medium. Furthermore, the extract-containing medium is effective for growing agronomically beneficial microbes to a cell density of 108 cells per milliter.

Abstract: The present invention is directed to a crop inoculant that includes Azospirillum brasilense SAB MKB. The crop inoculant is effective for consistently improving soil quality and increasing plant productivity over a wide range of soil types and climate conditions, and wide range of plant types.