B4 is a blend of 4 highly beneficial bacillus microorganisms: Bacillus licheniformis, Bacillus amyloliquefaciens, Bacillus pumilus and Brevibacillus laterosporous. B4 solubilizes phosphorous(P), zinc (Zn) and iron (Fe) that are in the soil and unavailable to your crop. These elements are made unavailable in the soil by other elements, iron, aluminum, calcium. It takes many years for P, Zn, Fe to naturally break down and become available to feed your crop.