For example, plants having absorbed scatols and indols cause increased gas formation during digestion. Cattle only bloat on pastures that have been over spread with mineral fertilizers or fresh manures. D. Plant roots excrete organic acids and enzymes, which in turn favor microorganisms, which in turn release more organic acids and enzymes. In a biologically active soil there is a continuous process of give and take ' release and absorption, availability and taking into storage. E. The plant root rhizosphere is the site of the soil plant interaction.
All biochemical action is dependent on or related to the presence of enzymes.
The variety of living organisms will determine the enzymes' presence and the intensity of biological process. G. Many aerobic microorganisms produce antibiotics that inhibit the spread of pathogens. The availability of phosphate to plant roots in a biologically balanced soil system is entirely different than chemical laboratory availability. Rock phosphates come available slowly, but steadily in an organic system. Most laboratory available phosphate can be fixed as inert iron or aluminum compounds at low pH and as inert calcium compounds at high pH. I. Water soluble potash in a soil goes easily where water moves - upward into the plant or downward away from it.