Soil Tech Note 9A- Large Microbes

Large Microbes

PROBLEM:   “I guess I see why I need some of those little critters in the soil but are there any large ones I need too?”

LOW LARGE-MICROBE POPULATION PROBLEM CAUSED BY: 

• Excessive tillage.
• Drainage issues, too wet or too dry.
• No residue cover to control surface temperature.
• Absence of smaller microbes that larger ones feed on.

WHAT DAMAGE IS CAUSED IF NOT PRESENT: 

• If no large microbes (nematodes, arthropods, protozoa) are in the soil the bacteria and others can overpopulate the soil environment. 
• Large microbes can create larger openings in the soil that will increase porosity of the soil for both air and water.
• Some of the smaller microbes in the soil can have very rapid changes in numbers due to temperature, moisture or disturbance factors.  Larger microbes tend to be a more stable population although in much smaller numbers.

POSSIBLE SOLUTIONS: 

• Reduce tillage disturbance.
• Cover crops provide food source for smaller microbes which many of the larger ones prey on.
• Sufficient variety of residue will allow larger microbes food for shredding purposes.
• Adequate drainage and aeration of the surface layer is necessary.

Avoid bare soil surfaces that will heat up dramatically and can reduce population.