Transport of microorganisms to groundwater depends mostly on:

• A. Combination of the amount of desiccation (crack and fissures) and rainfall
• B. The amount of microorganisms applied
• C. The size of the microorganisms
• D. The pH of the soil

Answer: (A)

Transport of microorganisms to groundwater is controlled by how water moves through soil. When soils dry, cracks and fissures form, creating preferential pathways that can carry water—and anything dissolved or suspended in it—rapidly downward. Rainfall provides the water that drives this movement. When there is both significant desiccation cracking and substantial rainfall, these pathways become highly connected, allowing microbes to reach groundwater quickly, often bypassing the soil’s usual filtration.

Other factors, like how many microbes are present, the size of the microorganisms, or the soil pH, influence how many microbes are available, how easily they can be transported, or how long they survive, but they don’t govern the actual transport mechanism as strongly as the combination of drying-induced cracks and rain-driven infiltration.