Which of the following parent materials is most closely associated with the Michigan sod industry?

• A. Organic deposits
• B. Glacial deposits
• C. Lava flows
• D. Alluvial sands

Answer: (A)

The key idea is that soil produced from organic deposits can create the rich, moisture-holding conditions ideal for dense turf production. Organic deposits, such as muck and peat soils, are formed from decomposed plant material in wet environments and accumulate a high level of organic matter. This makes them very fertile and good at retaining nutrients and moisture, which helps turfgrass establish quickly and form a uniform sod when properly drained and managed. In Michigan, large areas have developed muck soils from historic wetlands and lakebed conditions, so the sod industry there is closely tied to these organic-deposit soils.

In contrast, lava flows aren’t present in Michigan, alluvial sands are typically more mineral and well-drained with lower natural fertility, and glacial deposits are widespread but don’t define the specific soil type most associated with Michigan sod production. Therefore, organic deposits are the best fit for the Michigan sod industry.