What type of soil has high organic content, leading to higher water retention?

The type of soil that has high organic content and leads to higher water retention is smooth, clay silt. This soil composition typically contains a significant amount of organic matter, which enhances its ability to hold water. Clay particles are very small and packed closely together, creating a fine texture that increases the surface area for water storage. Additionally, organic matter acts like a sponge, absorbing moisture and improving the soil's overall structure and fertility.

In contrast, coarse sand and gravel consist of larger particles with considerable space between them, which allows water to drain quickly rather than being retained. Sandy loam, while having a mix of sand and silt, generally has lower organic content compared to smooth, clay silt and doesn't retain water as effectively. The combination of small clay particles and organic material in smooth, clay silt makes it the ideal choice for high water retention.