What is the ideal angle to evaluate soil in the field?

The ideal angle to evaluate soil in the field is 45 degrees at the toe of the slope because this angle provides a balanced perspective for understanding the soil's properties and behavior. At this point, soil is more likely to exhibit typical drainage patterns and reflect the effects of erosion or deposition processes occurring on the slope above. Evaluating soil at the toe allows for assessing how water movement and sediment accumulation impact soil characteristics, which is crucial for various applications in agriculture, engineering, and environmental management. The 45-degree angle also helps in visualizing the soil profile and identifying any layering or shifts in soil composition that may influence plant growth and stability.

While other angles may give insights into certain aspects of soil, they do not provide the same comprehensive understanding of soil behavior as the evaluation at the toe of the slope does. For instance, evaluating soil at 90 degrees at the top of the slope may overlook critical runoff and drainage issues, whereas evaluating at 30 degrees along the bank may not capture the effects of slope dynamics adequately. The same goes for 60 degrees at the midpoint, which might offer some context but lacks the beneficial features of assessing conditions where soil is most influenced by adjacent slopes and water movement.