What is a plow pan?

A plow pan is defined as a hardened layer that forms below the depth of tillage, often as a result of repeated plowing or tilling. When soil is tilled, it can become compacted, particularly at the depth where the plow or tillage implement operates. This compaction creates a barrier that can inhibit root growth, drainage, and the movement of air and water in the soil profile. Consequently, this can lead to potential problems for crops as their root systems struggle to penetrate through the hard layer.

In contrast, the other options do not accurately describe what a plow pan is. A layer of soil from excess organic matter refers to an entirely different concept related to organic content within the soil, while a surface layer of compacted soil speaks to compaction that occurs at the soil surface rather than beneath the tillage depth. The notion of excessive nutrients relates to the chemical aspects of soil fertility and does not pertain to the physical structure or compaction patterns characterized by a plow pan. Thus, understanding the significance of a plow pan is crucial for effective soil management and crop health.