Define "compaction" in soil management.

Compaction in soil management refers to the process that increases soil density, decreases pore spaces, and limits root growth. This occurs when soil particles are pressed together, often due to heavy equipment or excessive foot traffic. As the density of the soil rises, the spaces between the particles (pore spaces) become reduced. This reduction in pore space can lead to a variety of negative effects on plant health, including limited water infiltration, reduced aeration, and restricted root expansion. In compacted soil, roots may struggle to grow and uptake essential nutrients due to the tightly packed nature of the soil. Understanding compaction is crucial for effective soil management, particularly in landscaping and agricultural practices, as it impacts plant health and soil function.

In contrast, the other options describe processes or characteristics that do not align with the definition of compaction. For instance, the increase of organic matter pertains to improving soil quality rather than the physical density of the soil itself. Similarly, decreasing soil density and increasing pore spaces signifies the opposite of compaction, while the arrangement of soil particles in layers reflects soil structure rather than density-related issues. Therefore, recognizing the implications of compaction is essential for any landscaping professional aiming to maintain healthy soil conditions.