Below the dark, crumbly topsoil lies a harder, paler layer. Subsoil holds fewer nutrients and less organic matter, but it still matters. Roots penetrate it for water and anchorage, and its structure affects drainage across the whole profile.

Subsoil forms as water carries clay and minerals down from above. Over time it accumulates materials that leach out of topsoil, which is why it often has higher clay content. Compacted subsoil restricts roots and traps water, creating problems that show up in the crop above.

Common subsoil issues

• Hardpan layers blocking roots
• Poor drainage causing waterlogging
• Low organic matter limiting biological activity
• Acidity that restricts root growth

Deep ripping or subsoiling breaks compaction without turning the soil over. The practice is expensive and not always effective, but it can restore rooting depth in fields where traffic has caused damage.