CSLB C-27 Landscaping ContractorSite Preparation and DrainageHard
A landscape contractor is assessing a site for a new lawn installation. The existing soil exhibits severe compaction due to heavy construction equipment traffic. To effectively remediate this compaction and promote healthy root growth, which mechanical soil preparation technique would be most appropriate?
- ASurface aeration with a core aerator
- BRototilling to a depth of 4 inches
- CDeep ripping or subsoiling to a depth of 12-24 inches
- DApplying a thick layer of sand to the surface
Show answer & explanationAnswer & explanation
Correct answer: C. Deep ripping or subsoiling to a depth of 12-24 inches
Severe compaction from construction equipment often extends deep into the soil profile. Deep ripping or subsoiling, which breaks up compacted layers to depths of 12-24 inches, is the most effective mechanical method to alleviate this type of compaction and allow for proper root penetration and water infiltration.
Why the other options are wrong
- A. Surface aeration with a core aerator is effective for mild, shallow compaction in existing lawns but insufficient for severe, deep compaction from construction.
- B. Rototilling to only 4 inches will not address deep compaction and can create a 'hardpan' just below the tilled layer.
- D. Applying sand to the surface will not alleviate deep compaction and can worsen the situation if not properly incorporated in very high quantities.
Deep Soil Compaction Remediation
Deep ripping or subsoiling is a mechanical technique used to break up severely compacted soil layers (12-24 inches deep) to restore aeration, drainage, and promote root growth.
- Addresses compaction caused by heavy equipment.
- Shatters hardpan layers below the surface.
- Improves water infiltration and gas exchange.
- Essential for establishing healthy plant root systems in disturbed sites.
Memory trick: Deep compaction needs a deep rip to help roots grip.