Northeast Region Certified Crop Adviser (NRCCA) Study Resources

In This Section

• PO 27 Health & indicators
• PO 28 Compaction
• PO 29 Compaction in Northeast USA
• PO 30 Long-term intensive crop production
• PO 31 Soil compaction factors
• PO 32 Variable susceptibility
• PO 33 Root/shoot growth, crop yield
• PO 34 Strength & water content
• PO 35 Penetrometer
• PO 36 Degradation from compaction
• PO 37 Soil compaction prevention
• PO 38 Soil compaction remediation
• Summary

Competency Area 4: Soil health and compaction

PO 33. Understand the effect of soil compaction on root and shoot growth, and crop yield.

Root growth is restricted, and shoot growth may be compromised. Seedlings will have difficulty emerging in compacted soils, while shoot growth will be reduced after emergence due to the effects of a reduced root system, nitrogen deficit due to denitrification,  and inhibited root function due to lack of aeration. Crop yields can be reduced 50% in very severely compacted soils, but usually compaction losses will be hard to perceive because they are in the 2-5% range. Effects of surface compaction on crop yields can last for many years, but can usually be remediated in 1 (sandy soils) to 5 years (clay soils). Subsoil compaction, on the other hand, can affect crop yields for more than 10 years.