Compaction limits root growth, soil porosity, water movement and water holding capacity, and causes water ponding. And everyone knows that soybeans don’t like wet feet. Growth will stall, and plants are vulnerable to root and stem rots. Unfortunately, compaction can be created quickly but it takes time to fully remediate a breakdown in soil structure so it’s better to prevent it from happening in the first place.
Compaction Avoidance: There are several things we can do to avoid creating unnecessary compaction. They include:
- Avoid working soils when too wet
- Use the smallest equipment vehicle possible for the job
- Reduce axle loads below 10 tons
- Decrease contact pressure by:
- Increasing tire width & height
- Using duals, triples or radials
- Reducing tire pressure
- Using tracks with multiple axles
- Reduce trips across the field
- Utilize controlled traffic lanes
- Utilize auto-steer
- Increase swath width
- Use tillage sparingly
- Minimize depth of tillage
We can also take other proactive steps to increase the resiliency of the soil to resist compaction. They include:
- Adopt conservation systems
- Increase water infiltration
- Decrease evaporation
- Sequester more carbon
- Increase water storage
- Increase soil organic matter
- Increase soil biology
- Manage residue more effectively; recycle nutrients
- Utilize cover crops and crop rotations to improve soil structure
- Consider surface and subsurface drainage improvements
- Add manure and humus compost
- Modify practices that caused compaction (leave three check strips for evaluation purposes)
Adverse Effects of Deep Tillage: Many growers resort to frequent deep tillage or ripping to remediate compaction. There is a time and place for most corrective measures, but one must evaluate the risks and benefits of each. Research shows that deep tillage to eliminate compaction can be beneficial under certain conditions but can also have potential negative effects. These include:
- Reduced soil fertility
- Deterioration of soil structure
- Loss of plant available moisture
- Increase in salt levels
Corrective Actions: We need to employ best agronomic practices both to prevent and correct compaction. Good soil stewardship involves combining wise tillage and managing soil biology to maintain and improve soil health. A biologically active soil will become more resistant to soil compaction. Experience has shown the following to be beneficial:
- Plant diverse crops and cover crops that vary in rooting depth and root types (fibrous vs. taproot).
- Plant crops with roots that break up compacted soils, such as alfalfa or radishes.
- Use “Wise Tillage” as a short-term solution. The soil loosening benefit of tillage can be maintained for longer if roots can be grown to fill the pore spaces soon after tillage.
- Use soluble calcium to increase soil pore space. This can include high calcium lime, gypsum and liquid products such as PractiCal, AgriBoost CA and Caliber.
- Promote soil biology by managing the soil and adding microbial and feedstock soil amendments.