Soil and water resources Certified farms are actively involved in long- term conservation of soil and water resources
Dec 26, 2015
Soil and water resources
Certified farms are actively involved in long-term conservation of soil and water resources
Why Consider Long Term Site Why Consider Long Term Site Productivity?Productivity?
It is Basic
Increasing costs from problems with insects and diseases over time.
Need to stay competitive with other CT growing regions.
First rotation field
2003 Productivity Study2003 Productivity Study
First Rotation D. FirFirst Rotation D. Fir Third Rotation D. Fir Third Rotation D. Fir
Types of Analyses Done pHpH NutrientsNutrients Soil carbonSoil carbon Atrazine/Atrazine/
Velpar Velpar residuesresidues
Aggregate Aggregate stabilitystability
Soil densitySoil density
Soil surface lacks good structureSoil surface lacks good structure
Compaction on Christmas Tree Sites
Study Summary for Physical Properties
No widespread decline in physical properties for all sites No widespread decline in physical properties for all sites examined.examined.
Some sites need treatment now.Some sites need treatment now.
Other sites have already been restored by tillage, cover Other sites have already been restored by tillage, cover crops, or other means.crops, or other means.
Physical Properties and Physical Properties and ErosionErosion
Loss in aggregate stability and\or increasing compaction can lead to erosion of surface soil.
Erosion- Poor Drainage or Concentration
Soil Erosion and PNW ClimateSoil Erosion and PNW Climate
Most erosion occurs during rain “events” during the fall and winter.
Overland flow of water is the main culprit.
Loss of surface soil layerLoss of surface soil layer
Soil Erosion Following HarvestSoil Erosion Following Harvest
Rototilled SiteRototilled Site
Erosion After Storm Event
Treatment StrategiesTreatment Strategies
Rest between planting Plant grass cover crop Barriers Incorporate organic material Don’t rip/till when wet
Minimize traffic
Deep ripping/tillage
Why Aggregate Stability Might Why Aggregate Stability Might Drop?Drop?
Excessive tillage/traffic
Erosion
Loss of organic matter
ADVANTAGES OF SOIL TILLAGE
Useful when compaction is unavoidable
Can treat existing compacted area
Can yield other site preparation benefits
Costs may be reasonable & justifiable
Winged SubsoilersWinged Subsoilers
shank & tine mounting & design vary
Add Add wingswings, loosen , loosen moremore soil soil
WingedSubsoiler
DiskHarrow
Soil moisture dry moist to dry
Soil texture all but clayey(large clods)
all textures, including clayey
Rocks & roots up to heavy amounts OK
minimal
Slope limit - downhill
40% 20%
Slope limit - cross slope
15% 10%
Winged Subsoiling vs. Disking:Conditions for Effective Tillage
Andrus & Froehlich 1983
Deep Ripping Between Deep Ripping Between RotationsRotations
MulchesMulches
Straw bales
Cover Crops
Fourth rotation field
There are many options