The Understanding around Soil Compaction in Crop Production

John Fulton

CompactionSmart, Waterloo, ON

Your decision on field operations / practices:

• Right decision… • Wrong decision…

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Identifying Man- / Machine-made Vs. Natural variability

NDVI Image Early July Corn

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Soil

Organic Matter (OM) 5%

Water 25%

Air 25%

Mineral Matter 45% Preferred Composition

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Soil is Alive – bacteria and other organisms

Soil is Porous – pore spaces absorb air and water plus deliver nutrients

Soil is Nutrient-Rich – N, P, K and other micros vital to plant nutrition

Image Source: www.extension.umn.edu/agriculture/tillage/soil-compaction

Physical

Chemical

Biological

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Soil Compaction│soil particles compressed together, reducing pore space.

Soil Compaction – decrease in soil volume and porosity, or increase in soil bulk density due to mechanical stress. Compaction could also be cause naturally.

• Surface Compaction – compaction that occurs at

the upper soil layer; considered within the tilled layer of soil.

• Subsoil or Deep compaction – compaction that occurs below the tilled layer as a result of surface loading.

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• Decreased infiltration • Reduced nutrient uptake • Reduced root developed

and rooting depth • Reduced water holding

capacity • Increased soil erosion • Crop YIELD!

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Soil Compaction in Crop Production

• Mass is mass for machinery and implements (e.g. axle loads) • 70% of a field can be trafficked annually • Improving soil health reduces influence of machinery loadings

• Enables soil to recover quicker.

• 75% to 80% of soil compaction occurs on 1st pass • Repeated loadings increase soil compaction

• Heavy traffic soils retain moisture longer, recharge slowly and warm up slower. • Delays in emergence

• Can reduce corn yield between 10-35 bu/ac and up to 60% in poor conditions. • 10-ton axle loads or greater significantly increase the potential. Requiring

improved farm management to deal with compaction.

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Machinery Compaction • Soil conditions (wet vs. dry) • Excessive machine/implement loading

• Axle load • Wheel configuration / Tracks • Frequency of loading (75% to 80% of

compaction occurs on 1st pass)

• Soil structure

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Soil Moisture│moisture at the time of field operations impacts level of soil compaction.

Image Source: Wolkowski and Lowry, 2008

Dry – compaction can promote good seed-soil contact at planting. Wet – increased potential of compaction; decreasing aeration and nutrient uptake while increasing denitrification and root disease.

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Soil Moisture│increase in moisture increases depth of influence.

Image Source: Sohne, Agricultural Engineering

Soil Texture: Bulk Density vs. Soil Resistance

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Hand Penetrometer (2 Mpa) Bulk Densities that limit root and crop growth

Constant insertion velocity = 1.2 in/sec (28 mm/sec)

Augment or Mitigate Soil Compaction

• Avoidance • Machinery and implement decisions

• Axle loads • Right tool for the right job

• Timing of field operations • Tillage • Build Soil Health

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Soil Resistance

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Loading Interaction with Soil

• Point loading • Area loading

o Implement type and configuration o Tire configuration o Tire pressure o Tracks

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Vertical Tillage (VT)

• Residue fractionation - break down tough corn residue more quickly for improved seedbed next spring.

• Sold as a low impact form of tillage • Not a form of input incorporation

• Point loading • Consider soil conditions when

operating!

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Tandem Disk Harrow

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Soil Resistance by Implement

Source: www.extension.umn.edu/agriculture/tillage/soil-compaction

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Biology of Soil Compaction

Source: Hoorman et al., 2009. Ohio State University

5 ways Soil Organic Matter Resists Soil Compaction • Surface residue resists compaction; sponge to

absorb weight and water.

• Organic residues are less dense than soil particles. • Roots create voids and spaces for air and water. • Roots act like a biological valve to control oxygen

in the soil.

• Roots supply exudates to glue soil particles together to form macroaggregates and supply food for microbes.

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Diverse Cover Crops: Winter pea and radish

Nodules

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Soil Health/Healthy Soil - What is It?

The continued capacity of the soil to function as a vital living ecosystem that sustains plants, animals, and humans

• Nutrient cycling • Water (infiltration & availability) • Filtering and Buffering • Physical Stability and Support • Habitat for Biodiversity

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Grower Value: Improving soil health reduces the risk of soil compaction plus increases the recovery of the soil to compaction.

New Tools for Identification As-planted data Imagery Machine data

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Hidden variables impacting crop development and yield… COMPACTION (soil health component) Question: How do we identify and quantify?

Tractor tire paths visible after field cultivator

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As-Planted Data: Row-Unit Ride Quality Map

In-Cab Display Feedback

Producer Value 1) Identify and correct equipment issues immediately.; 2) Execute

prescriptions; 3) Identify soil characteristics (e.g. clods, trafficked areas)

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1.5 months after planting

Decision --- ½ day too early on field cultivator!

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Question: How do we identify and quantify? Answer: Using Imagery & machine data.

Machine Data CAN messages, Health, etc. Effective tool to evaluate operating costs and

capacity --- FUEL USAGE, UPTIME vs. DOWNTIME, ENGINE LOAD.

“You can't manage what you don't measure!“ (W. Edwards Deming)

Managing to Avoid Compaction Problems

• Controlled Traffic (GPS guidance) • Bigger tires, lower inflation pressure • Variable inflation pressure

(correct psi for in-field and on road) • More axles, less weight/axle • Rubber tracks • Continuous No-Till • Cover Crops

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Digital Agriculture Providing solutions to meet world demand John Fulton Fulton.20@osu.edu 334-740-1329 @fultojp

Ohio State Precision Ag Program www.OhioStatePrecisionAg.com Twitter: @OhioStatePA Facebook: Ohio State Precision Ag

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