Soil CompactionBy: Kelly Patches

Soils 401

April 8, 2009

The Problem

3 acre field on my family’s dairy farm has compaction

Compaction forms a “hardpan”

◦ increase bulk density

◦ decrease pore space

◦ ponding/runoff

◦ poor drainage

◦ little to no infiltration of water and nutrients

◦ hard for some roots to penetrate the hardpan

the crops then cannot get the nutrients they need

The Agronomy Facts 63 publication states that “soil

compaction can easily reduce crop yields by 10 percent,

and can lead to water and soil quality degradation due

to increased runoff and soil structure destruction”

(Penn State College of Agricultural Sciences, 2002).

“When pore space shrinks, there is less air and

moisture in the soil, a condition that negatively

influences seed germination, seedling emergence, root

growth, nutrient uptake, and in reality all phases of crop

growth and production” (Penn State College of

Agricultural Sciences, 1996c).

In their study, Egli, et. al. (2007) reported that an

increase of compaction caused less seeds to emergence.

Possible Causes:

◦ spring in corner of field

◦ poorly drained soil

◦ wet spots

◦ right next to a stream

◦ 50 foot buffer

◦ machine traffic

It is my objective to find a solution to

help reduce compaction in this field.

Where is this field?

(Penn State College of Agricultural Sciences, 2009)

Year Crop

2007 Soybeans (no-till)

2008 Corn grain (no-till)

2009 Corn grain (minimum till) (Patches, 2009)

Soil Data

Brinkerton Soil (BrB)

Taxonomic Class

◦ Fine-silty, mixed, superactive, mesic Typic

Fragiaqualf

silt loam

very deep

poorly drained

slow to moderate permeability

slow to rapid surface runoff

slope: 3-8%

formed from acid gray shale and siltstone(Soil Survey Staff, 2009)

Brinkerton Typical PedonHorizon Depth Color Texture Other

Ap 0 to 8 inches Dark grayish brown

(2.5Y 4/2)

Silt loam

Btg1 8 to 14 inches Grayish brown

(2.5Y 5/2)

Silty clay loam Iron accumulation in

matrix; firm

Btg2 14 to 21 inches Grayish brown

(2.5Y 5/2)

Silty clay loam Iron depletions in

matrix; firm

Btxg1 21 to 29 inches Grayish brown

(2.5Y 5/2)

Silt loam Iron accumulation in

matrix; firm, brittle

Btxg2 29 to 34 inches Grayish brown

(2.5Y 5/2)

Silt loam Iron accumulation in

matrix; firm, brittle

Btx 34 to 42 inches Pale brown

(10YR 6/3)

Silt loam Iron depletions in

matrix; firm, brittle

C 42 to 65 inches Brown

(10YR 5/3)

Channery silt loam Iron depletions in the

matrix; firm; 15%

rock fragments

(Soil Survey Staff, 2009)

Solutions

Convert to continuous no-till

Deep-rip the field

Use the lightest equipment and make as

little trips across the field as possible

Plant a cover crop over the winter

Stay off the field when it’s too wet

Haul manure when the soil is frozen

Put alfalfa and soybeans in the crop

rotation

Convert to continuous no-till

Great for conserving soil.

However, high traffic intensity in no-till,

especially since it is a dairy farm.◦ Soil compaction is a concern in no-tillage, especially on dairy and

livestock farms where traffic intensity is high” (Duiker and Sidhu,

2006).

No plowing to break up the compaction.◦ (Penn State College of Agricultural Sciences, 1996b)

Continuous no-till does not improve

compaction.◦ One find was that “[t]he 35-yr NT management compacted soil

more than the 5-yr NT management” (Blanco-Canqui and Lal

2007)

Deep-rip the field

Deep-ripping is a process where a machine,

such as a heavy chisel or a deep-ripper, goes

through the compacted layer, breaking up the

compaction.

Since this field is so wet, deep-ripping will only

cause more compaction.◦ (Patches, 2009)

If equipment is run across the field after deep-

ripping, the compaction can go deeper, because

compaction goes as deep as you rip up the soil.◦ (Patches, 2009)

Use the lightest equipment and as little

trips across the field as possible

A conclusion from the study was that if farmers

can restrict driving on the field to when the soil

is dry and use light equipment, the effects of

compaction will be nominal

◦ (Duiker and Sidhu, 2006)

less equipment = less impact

However, sometimes an unplanned application

of, for example, fertilizer or pesticides, is

needed.

◦ more traffic, more compaction

(Blanco-Canqui and Lal, 2008).

Plant a cover crop over the winter

Cover crops spread weight of the

machines over the root system.◦ (Patches, 2009)

Less impact and compaction per unit of

soil.

Cover crops also help to conserve soil.

Hairy Vetch Rye

WheatAustrian Field Peas

Stay off the field when it’s too wet

When a field is wet, it compacts more easily and

will cause a bigger problem with compaction.◦ (Patches, 2009)

Fields that are poorly drained are more

susceptible to compaction because they are wet

for longer periods of time.◦ (Penn State College of Agricultural Sciences, 1996c)

Staying off the field when wet will reduce the

chances of causing more compaction.

To avoid soil compaction, manure should

not be spread on wet soils.

◦ (Penn State College of Agricultural Sciences,

1996b)

However, if the crop is ready for harvest

but the field is more wet than desired, the

farmer might have to harvest the wet field

anyway to get the much-needed crop in.

Haul manure when the soil is frozen

If the ground is already solid, equipment

will not compact the soil as much as non-

frozen ground.

◦ (Patches, 2009)

Put alfalfa and soybeans in the crop

rotation The roots of alfalfa and soybeans can penetrate the

compaction if it is not too severe.

◦ (Patches, 2009)

Breaking up the compaction with plant roots will help

to lessen the need for another trip across the field to

deep-rip.

A crop rotation system that is well planned can help

avoid soil compaction. Tap roots such as clover can help

to reduce compaction.

◦ (Penn State College of Agricultural Sciences, 1996a)

The Penn State College of Agricultural Sciences (1996c)

suggests that in order to improve drainage, and manage

compaction, farmers should use deep-rooting forage

crops.

My Recommendation

It is my recommendation to implement

the following solutions to reduce

compaction:

◦ use light equipment and try to make as little

trips as possible across the field;

◦ plant cover crops for over the winter;

◦ stay off the field when it is wet;

◦ haul manure when the ground is frozen;

◦ and to put alfalfa and soybeans in the crop

rotation.

References Blanco-Canqui, H., and Lal, R. (2007). Regional Assessment of Soil Compaction and Structural Properties

under No-Till Farming. Soil Science Society of America Journal, 71, 1770-1778.

Blanco-Canqui, H., and Lal, R. (2008). Axle Load Impacts on Hydraulic Properties and Corn Yield in No-

Till Clay and Silt Loam. Agronomy Journal, 100, 1673-1680.

Egli, D.B., Hyatt, J., TeKrony, D.M., and Wendroth, O. (2007). Soil Compaction and Soybean Seedling

Emergence. Crop Science Journal, 47, 2495-2503.

Duiker, S., and Sidhu, D. (2006). Soil Compaction in Conservation Tillage: Crop Impacts. Agronomy Journal,

98, 1257-1264.

Patches, Dean. 2009. Personal Communication.

Penn State College of Agricultural Sciences. (1996a). Conservation Tillage Series, Number One. Crop

Rotations and Conservation Tillage.

Penn State College of Agricultural Sciences. (1996b). Conservation Tillage Series, Number Four. Nutrient

Management in Conservation Tillage Systems.

Penn State College of Agricultural Sciences. (1996c). Conservation Tillage Series, Number Three. Soil

Compaction and Conservation Tillage.

Penn State College of Agricultural Sciences. (2002). Agronomy Facts 63. Diagnosing soil compaction using a

penetrometer (soil compaction tester).

Penn State College of Agricultural Sciences, SoilMap. Retrieved March 2009 from http://soilmap.psu.edu

Soil Survey Staff, Natural Resources Conservation Service, United States Department of Agriculture.

Brinkerton Series. Retrieved February 14, 2009, from Natural Resources Conservation Service Official

Series Description: www2.ftw.nrcs.usda.gov/osd/dat/B/BRINKERTON.html