609 - 1

NATURAL RESOURCES CONSERVATION SERVICE

CONSERVATION PRACTICE STANDARD

SURFACE ROUGHENING

(Ac.)

CODE 609

DEFINITION

Performing tillage operations that create 

random roughness of the soil surface

PURPOSE

This practice is applied to support one or 

more of the following:

• Reduce soil erosion from wind and windborne sediment deposition.

• Improve plant health by protecting the

growing crops from damage by wind-borne 

soil particles.

• Improve air quality by reducing the 

generation of airborne particulate matter. 

CONDITIONS WHERE PRACTICE APPLIES

This is for emergency tillage on soils that have 

a surface layer suitable for clod formation and 

have a high potential for wind erosion due to 

lack of surface cover. This practice should not 

be used as a primary erosion control practice.

GENERAL CRITERIA APPLICABLE TO ALL 

PURPOSES

Tillage operations will produce random 

roughness (RR) values (inches) large enough 

to achieve a 25% reduction in the potential 

erosion rate, OR reduce wind erosion during 

the management period by 25% as determined 

by the most current wind erosion technology.

Additional Criteria to Protect Plants from 

Abrasion by Wind Blown Soil Particles

Tillage operations for this purpose will produce 

random roughness sufficient to reduce erosion 

to the planned soil loss objective to protect the 

growing crop. See National Agronomy Manual 

Table 502-1 for crop tolerances for wind 

erosion.

CONSIDERATIONS

This practice should be used when a wellplanned and properly applied wind erosion 

control system fails for reasons beyond the 

control of the producer. These situations may 

exist when a low residue-producing crop is 

planted too late in a growing season to produce 

sufficient residue cover, or when the planned 

erosion control system fails to control erosion 

during a high wind event.

Wide spacing of chisel points or skip chiseling 

(alternate chiseled/non-chiseled strips) for the 

first operation may permit salvaging part of a 

growing crop of small grain and leave 

undisturbed soil for later operations, if needed. 

Spacing and depth of chisel operation are 

important to obtain uniform distribution of clods 

on the surface. Close spacing at shallow 

depths generally pulverizes the soil, and does

not produce enough random roughness to 

decrease the soil-blowing potential.

Proper tillage equipment matched to the crop 

being grown and soil is important. In general, 

chisels or narrow sweeps may reduce potential 

NRCS, NHCP

September 2014

Conservation practice standards are reviewed periodically and updated if needed. To obtain 

the current version of this standard, contact your Natural Resources Conservation Service 

State Office or visit the Field Office Technical Guide.
609 - 2

soil blowing on loamy or fine textured soils. 

Roughening the soil surface with a 

lister/bedder or wide shovels on chisel shanks 

is more effective on soils whose surface layer 

has a wind erodibility factor (I) value of 104 and 

86.

Emergency tillage (surface roughening) can be 

done on soil that has an “I” factor greater than 

104 using deep tillage, when soil moisture is 

adequate to create a stable aggregate (clod) 

and when finer soil material can be brought to 

the surface.

Perform the initial tillage operation as soon as 

erosion starts, or as soon as it is evident that 

the existing cover or surface roughness is 

inadequate to control erosion below an 

acceptable level.

Begin surface roughening operations on the 

windward (up wind) edge of the field.

Ridging associated with the tillage is very 

important to controlling wind erosion. Tillage 

that creates ridging is done perpendicular to 

the direction of damaging wind. See 

conservation practice standard Cross Wind 

Ridges (588) for criteria to use ridging.

Surface crusts generally reduce soil erodibility. 

However, certain smooth, crusted soils with 

loose grains (sand size particles) on the soil 

surface may cause crusts to abrade rapidly. 

These soils include loamy fine sands and 

sandy loams that have significant portions of 

sand on the surface when crusted. They also 

include certain calcareous loams, silt loams, 

and silty clay loams that tend to form sand 

sized aggregates in the surface when crusted.

PLANS AND SPECIFICATIONS

Prepare plans and specifications for each field 

or treatment unit according to the Criteria and 

Operation and Maintenance requirements of 

this standard.

Specifications shall describe the application 

requirements to achieve the intended purpose.

Record practice specifications in an approved 

Surface Roughening, 609, Implementation 

Requirements document.

OPERATION AND MAINTENANCE

This practice will be performed as soon as 

possible when there is inadequate cover to 

protect the soil from potential wind erosion 

events or when a crusted soil condition occurs 

as sensitive crop is emerging and inadequate 

crop residues are present.

REFERENCES

USDA, Natural Resources Conservation 

Service, National Agronomy Manual, 4P

thP

Edition, Feb. 2011. Website: 

31TUhttp://directives.sc.egov.usda.gov/U31T Under 

Manuals and Title 190.

Wind Erosion Prediction System (WEPS) 

website: 

http://www.nrcs.usda.gov/wps/portal/nrcs/main/

national/technical/tools/weps/

NRCS, NHCP

September 2014