United States Department of Agriculture 601-CPS-1

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July 2021

NRCS reviews and periodically updates conservation practice standards. To obtain the current 

version of this standard, contact your Natural Resources Conservation Service State office or 

visit the Field Office Technical Guide online by going to the NRCS website at 

https://www.nrcs.usda.gov/ and type FOTG in the search field. 

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Natural Resources Conservation Service 

CONSERVATION PRACTICE STANDARD 

VEGETATIVE BARRIER 

CODE 601 

(ft)

DEFINITION 

Permanent strips of stiff, dense vegetation established along the general contour of slopes or across

concentrated flow areas. 

PURPOSE 

This practice is used to accomplish one or more of the following purposes: 

• Reduce sheet and rill erosion 

• Reduce ephemeral gully erosion 

• Reduce sediment transport to surface waters 

CONDITIONS WHERE PRACTICE APPLIES 

This practice applies to all land uses where sheet and rill erosion or ephemeral gully erosion are resource

concerns. 

CRITERIA 

General Criteria Applicable to All Purposes 

Physical characteristics of plants 

Stiffness index 

Establish vegetative barriers with vegetation having the minimum Vegetation Stiffness Index (VSI)

designated in table 1, measured at a point 6 inches above the ground. 

Table 1. Stem Diameter and Minimum Stem Density Values for Vegetation Stiffness Index (VSI)

Values of 0.05 and 0.10. 

Stem Diameter (Inch)

Concentrated Flow Areas 

Stem Density Per Square Foot

@VSI=0.10

Other Purposes 

Stem Density Per

Square Foot

@VSI=0.05

0.10 1000 500

0.15 200 100

0.20 60 30

0.25 30 15

0.35 7 4

0.50 2 1

=/>1.00 1 1.0
Density 

Establish plants so that gaps between plants are no greater than 3 inches at the end of the first growing

season. 

Species selection 

Select species adapted to local soil and climate conditions, easily established, long-lived, and

manageable. Use species that exhibit characteristics required for adequate functions, such as emergence

through several inches of sediment or resuming growth from buried stem nodes, rhizomatous or

stoloniferous growth habit, and stems that remain intact and erect year-round. 

Establishment 

Establish barriers vegetatively or from seed. 

Seeding dates, depths, and rates must be appropriate for the species selected and the conditions of the

site. Ensure good seed-to-soil contact when planting seeds by rolling or packing the soil after seeding. 

Plant barriers established vegetatively at a density to ensure a functional barrier as quickly as possible

(usually two growing seasons). For most herbaceous species, this will require a spacing in the row of no

more than 6 inches for bare-root seedlings, cuttings, sod chunks, plugs, rhizomes, or divisions consisting

of no less than 5 viable stems. For suckering shrubs or herbaceous species established from 6-inch

(gallon) potted material use a spacing in the row of no more than 12 inches. 

Prepare the site sufficiently to ensure seed germination or proper rooting conditions for vegetative

material establishment. Ensure good root-to-soil contactby packing the soil after planting. 

If necessary use appropriate site stabilization measures , during the barrier establishment period. 

The mature barrier widths must be the larger of 3-feet wide or 0.75 times the design vertical interval. Sow

broadcast or drilled seed in a strip at least 3-feet wide. When using a row planter, plant a minimum of 2

rows. 

Do not use plant materials considered invasive or noxious for the vegetative barrier 

Additional Criteria for Reducing Sheet and Rill Erosion 

Gradient 

Layout vegetative barriers so the gradient along the barrier is at least 0.2 percent and no greater than 1.0

percent, except where the vegetative barrier crosses concentrated flow areas. For barriers entering a

concentrated flow area, gradients may be up to 1.5 percent for 100 feet for better row alignment. 

Conduct all tillage and equipment operations in the interval between barriers parallel to the vegetative

barrier. 

Construct and maintain a berm or channel immediately upslope from the barrier to divert water along the

vegetative barrier. Use a minimum berm height/channel depth of 3 inches. Water flowing along a

vegetative barrier berm/channel must flow into a stable outlet. 

Spacing 

Determine the horizontal spacing between the vegetative barriers using the lesser of— 

• The horizontal distance between barriers when the vertical interval is 6 feet, or 

• The water erosion planning length of slope “L” that achieves the allowable soil loss for the field,

considering the planned practices in the conservation management system. 

Plan crop strip widths in multiples of the widths of planting, tillage, spraying, and harvest equipment. This

spacing may be adjusted up to 10 percent between the barriers. 

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Vegetation 

The species composition will provide the designated minimum stem density with the designated stem

diameter and have a minimum VSI of 0.05. See Table 1 for guidance. 

Additional Criteria to Reduce Ephemeral Gully Erosion 

Alignment 

Install vegetative barriers across concentrated flow areas perpendicular to the direction of water flow. 

Width and length 

Vegetative barriers will consist of a minimum of two rows. Length of the vegetative barrier will vary

depending on the topography. Each strip must be long enough to ensure that the ends of the strip are at

least 1.5 feet higher than the center of the concentrated flow area (see table 1). When the concentrated

flow area has a preexisting headcut, place one barrier at the bottom of the headcut and the other at the

top. 

Spacing 

Base spacing between the vegetative barriers on the vertical interval of 1.5 feet for conditions where no

tillage is performed between the barriers and 3 feet for all other conditions where sediment deposition and

bench development is anticipated. 

Minimum level bottom section length 

Design the minimum level bottom section length (in feet) numerically equal to the peak discharge [in cubic

feet per second (cfs) for a 2-year 24-hour design storm from the total watershed upslope of the lowest

barrier. This equates to a specific discharge of 1 cfs/ft of vegetative barrier. Level bottom section is

defined as the bottom width of a trapezoidal waterway. This will be shaped during construction or formed

by sediment deposition. (See table 1) Use methods in chapter 2 of the NRCS National Engineering

Handbook (NEH) (Title 210), Part 650, “Engineering Field Handbook” to estimate peak discharge for local

soil, climate, and management conditions. 

If the channel does not have a level bottom section, design the barriers so that the peak discharge

through the barrier for a 2-year, 24-hour storm does not exceed allowable velocities for the soil,

vegetation, and slope conditions as determined using chapter 7 of 210-NEH-650. 

Vegetation 

Establish species that will provide the designated minimum stem density with the designated stem

diameter and have a VSI of 0.10. See table 1 for guidance. 

CONSIDERATIONS 

The “benching” process that occurs on slopes where barriers are installed (tillage erosion moves soil from

the upper part of the cropped strip, which then accumulates in the lower part of the cropped strip) can

expose soil material that is unfavorable for crop growth. 

Using management practices such as NRCS Conservation Practice Standards (CPSs) Conservation Crop

Rotation (Code 328) and the Residue and Tillage Management (Codes 329 and 345), with Vegetative

Barrier (Code 601) increases the effectiveness of the barrier. 

This practice may improve the efficiency of other practices such as stripcropping, filter strips, riparian

forest buffers, grassed waterways, diversions, and terraces. 

Practices such as water and sediment control basins, subsurface drainage, and underground outlets may

be needed to adequately handle surface and subsurface water. 

Established vegetative barriers systems can pond water above the barriers. Subsurface drains may need

to be installed across the slope parallel to the barrier, or through the ponded areas above barriers that are

installed across concentrated flow areas. 

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When compatible with the purposes and criteria for this practice, use plant materials that attract

undesirable insects away from crops or desirable insects that are beneficial to the adjacent crops. 

When compatible with the purposes and criteria for application of this practice, select plant materials that

enhance food and cover for targeted wildlife. 

When compatible with the purpose and the barrier vegetation, avoid conducting activities within the barrier

during the nesting season to minimize impacts to birds. 

Stagger rows of planted vegetation to increase resistance to overland flow through the vegetated barrier 

Mowing in concentrated flow areas is discouraged because it will lower the vegetation stiffness index by

reducing average stem diameter. 

PLANS AND SPECIFICATIONS 

Develop plans and specifications for each field or treatment unit according to the Criteria section

requirements above, and Operation and Maintenance section requirements below. Specifications must

describe the requirements to apply this practice to achieve the intended purpose. Record the following

specification components in an approved NRCS CPS Vegetative Barrier (Code 601) implementation

requirements document. 

• Field map with location of vegetative barriers 

• Purpose of the barrier 

• Width of crop strip (when appropriate) 

• Vegetative barrier and crop strip orientation (when appropriate) 

• Width of each barrier 

• Linear feet of barrier 

• Vegetative species 

• Establishment date, establishment method, seeding rate (when seeded), or spacing of vegetative

planting stock 

• Site stabilization and/or preparation 

OPERATION AND MAINTENANCE 

Prepare an operation and maintenance plan for this practice. As a minimum include — 

• Replant or reseed establishment failures immediately; gaps in seeded barriers may be

reestablished more effectively and immediately with transplanted plant material. 

• Mowing of vegetative barriers may be used as a management practice to encourage the

development of a dense stand and prevent shading of crops in adjacent fields. Mow at a 15-inch

stem height, or the recommended height for the species, whichever is taller. 

• Barriers may be periodically burned (where permitted), if the species used will tolerate fire. Carry

out burns just prior to the spring regrowth period, while the vegetation is dormant. All burns will be

conducted in accordance with a smoke/burn management plan. 

• Control weeds as necessary to ensure a dense stand within the barrier by mowing, spraying, or

wick application of labeled herbicides. 

• Do not use vegetative barriers as a field road or turn row. Vegetative barriers in concentrated flow

areas will not be crossed with machinery. 

• Do not cut vegetative barriers with water furrow plows or similar implements to install drainage

ditches to allow the passage of surface and subsurface water. If necessary, drain water with

underground outlets installed up gradient of the barrier. 

• Perform pest control with techniques and pesticides that will not significantly damage the vegetative

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barrier. 

• Fill and replant washouts or rills that developimmediately. Fill gaps in established barriers with

transplanted plant material. 

REFERENCES 

Dabney, S.M., Z. Liu, M. Lane, J. Douglas, J. Zhu and D. C. Flanagan. 1999. Landscape benching from

tillage erosion between grass hedges. Soil Tillage Res. 51:219-231. 

Dewald, C., J. Henry, S. Bruckerhoff, J. Ritchie, D. Shepard, J. Douglas, and D. Wolfe. 1996. Guidelines

for the establishment of warm season grass hedge for erosion control. J. Soil Water Conserv. 51(1):16-20. 

Douglas, J.L., and C.E. Mason. 1996. An alternative erosion control practice for cropland. USDA NRCS

Jamie L. Whitten Plant Materials Center Progress Report. 12(7). 

Dunn, G.H., and S.M. Dabney. 1996. Modulus of elasticity and moment of inertia of grass hedge stems.

Trans. American Society of Agricultural and Biological Engineers 39(3):947-952. 

USDA Natural Resources Conservation Service. 2020. Plant Materials Technical Note No. 6: Selecting,

Planting, and Managing Grasses for Vegetative Barriers. USDA, NRCS, National Plant Materials Program,

Washington, D.C

https://www.nrcs.usda.gov/Internet/FSE_PLANTMATERIALS/publications/natpmtn13722.pdf

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