Vegetative Barrier (601) –Vetiver Grass

Conservation Practice Jobsheet

NRCS, PI

March 2007

Definition

Vegetative barriers are permanent strips of stiff, dense vegetation along the general contour of slopes or across concentrated flow areas.

Purpose

Vegetative barriers provide erosion control on cropland and offer an alternative to terraces where the soil might be degraded by terracing.

Vegetative barriers can be used for the following purpose(s):

  • Reduce sheet and rill erosion.
  • Reduce ephemeral gully erosion.
  • Manage water flow.
  • Stabilize steep slopes.
  • Trap sediment.

Conditions Where Practice Applies

This practice applies to all eroding areas, including but not limited to: cropland, pastureland, rangeland, forestland, farmsteads, mined land and construction sites.

This practice applies only when used in conjunction with other conservation practices as part of a conservation management system.

NRCS, PI

March 2007

NRCS, PI

March 2007

Vegetative Barrier – Vetiver Grass601 – Page 1 of 6
FOTG Section IV Jobsheet

Vetiver Grass

Vetiver (Vetiveria zizanioides L. syn..Chrysopogon zizanioides), a tropical grass,has been used throughout the world as a low cost and effective system for soil and water conservation.

Vetiver will form a dense hedge that will slow down runoff, which reduces erosion by causing more water to be absorbed into the soil and by spreading the water out. The thick hedges also trap sediment and over time create terrace-like benches. The deep, thick roots help to stabilize steep slopes and areas experiencing undercutting.

Vetiver can grow in a wide range of conditions. Once established it can tolerate drought and is recommended for areas with an annual rainfall of at least 18 inches. It grows best in areas with high rainfall and can tolerate long periods in waterlogged soils. It is resistant to most pests, diseases and nematodes.

Variance for Use of Vetiver Grass

The Pacific Islands Area (PI) has received a variance to use vetiver grass as a vegetative barrier with specific criteria for establishment.

The vetiver cultivars Sunshine and Monto may be used anywhere in the Pacific Islands Area because these cultivars do not produce seed that sprout. Use of planting material from the vetiver found on the American Samoan island of Aunu'u will only be allowed on that island, since it produces seeds that do sprout.

Plans and Specifications

The following section of this Jobsheet includes site-specific installation and operation and maintenance information for the client to use, if the client is planning to use vetiver. If the client is planning to use any other plant, the generic Vegetative Barrier Jobsheet should be used instead of this one. The site-specific information will be prepared in accordance with the NRCS Vegetative Barrier (601) Conservation Practice Standard.

NRCS, PI

March 2007

Vegetative Barrier – Vetiver Grass601 – Page 1 of 6
FOTG Section IV Jobsheet

NRCS, PI

March 2007

Vegetative Barrier – Vetiver Grass601 – Page 1 of 6
FOTG Section IV Jobsheet

Vegetative Barrier – Vetiver Grass Jobsheet
Prepared for: / Client and/or Business Name:
Owner or Operator:
Treatment Unit Name: / Treatment Unit Size (acres):
Prepared by: / Name: / Date:

Purpose of Applying Practice

Primary Purpose:
Other Purposes:
Plant Material
Vetiver cultivar to be planted:
Obtain sterile planting material from a reliable source. Sections of mature grass clumps should be dug out and split up into slips consisting of at least 3 tillers. Trim the slips to end up with grass tops about 8 inches long. Roots must be at least 2 inches long. The slips can be stored with the roots immersed in water for up to a week, otherwise they need to be planted within 48 hours of being dug up.
Vetiver is not shade tolerant and needs to be planted in areas with full sun. The slips need to be well watered when planted, so the planting time should be scheduled when rainfall is plentiful or when irrigation can be provided.
Additional requirements, if any:
Layout
(from top of field going down) / Strip #(s): / Strip #(s): / Strip #(s): / Strip #(s): / Total System
A. Barrier length (ft)
B. Rows per barrier (1 or 2)
C. Total feet of rows to be planted (A x B)
D. Spacing between slips (2 – 6 inches)
E. Slips per foot (12 / D)
F. Total number of slips (C x E)
(G)F. Barrier width (minimum 12 inches)
(H) G. Spacing between strips (maximum 12 inches) / N/A
(I) H. Total area (sq ft) (A x ((F + G)/12)))
(J) I.Field slope (%)
(K) J. Gradient along each strip (%)
Temporary Vegetative Barriers (Required if vetiver spacing between slips is more than 6 inches.)
If the supply of vetiver is limited, the spacing may be increased, but to no more that 12 inches between slips. Another type of plant will be established uphill of the vetiver as a temporary vegetative barrier and maintained until such time that the vetiver fills in and is mature. The minimum barrier width of the temporary barrier will be 36 inches or 0.75 times the design vertical interval.
Type of temporary vegetative barrier to be established:
Width of temporary vegetative barrier:
Planting requirements:
Site Preparation
Obstructions, such as trees and debris that interfere with vegetative growth and maintenance, will be removed to improve vegetation establishment and alignment.
Additional requirements, if any:
Berm/Channel Establishment
NO, a berm/channel IS NOT required for each barrier strip becausevetiver WILL NOT be planted for the purpose of reducing sheet and rill erosion or managing water flow.
or
YES, a berm/channel IS required for each barrier strip.
and
A berm/channel already exists for each barrier strip with a minimum height/channel depth of 4 inches.
or
A berm/channel already exists for each barrier strip and will be improved to a minimum height/channel depth of 4 inches.
Or
A berm/channel will be constructed for each barrier strip, as follows:
To construct a berm/channel, first dig a channel immediately upslope of each staked line. Use the soil from the channel to build the berm on the upslope edge of the staked line. Minimum berm height/channel depth will be 4 inches. In areas of concentrated flow the depth may need to be increased to reduce the chance of the barrier washing out. The channels will capture runoff and trap sediment until the vegetative barrier becomes established. Over time the channels will fill in create terrace-like benches.
Where berm/channels are used, a stable conveyance system for control of concentrated runoff must exist in flow areas that receive diverted runoff.
Additional requirements, if any:
Fertilizer Application
Fertilizers applied at planting will help the vetiver become established quickly. Fertilize according to soil test results. If no soil test is available, the recommended fertilizer is di-ammonium phosphate (21-53-0), but 19-19-19 or similar fertilizer can be used. Apply 6.5 lbs for every 100 feet along the contour line.
Type of fertilizer to be applied at planting:
Rate of application:
Additional requirements, if any:
Planting and Moisture Requirements
Holes should be made into the berm of each barrier strip to allow the vetiver slips to be planted at a depth of 4 inches. Place the slips into planting hole making sure that the roots point down, then firm the soil around the slip. If the soil is not already wet, then the slips need to be well irrigated at planting.
At least 2 heavy rain showers per week should provide adequate moisture during the first month. If there is not enough rain, then water the plants at least twice a week for the first 3-4 weeks.
Additional requirements, if any:
Temporary Measures
Appropriate temporary measures, such as erosion control blankets, silt barriers or mulches, will be used, as appropriate, during the establishment period.
Requirements for temporary measures, if needed::
Additional Requirements for the Establishment of Vetiver Grass, if any
Operation and Maintenance Requirements
The following actions will be carried out to ensure that this practice functions as intended. These actions include normal activities in the application and use of the practice and repair and maintenance of the practice.
  1. Establishment failures will be replanted immediately. Gaps between plants will be no greater than 3 inches at the end of the first growing season.
  2. To promote tillering, the vetiver will be trimmed to 12-20 inches when it reaches a height of 4 feet. Trim only when there is adequate rainfall or irrigation available. Spread the cut material around the vetiver to help control weeds. The cut material may also be spread in the field to help protect the soil from erosion. Once the barrier is about a foot wide, then trimming is only necessary once a year.
  3. Weeds, especially vines, such as mile-a-minute, will be controlled so that they do not shade out the vetiver. Mulch around the barriers will help control weeds. If using an herbicide, be sure to use one that will not affect grasses or carefully use a wick to apply the herbicide to the weeds. Ask the local agricultural extension agent for assistance in selecting an herbicide to use.
  4. The vetiver will be protected from herbicide used in the cropped field.
  5. Crop tillage and planting operations will be parallel with the vegetative barrier.
  6. Pest control in adjacent fields will be performed with techniques and pesticides that will not damage the vegetative barrier.
  7. Washouts or rills that develop will be filled and replanted immediately. Short gaps in established barriers will be reestablished with transplanted plant material.
  8. Vegetative barriers will not be used as a field road or turn row. Vegetative barriers in concentrated flow areas will not be crossed with machinery.
  9. Vegetative barriers will not be crossed with water furrow plows or similar implements to cut drainage ditches to allow the passage of surface and subsurface water. If necessary, water will be drained with underground outlets installed up gradient of the barrier.
  10. Vetiver barriers will be protected from livestock grazing and all types of traffic until they are well established.
  11. In infertile soils supplemental fertilization of vetiver will be required at least twice a year for the first few years. Fertilize according to soil test results and recommendations. The recommended fertilizer is di-ammonium phosphate (21-53-0), but 19-19-19 or similar fertilizer can be used if no soil test is available. Apply 6.5 lbs for every 100 feet along the contour line. Soils with good fertility usually only need an application of 3.3 lbs per 100 feet a few months after planting.

Additional operation and maintenance requirements, if any:

NRCS, PI

March 2007

Vegetative Barrier – Vetiver Grass601 – Page 1 of 6
FOTG Section IV Jobsheet

Vegetative Barrier – Vetiver Grass Job Sketch

Field sketch showing field boundaries, barrier widths, runoff direction arrow, and field layout. Other relevant information, such as adjacent field conditions including structures, crop types, and complementary practices, may also be included.

Scale 1"= / ft. (NA indicates sketch not to scale: grid size=1/2" by 1/2")

The United States Department of Agriculture (USDA) prohibits discrimination in its programs on the basis of race, color, national origin, sex, religion, age, disability, political beliefs and marital or familial status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication program information (Braille, large print, audiotape, etc.) should contact the USDA Office of Communications (202) 720-2791.

To file a complaint of discrimination write USDA, Director, Office of Civil Rights, Room 326-W, Whitten Building, 14th and Independence Avenue, SW, Washington, DC 20250-9410 or call (202) 720-5964 (voice or TDD). USDA is an equal opportunity provider and employer.

NRCS, PI

March 2007