2-Telfair County DSR-5042-010 RFP Appendix A-Specifications.pdf

APPENDIX A

United States Department of Agriculture -CPS-1326

NRCS, GA

October 2023

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.

USDA is an equal opportunity provider, employer, and lender.

Natural Resources Conservation Service

CONSERVATION PRACTICE STANDARD

CLEARING AND SNAGGING

CODE 326

(ft)

DEFINITION

Removal of specified vegetation along the bank (clearing) and selective removal of snags, drifts, or other obstructions (snagging) from natural or improved streams (includes channels).

PURPOSE

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

Restore flow capacity and direction to prevent and/or reduce ponding and flooding •

Prevent and or reduce excessive bank erosion •

Prevent and/or reduce sediment transported to surface water •

Prevent or reduce debris impacts to infrastructure •

CONDITIONS WHERE PRACTICE APPLIES

Any natural or improved stream where the removal of vegetation, trees, brush, and other obstructions is needed to accomplish one or more of the listed purposes.

CRITERIA

General Criteria Applicable to All Purposes

Notify landowner and/or contractor of responsibility to locate all buried utilities in the project area, including drainage tile and other structural measures. The landowner is also required to obtain all necessary permits for project installation prior to construction.

The design must address all modified flow conditions caused by clearing and snagging.

Location

Include the work limits and flow area of the stream in the area to be cleared and snagged. Trees on the bank that are leaning over or other objects that may fall into the stream may be included.

Clearing and snagging may also be used for other areas, such as temporary disposal areas or travelways, required for implementation of this practice.

Capacity

Determine the capacity of the stream, both before and after modification as needed, using NRCS National

Engineering Handbook (NEH) (Title 210), Part 654, Chapter 6, “Stream Hydraulics.” Select a value of

Manning’s “n” roughness coefficient to determine stream capacity after modification that reflects the degree of natural changes and maintenance expected to occur in future years. Other capacity analysis may be performed at the discretion of the design engineer, area engineer, or state engineer.

https://www.nrcs.usda.gov/

Stability

Clearing and snagging activities may affect stream stability. The effect on downstream and upstream reaches due to the removal of obstructions must be analyzed using appropriate stream geomorphologic procedures. Avoid or mitigate activities that negatively affect stability.

Debris disposal

Remove cleared and snagged material from the floodplain or deposit in areas or in a manner that will not significantly affect the flow capacity of the floodplain. Designate proper locations to dispose of all debris including invasive species and where the debris will not remobilize during future flood events.

Hazardous materials

Hazardous materials such as propane tanks and car bodies may be part of the debris that is to be removed. The contractor will investigate the debris in the work limit area prior to and during removal to ensure that all work is performed in a safe manner and hazardous debris is properly disposed of.

Vegetation

Restore all areas denuded and/or disturbed during clearing and snag removal by planting vegetation, unless the disturbance is minimal and conditions are highly conducive for natural regeneration of vegetation. Use native vegetation where practical. Vegetation established as part of this practice should include ecologically suitable species obtained from local sources wherever practical. Take precautions to prevent introduction of invasive species.

Minimize disturbance of wetlands, riparian areas, and fish and wildlife habitat sites, and avoid disturbance where possible.

The establishment of vegetation on cleared and snagged areas will be in accordance with the criteria contained within NRCS Conservation Practice Standard (CPS) Critical Area Planting (Code 342).

CONSIDERATIONS

Debris in stream systems affects the physical characteristics of the stream as well as the diversity and abundance of its aquatic organisms. Fisheries and/or aquatic biologists can assist in evaluating and incorporating measures to improve aquatic and riparian-wetland habitat.

Incorporate enhancements for fish and wildlife values as needed and practical. Special attention should be given to landscape aesthetics and to protecting and maintaining key shade, food, and den trees. Use

NRCS CPS Stream Habitat Improvement and Management (Code 395).

In addition to NRCS CPS Critical Area Planting (Code 342), for areas where it is difficult to establish vegetation consider NRCS CPSs Riparian Herbaceous Cover (Code 390), Riparian Forest Buffer (Code

391), Access Control (Code 472), Mulching (Code 484), Streambank and Shoreline Protection (Code

580), and Tree/Shrub Establishment (Code 612).

Retain habitat-forming elements that provide cover, food, pools, and water turbulence, to the extent possible.

Root balls of fallen trees that are securely anchored in the stream or naturally formed logjams may provide fish habitat and/or stability. The effects of these items should be included in the stream capacity hydraulic analysis. Existing root structure and stumps firmly within the soil should remain to help stabilize the soil and facilitate resprouting of woody vegetation.

Erosion rates decline as a percentage of vegetative roots in a streambank increases. Selection of appropriate riparian vegetation will increase the streambank’s ability to resist future erosion.

Clearing and snagging activity may resuspend sediments in the flow. Consider techniques that promote beneficial sediment deposition and the filtering of sediment.

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October 2023

During construction, woody materials may float downstream and cause additional snags and drifts.

Incorporate measures as needed and practical to address this concern.

Schedule in-stream work to avoid environmentally sensitive periods such as spawning and migration to the fullest extent possible.

Incorporate measures and practices, as needed and practical, to address modified flow conditions that adversely affect resources such as—

A lowered hydraulic gradient that may drain adjacent flood plains more quickly. •

Decreased ground water recharge in water-losing streams resulting from reduced residence time in • the stream and adjacent floodplains.

Ground-disturbing activities associated with this practice have the potential to adversely affect protected plant species and may encourage the establishment of invasive plant species. Quickly revegetating disturbed areas can minimize the introduction of nonnative species.

Temporary erosion and sediment best management practices can be used to minimize the delivery of fine sediment to adjacent and downstream reaches.

Incorporate construction methods that enhance fish and wildlife values as needed and practical to include—

Use of hand-operated equipment, water-based equipment, or small equipment to minimize soil, • water, and other resource disturbances.

Operation of heavy machinery from atop adjacent streambanks to the fullest extent possible. •

After the material has been removed from streambank locations, limiting machinery access to • riparian areas to minimize damage to stream habitat.

No special considerations have been identified for this practice.

PLANS AND SPECIFICATIONS

Prepare plans and specifications for clearing and snagging that describe the requirements for applying the practice to achieve its intended purpose(s).

As a minimum, include, as applicable, the following items in the plans and specifications:

Map of overall area including work limits and limits of clearing and snagging required. •

Location of ingress and egress to the site. •

Description of works of improvement, extent of removal, and manner of disposal. •

Location of disposal areas or location of areas off limits for disposal of debris. •

Requirements for stabilization and vegetation in disturbed areas. •

Location and description of trees or vegetation to be left undisturbed. •

Manner and sequence of construction operations so that impacts on the environment will be • minimized.

Hazardous material identification procedure. •

Erosion control measures, as applicable. •

Carry out all operations in a safe and skillful manner. Observe all safety and health regulations and use appropriate safety measures.

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October 2023

OPERATION AND MAINTENANCE

Provide an operation and maintenance plan to the landowner/user to maintain stream capacity and vegetative cover. Items to include are—

Assessing the area after each major storm event for downed trees and debris accumulation. •

Remove or relocate and anchor downed trees and debris accumulations that are causing bank erosion problems as soon as possible.

Periodically inspecting the area for signs of streambank undermining or instability. Remove any • debris accumulations that may contribute to the instability and closely monitor the area.

Clearing any vegetation and/or debris that blocks side drainage structures and streams. •

Promptly repair eroded areas. •

Maintain companion conservation practices to NRCS specifications. •

REFERENCES

USDA NRCS. 2007. National Engineering Handbook (Title 210), Part 654, Stream Restoration Design.

Washington, D.C. https://directives.sc.egov.usda.gov/

USDA NRCS. 2009. National Biology Handbook (Title 190), Part 614.00, Stream Visual Assessment

Protocol Version 2. Washington, D.C. https://directives.sc.egov.usda.gov/

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October 2023 https://directives.sc.egov.usda.gov/ https://directives.sc.egov.usda.gov/

NRCS, GA SPECIFICATION - Page 1 of 3 October 2023

Practice Specification

Clearing and Snagging (Code 326)

1. Scope

The work consists of providing all equipment, materials, labor, and overhead for clearing, snagging, removal, and disposal of woody vegetation from the stream (includes channel) streambank, and other designated areas in accordance with these specifications, the construction drawings, or as staked in the field.

2. Construction Operations

The landowner is responsible for obtaining all necessary local, Tribal, State and Federal permits.

Site ingress and egress routes will be shown on the drawings or staked in the field. Removal or damage to riparian trees and vegetation will be minimized. Once the designated routes have been established, equipment and vehicular travel over other areas will be avoided.

No construction equipment will be operated below the existing water surface except in specific circumstances as noted in Section 10 of this specification.

All construction activities will be performed in a skillful and workmanlike manner and must conform to the lines, grades and elevations shown on the drawings or as staked in the field. The completed work shall have a neat appearance.

All temporary measures such as culverts, cofferdams, or silt fences specified or shown on the drawings must be completely removed at the conclusion of construction.

3. Workmanship

All construction activities must be performed in a skillful and workmanlike manner and shall conform to the lines, grades and elevations shown on the drawings or as staked in the field. The completed work will have a neat appearance. Control of all construction activities in accordance with the specifications and drawings will be the responsibility of the landowner and contractor.

All operations will be carried out in a safe manner. Safety and health regulations will be followed and appropriate safety measures taken.

4. Utilities

Landowners or operators, sponsoring organizations, and/or contractors will be liable for damage to utilities and damage resulting from disruption of service caused by construction activities.

It is the responsibility of the landowner or contractor to determine if there are buried or overhead utilities in the vicinity of the proposed work. The contractor is required to call (811) or contact the state utilities locator service website for utilities to be located prior to commencing construction. They must follow proper procedures to ensure that the utilities are not jeopardized and that equipment operators and others will not be injured during construction operations. They will conduct all work and operations in accordance with the proper safety codes for the types of construction being performed with due regard to the safety of all persons and property.

The Natural Resources Conservation Service (NRCS) makes no representation on the existence or non-existence of any utilities. Absence of utilities on the drawings is not assurance that no utilities are present at the site.

5. Pollution and Erosion Control

Construction operations will be conducted to minimize erosion and air and water pollution, holding them within legal limits as required by any required permits. Fuel and oil storage and transfer will be conducted away from the streambank. Fuel and oil spills must be cleaned up and handled in accordance with any permits. Specific pollution and erosion control measures applicable to the site will be described in the site

Stormwater Pollution Prevention Plan, if required, and in Section 10 of this specification.

Natural Resources Conservation Service

6. Clearing and Snagging

Unless otherwise shown on the drawings or marked in the field, all down trees, logs, drifts, debris, and other obstructions lying wholly or partially within the work area of the stream must be removed. Piling, piers, headwalls, and sediment bars within the work area that obstruct the free flow of water must be removed when so designated.

Selective snagging, where possible, must be performed primarily with hand-operated equipment, water-based equipment, or small equipment used in a manner that will minimize soil, water, and other resource disturbance.

Clear all logs, stumps, brush, trees, and rubbish not marked for preservation from within the limits of the work area. Trees and other vegetation to remain undisturbed will be marked or designated as described in Section 10 of this specification.

Trees, stumps, and brush within the stream perimeter will be cut as close to the ground as the cutting equipment permits. In other areas to be cleared, the trees brush and other vegetation will be cut within the maximum distance from the ground level specified in Section 10 of this specification.

Trees will be felled in a safe manner that avoids damage to trees, property, or other objects outside the work area or otherwise designated to be undisturbed.

Cut stumps and root wads on the streambank must remain undisturbed to minimize soil disturbance ands erosion. Where designated, sound logs will be placed against banks and anchored to serve as bank protection and/or fish habitat. The placement location and anchoring details of such logs will be shown on the drawings.

If herbicide treatment is planned, the stumps and brush in the designated area must be treated at the time of clearing according to the recommendations of the herbicide manufacturer.

The use of explosives in clearing and snagging operations, when allowed, must be in strict accordance with applicable State statutes and regulations.

7. Disposal

Burn, bury, or pile trees, logs and other combustible material from the clearing and snagging operations in the location and manner shown on the drawings. All burning, if allowed, must occur outside the stream and be in accordance with local, Tribal, and State regulations. Bury residue from burning and noncombustible material in the designated disposal area(s) outside the stream and provide adequate soil cover, but not less than the depth specified in Section 10 of this specification. Disposal of trash and garbage such as rubber, plastic, glass, and metal must be taken to an approved waste disposal area.

After burning and disposal, uniformly grade the areas to drain to the surrounding, undisturbed area. The finished areas must be suitable for the land use of the adjacent land.

8. Vegetation

Shape the area within and adjacent to the clearing and snagging work limits to blend with the surrounding land. The shaped area must drain or divert overland runoff from the work area without excess soil erosion. All disturbed areas will be mulched, fertilized, and seeded in accordance with CPS 642, Critical

Area Planting unless otherwise specified in Section 10 of this specification.

9. Final Inspection and Acceptance

NRCS will periodically review the work for the benefit of the agency. NRCS will make a final construction checkout for acceptance

NRCS may periodically review the work to ensure the work complies with the specifications and drawings.

Upon completion of the work, the installation will be subjected to a final inspection. All work will be complete, cleaned and ready for use. All work must meet the requirements as to line, grade, cleanliness and workmanship. All discrepancies must be repaired. The work will be accepted and certified only after the final inspection and satisfactory completion of all items not in compliance.

NRCS, GA October 2023SPECIFICATION - Page 2 of 3

United States Department of Agriculture -CPS-1342

October 2018

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.

USDA is an equal opportunity provider, employer, and lender.

Natural Resources Conservation Service

CONSERVATION PRACTICE STANDARD

CRITICAL AREA PLANTING

CODE 342

(ac)

Establishing permanent vegetation on sites that have, or are expected to have, high erosion rates, and on sites that have physical, chemical, or biological conditions that prevent the establishment of vegetation with normal seeding/planting methods.

PURPOSE

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

Stabilize areas with existing or expected high rates of soil erosion by wind or water •

Stabilize stream and channel banks, pond and other shorelines, earthen features of structural • conservation practices

Stabilize areas such as sand dunes and riparian areas •

CONDITIONS WHERE PRACTICE APPLIES

This practice applies to highly disturbed areas such as—

Active or abandoned mined lands. •

Urban restoration sites. •

Construction areas. •

Conservation practice construction sites. •

Areas needing stabilization before or after natural disasters such as floods, hurricanes, tornados, • and wildfires.

Eroded banks of natural channels, banks of newly constructed channels, and lake shorelines. •

Other areas degraded by human activities or natural events. •

CRITERIA

General Criteria Applicable to All Purposes

Site preparation

Conduct a site investigation to identify any physical, chemical, or biological conditions that could affect the successful establishment of vegetation.

Clear areas to be planted of unwanted materials and smooth or shape, if needed, to meet planting purpose(s).

Prepare a suitable seedbed for all seeded species. Rip compacted layers and re-firm the soil prior to seedbed preparation, as needed.

As site conditions dictate, when grading slopes, stockpile topsoil to be redistributed over area to be planted.

Species selection

Select species for seeding or planting that are suited to local site conditions and intended uses, and common to the site or location.

Selected species will have the capacity to achieve adequate density and vigor to stabilize the site within an appropriate period.

Establishment of vegetation.

Plant seeds using the method or methods best suited to site and soil conditions.

Limit sod placement to areas that can naturally supply needed moisture or sites that can be irrigated during the establishment period. Place and anchor sod using techniques to ensure that it remains in place until established.

Specify species, rates of seeding or planting, legume inoculation, minimum quality of planting stock (e.g., pure live seed (PLS) or stem caliper), method of seedbed preparation, and method of establishment before application. Use only viable, high-quality seed or planting stock.

Seed or plant at a time and in a manner that best ensures establishment and growth of the selected species.

Plant during approved times for the species to be used.

Apply soil amendments (e.g., lime, fertilizer, compost) according to the requirements in the local Field

Office Technical Guide.

Mulch or otherwise stabilize (e.g., polyacrylamide (PAM)) plantings as necessary to ensure successful establishment.

Additional Criteria to Stabilize Stream and Channel Banks, Pond and Other Shorelines, Earthen

Features of Structural Conservation Practices

Bank and channel Slopes

Shape channel side slopes so that they are stable and allow establishment and maintenance of desired vegetation.

A combination of vegetative and structural measures may be necessary on slopes steeper than 3:1 to ensure adequate stability.

Species selection.

Plant material used for this purpose must—

Be adapted to the hydrologic zone into which they will be planted. •

Be adapted and proven in the regions in which they will be used. •

Be compatible with existing vegetation in the area. •

Protect the channel banks but not restrict channel capacity. •

Establishment of vegetation.

Specify species, planting rates, spacing, methods and dates of planting based on local planting guides or technical notes.

Identify and protect desirable existing vegetation during practice installation.

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Use a combination of vegetative and structural practices with living and inert material when flow velocities, soils, and bank stability preclude stabilization by vegetative establishment alone. Use Conservation

Practice Standard (CPS) Streambank Stabilization (Code 580) for the structural measures.

Control existing vegetation on a site that will compete with species to be established vegetatively (e.g..

bare-root, containerized, ball-and-burlap, potted) to ensure successful establishment of the planted species.

Plant streambank stabilization vegetation in accordance with the NRCS Engineering Field Handbook Part

650, Chapter 16, “Streambank and Shoreline Protection,” and Chapter 18, “Soil Bioengineering for Upland

Slope Protection & Erosion Reduction.”

Site protection and access control.

Restrict access to planted areas until fully established.

Additional Criteria to Stabilize Areas Such As Sand Dunes and Riparian Areas

Plants for sand dunes and coastal sites must be able to survive being buried by blowing sand, sand blasting, salt spray, salt water flooding, drought, heat, and low nutrient supply.

Include sand trapping devices such as sand fences or brush matting in the revegetation/stabilization plans where applicable.

CONSIDERATIONS

Species or diverse mixes that are adapted to the site and have multiple benefits should be considered.

Native species may be used when appropriate for the site.

To benefit pollinators and other wildlife, flowering shrubs and wildflowers with resilient root systems and good soil-holding capacity also should be considered for incorporation as a small percentage of a larger grass-dominated planting. Where appropriate consider a diverse mixture of forbs to support pollinator habitat.

Planning and installation of other CPSs such as Diversion (Code 362), Obstruction Removal (Code 500), Subsurface Drain (Code 606), Underground Outlet (Code 620), or Anionic Polyacrylamide Application

(Code 450) may be necessary to prepare the area or ensure vegetative establishment.

Areas of vegetation established with this practice can create habitat for various type of wildlife.

Maintenance activities, such as mowing or spraying, can have detrimental effects on certain species.

Perform management activities at the times and in a manner that causes the least disruption to wildlife.

PLANS AND SPECIFICATIONS

Prepare plans and specifications for each field or management unit according to the criteria and operation and maintenance sections of this standard. Record practice specifications using approved Implementation

Requirements document.

Address the following elements in the plan, as applicable, to meet the intended purpose(s):

Practice purpose(s) •

Site preparation •

Topsoil requirements •

Fertilizer application •

Seedbed/planting area preparation •

Timing and method of seeding/planting •

Selection of species •

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Seed/plant source •

Seed analysis/pure live seed (PLS) •

Seeding rate/plant spacing •

Mulching, PAM, or other stabilizing materials •

Supplemental water needed for establishment •

Protection of plantings •

Describe successful establishment (e.g., minimum percent ground/canopy cover, percent survival, • stand density)

OPERATION AND MAINTENANCE

Control access to the area to ensure the site remains stable. •

Protect plantings shall be protected from pests (e.g., weeds, insects, diseases, livestock, or wildlife) • as necessary to ensure long-term survival.

Inspections, reseeding or replanting, and fertilization may be needed to ensure that this practice • functions as intended throughout its expected life.

Observe establishment progress and success at regular intervals until the practice has met the • criteria for successful establishment and implementation.

Description of successful establishment (e.g., minimum percent ground/canopy cover, percent • survival, stand density).

REFERENCES

Federal Interagency Stream Restoration Working Group. 1998. Stream corridor restoration: principles, processes, and practices. USDA NRCS National Engineering Handbook, Part 653.

USDA NRCS. 2007. National Engineering Handbook, Part 654. Stream restoration guide.

USDA NRCS. 2015. The PLANTS Database (http://plants.usda.gov, 8 December 2015). National Plant

Data Team, Greensboro, NC.

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United States Department of Agriculture -CPS-1484

October 2018

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.

USDA is an equal opportunity provider, employer, and lender.

Natural Resources Conservation Service

CONSERVATION PRACTICE STANDARD

MULCHING

CODE 484

(ac)

Applying plant residues or other suitable materials to the land surface.

PURPOSE

This practice is applied to achieve the following purpose(s):

Improve the efficiency of moisture management •

Reduce irrigation energy used in farming/ranching practices and field operations •

Improve the efficient use of irrigation water •

Prevent excessive bank erosion from streams, shorelines, or water conveyance channels •

Reduce concentrated flow erosion •

Reduce sheet, rill, and wind erosion •

Improve plant productivity and health •

Maintain or increase organic matter content •

Reduce emisions of particulate matter •

CONDITIONS WHERE PRACTICE APPLIES

This practice applies to all lands where mulches are needed.

CRITERIA

General Criteria Applicable to All Purposes

The selection of mulching materials will depend primarily on the purpose(s) for the mulch application, site conditions, and material availability. The mulch materials may consist of natural or synthetic materials of sufficient dimension (depth or thickness) and durability to achieve the intended purpose for the required time period.

Prepare the soil surface to achieve the desired purpose.

Apply the mulch material evenly. Use tackifiers, emulsions, pinning, netting, crimping, or other methods of anchoring, if needed, to hold the mulch in place for specified periods.

In cases where furrow erosion may occur due to concentrated flows from mulches(e.g., plastic mulches on beds), take appropriate measures to protect the furrows and the furrow outlets.

Apply manufactured mulches according to the manufacturer’s specifications.

Remove synthetic mulches from the field prior to the next crop. Do not incorporate (e.g. disk) synthetic mulches a into the soil.

https://www.nrcs.usda.gov/

When mulching with wood products such as wood chips, bark, or shavings or other wood materials, apply a minimum 2-inch thickness of particles that remain in place during heavy rainfall or strong wind events, or both if applicable.

The minimum size of mulching material consisting of gravel or other inorganic mulching is 0.75 inches and applied to a minimum depth of 2 inches.

When mulching with cereal grain straw or grass hay, apply at a rate to achieve a minimum 70 percent ground cover. Determine the mulch rate using the current erosion prediction technology for the intended purpose.

Do not apply plant-based mulch materials with a carbon (C) to nitrogen (N) ratio of less than 20:1 to watercourses.

Additional Criteria to Improve the Efficiency of Moisture Management, to Reduce Irrigation Energy

Used in Farming/Ranching Practices, and Field Operations or to Improve the Efficient Use of Irriga-tion Water

Apply mulch materials to cover at least 90 percent of the soil surface to reduce potential evaporation.

Fine textured mulches (e.g., rice hulls) which allow less oxygen penetration than coarser materials should be no thicker than 2 inches

Additional Criteria to Improve Plant Productivity and Health

When establishing vegetative cover, apply mulch at a rate that achieves a minimum of 70 percent ground cover to provide protection from erosion and runoff and yet allow adequate light and air penetration to the seedbed to ensure proper germination and emergence.

Additional Criteria to Increase Organic Matter Content

Use plant-based mulching materials of suitable quantity and quality to add organic matter, provide food and shelter for soil biota, and protect the soil surface from raindrop impact and crusting, while allowing for adequate soil aeration.

An evaluation of the system using the current approved soil conditioning index (SCI) procedure results in zero or higher.

CONSIDERATIONS

Evaluate the effects of mulching on evaporation, infiltration, and runoff. Mulch material may affect microbial activity in the soil surface, increase infiltration, and decrease runoff, erosion, and evaporation.

The temperature of the surface runoff may also be lowered.

Mulch materials with low permeability may adversely affect the water needs of plants.

Avoid excessively thick or tightly packed mulches that can result in soggy anaerobic conditions at the soil surface during wet weather, or prevent rainfall or overhead irrigation from reaching the soil during times of moisture deficit.

Organic materials with C:N ratios of less than 20:1 will release nitrate-nitrogen that can cause water quality impairments.

Finely divided plant residues (e.g., sawdust) and those rich in soluble carbohydrates (e.g., fresh green-chopped sorghum-sudangrass, corn, or other grasses) that have a C:N ratio greater than 30 can tie up soil N and necessitate supplemental N applications on crops. Coarser materials such as grain straw and chipped brush usually do not reduce crop-available soil N levels unless and until they are incorporated into the soil by tillage or cultivation.

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Mulching may also provide habitat for beneficial organisms and provide pest suppression.

In attempting to provide habitat for ground beetles,spiders, and other predators of weed seeds and crop pests, use mulch ofsufficient ground cover and suitable thickness and texture for the targetspecies. Avoid excessively thick ortightly packed mulches, which can interfere with the movement of ground beetlesand other beneficial organisms, and may increase the incidence of crop pestsand diseases. Consider mulching cropsonly if the selected mulching materials, and rates of application do not contributeto pest problems.

During the period when weed seed predation is desired and predators are most active, avoid pesticide applications or pesticide exposures that could adversely affect weed seed consumers.

Low permeability mulches (e.g., plastic) may increase concentrated flow and erosion on unmulched areas.

Light-reflecting mulches such as white or aluminized plastic film or bright straw can repel some pests.

Consider potential beneficial or detrimental effects of mulching materials on the biotic community surrounding the crop, including beneficial soil micro- and macro-organisms, as well as plant pathogens and plant pests. These effects are specific to site, mulch, and crop, and may include enhanced soil microbial activity, increased or reduced levels of crop diseases, and toxic (allelopathic) activity against the crop, weeds, or other beneficial or pest organisms.

Keep mulch 3 to 6 inches away from plant stems and crowns to prevent disease and pest problems.

Additional weed control may be needed around the plant base area.

Deep mulch provides nesting habitat for ground-burrowing rodents that can chew extensively on tree trunks and tree roots. Light mulch applied after the first cold weather may prevent rodents from nesting.

Some mulch material may adversely affect aquatic environments through changes in water chemistry or as waterborne debris. Consider placing mulch in locations that minimizes these risks.

Consider potential effects of soil physical, chemical and biological properties. Refer to soil survey data as a preliminary planning tool for assessment of areas. Consult a resource soil scientist or the Web Soil

Survey at: http://websoilsurvey.nrcs.usda.gov/app/ to obtain soil properties and qualities information.

For all organic or transitioning to organic operations, follow all National Organic Program (NOP) rules.

PLANS AND SPECIFICATIONS

Prepare specifications for each site and purpose on the approved implementation requirements documentation. Documentation must include—

Purpose of the mulch. •

Type of mulch material used. •

Percent cover or thickness of mulch material, as applicable. •

Timing of application. •

Site preparation. •

Listing of netting, tackifiers, or method of anchoring. •

Operation and maintenance. •

OPERATION AND MAINTENANCE

Periodically inspect the mulched areas and reinstall mulch or repair as needed to accomplish the intended purpose.

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October 2018 http://websoilsurvey.nrcs.usda.gov/app/

Evaluate the effectiveness of the mulch (application, amount of cover provided, durability, etc.) and adjust the management or type of mulch to better meet the intended purpose(s).

Remove or incorporate mulch materials will be consistent with the intended purpose and site conditions.

Do not operate equipment near the mulched site that would compromise the intended purpose of the mulch.

Prevent or repair any fire damage to the mulch material.

Properly collect and dispose of synthetic mulch material after intended use.

Monitor and control undesirable weeds in mulched areas.

REFERENCES

Agriculture and Agri-Food Canada. 2000. Plastic mulches for commercial vegetable production. Canada-

Saskatchewan Irrigation Diversification Centre. Outlook, Saskatchewan.

Flanagan, D.C., Nearing, M.A. USDA-Water Erosion Prediction Project, Hillslope Profile and Watershed

Model Documentation, NSERL Report #10, July 1995.

Renard, K.G., G.R. Foster, G.A. Weesies, D.K. McCool, and D.C. Yoder, Coordinators. 1997. Predicting soil erosion by water: A guide to conservation planning with the Revised Universal Soil Loss Equation

(RUSLE). U.S. Department of Agriculture, Agriculture Handbook No. 703.

Shaffer, M.J., and W.E. Larson (ed.). 1987. NTRM, a soil-crop simulation model for nitrogen, tillage and crop residue management. USDA Conserv. Res. Rep. 34-1. USDA-ARS.

Toy, T.J., and G.R. Foster. (Ed.) 1998. Guidelines for the use of the Revised Universal Soil Loss Equation

(RUSLE) Version 1.06 on mined lands, construction sites, and reclaimed lands. USDI, OSMR.

USDA, NRCS. 2011. National Agronomy Manual. 190-V, 4th Ed. Washington, D.C.

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