US Army Corps of Engineers
Cold Regions Research and
Engineering Laboratory
Hanover, New Hampshire  03755-1290



  Guidelines for Managing Vegetation on Earth-Covered Magazines
              Within the U.S. Army Materiel Command


    Antonio J. Palazzo, Lawrence W. Gatto and William Woodson
                                
                           August 1994



                          Prepared for

                      ARMY MATERIEL COMMAND
               INSTALLATIONS AND SERVICES ACTIVITY
                ROCK ISLAND, ILLINOIS 61299-7190






ABSTRACT

     The purpose of these guidelines is to assist land managers
in establishing and maintaining vegetation on earth-covered
magazines (ECMs) in a safe, efficient and cost-effective manner.
Although the vegetation management procedures discussed here are
intended primarily for conventional storage ECMs, not those used
for special weapons, many of the general procedures and
principles presented apply to both types.  In humid areas a
healthy vegetative cover on ECMs is the primary factor in
maintaining the stable soil cover that is required to meet safety
standards.  Thus, a vegetation management planning process is
presented that assists land managers in defining management
goals, assessing climatic and soil factors and evaluating
vegetation options.  Specific methods and procedures that have
proven successful for maintaining and reestablishing an effective
vegetation cover are outlined.  Other methods used to stabilize
the ECM soil cover in dry climates, where cost-effective
maintenance of vegetation can be difficult to impossible, are
briefly discussed as well.




PREFACE

     This report was prepared by Antonio J. Palazzo, Research
Agronomist, Geochemical Sciences Branch, Lawrence W. Gatto,
Research Geologist, Geological Sciences Branch, Research
Division, U.S. Army Cold Regions Research and Engineering
Laboratory; and William Woodson, Forester, Army Materiel Command
Installations and Services Activity, Rock Island, Illinois.
     Funding for this work was provided by the Army Materiel
Command (AMC) Installations and Services Activity, Rock Island,
Illinois.
     The authors acknowledge the following individuals for their
support in preparing this manuscript: Dean Pidgeon and Ronald
Bailey for assistance in the field research; David Cate for
technical editing; Marilyn Aber for cover design and preparation;
Colonel Knowles, Richard Clewell and Tom Vorak, Installation and
Services Activity, Army Materiel Command, Rock Island, Illinois,
for funding support and for technical reviews.  The authors thank
the following for additional technical reviews:
     U.S. Army Field Safety Office
     Defense Ammunition Center and School
     Tom Patrick, Headquarters, Department of the Army
     Charles Becker, Pine Bluff Arsenal
     James Purrell, Hawthorne Army Ammunition Plant
     Robert Duell, Rutgers University
     Richard Price, U.S. Army Corps of Engineers Waterways
      Experiment Station
     Gregory S. Heles, Army Technical Center for Explosives
      Safety
     James L. Shadeck, Deputy Chief of Staff for Engineering,
      Depot Systems Command
     CPT Gary Milner, Director of Law Enforcement and Security,
      Bluegrass Army Ammunition Depot
     Emmet Igo, Physical Security Inspector, Bluegrass Army
      Ammunition Depot
     Melvin Barnet, Chief, Buildings and Grounds, Bluegrass Army
      Ammunition Depot
     Rick Garner, Safety Officer, Bluegrass Army Ammunition Depot
     Billye Hazlett, Land Manager, Bluegrass Army Ammunition
      Depot
     Sal Marici, Soil Conservationist, Army Armament, Munitions
      and Chemical Command
     Wolfgang Grimm, Forester, U.S. Army, Europe
     Dave Self, Environmental Coordinator, Lonestar Army
      Ammunition Plant
     Basil Kirby, Pest Controller, Letterkenny Army Depot
     Ken Davis, Safety Office, Depot Systems Command
     Robert Klein, Army Materiel Command Field Safety Office
     Wayne Fordham, Air Force Natural Resources Management.

     The contents of this report are not to be used for
advertising or promotional purposes.  Citation of brand names
does not constitute an official endorsement or approval of the
use of such commercial products.



     This report is published in two formats.  One is a CRREL
Report; the other is the user's manual.  This version is designed
to be updated periodically by the users as well as the sponsors.
User input is essential to this process.  If you experience
elements of this guide that simply do not work, please let us
know.  If you have better ideas, let us know.
     While you, the users, are putting these guides to the
ultimate test, we administrators and researchers will be
attempting to further analyze vegetation growth on earth-covered
magazines, procedures to prevent soil slippage, and additional
stabilization techniques for and areas.  We will be able to focus
our work more effectively if we hear from you, the users and
implementers.
     All correspondence should be directed to U.S. Army Materiel
Command, Installations and Services Activity, ATTN:  ANIXEN-M,
Rock Island, Illinois 61299-7190.  The point of contact is Bill
Woodson, Defense Switched Network 793-4062, commercial phone 309-
782-4062 (FAX extension 7566), email woodson@osiris.cso.uiuc.edu
or wew@rja-emh2.army.mil.
     The form below may be used, or use any means you feel is
appropriate.
-----------------------------------------------------------------

To:    AMC, Installations & Services Activity
       ATTN:  AMXEN-M
       Rock Island, Illinois  61299-7190


SUBJECT:  Improvements to Guidelines for Managing Vegetation on
Earth-Covered Magazines Within the U.S. Army Materiel Command


1.   Page number for improvement (ignore if not applicable)

     ____________________________________________________________

2.   Person providing suggestion (Name, address, phone)

     ____________________________________________________________

     ____________________________________________________________

3.   Suggestion for improvement:  _______________________________

     ____________________________________________________________



CONTENTS
                                                             Page
Title page ..................................................   i
Abstract ....................................................  ii
Preface ..................................................... iii
Suggestion form .............................................  iv

I.   Introduction ...........................................   1
     Ia.   Purpose of these guidelines ......................   1
     Ib.   Format of these guidelines .......................   3

II.  Vegetation management planning .........................   3
     IIa.  Assessment of management goals ...................   3
     IIb.  Climatic zones and plant selection ...............   4
     IIc.  Flammability .....................................   5
     IId.  Trees ............................................   5
     IIe.  Soil monitoring ..................................   6

III. Maintenance of existing vegetation on ECMs .............  10
     IIIa. Vegetation maintenance goals .....................  10
     IIIb. Site assessment ..................................  10
     IIIc. Specific maintenance techniques ..................  13
     IIId. Cost/benefit analysis of different techniques ....  31
     IIIe. Evaluating success ...............................  31

IV.  Establishment of vegetation on ECMs ....................  31
     IVa. Goal assessment ...................................  31
     IVb. Site assessment ...................................  31
     IVc. Plant selection ...................................  32
     IVd. Site preparation and seeding ......................  32
     IVe. Evaluating success ................................  34

Appendix A. Land managers at AMC facilities with ECMs .......  39
Appendix B. General and region-specific references ..........  41
Appendix C. Worksheets for developing a revegetation plan ...  45
Appendix D. Techniques for estimating soil erosion ..........  53
Appendix E. Vegetation commonly used for revegetation .......  55
Appendix F. Seed mixture recommendations for individual
              facilities ....................................  59
Appendix G. Plant materials centers, SCS ....................  61


                    **FIGURES & TABLES NOT**
                      **AVAILABLE ON-LINE**

ILLUSTRATIONS

Figure

1. AMC facilities with ECMs .................................   1
2. Steps involved in developing and implementing a
    revegetation management plan ...........................   4
3. General relationship between soil moisture
    characteristics and soil texture .......................   6
4. Soil textural triangle showing the percentages
    of sand, silt and clay in the soil classes
    using USDA definitions .................................   9
5. Influence of percent slope on revegetation ...............  10
6. Steps involved in planning new seedings ..................  32


TABLES

Table

 1. Army documents that govern the maintenance of
     earth-covered magazines ................................   2
 2. Survey responses concerning vegetation management
     problems with ECMs .....................................   2
 3. Soil and climatic conditions increasing the
     likelihood of plant nutrient deficiencies ..............   6
 4. Relative neutralizing value of six common forms of lime .   7
 5. Range of pH for optimum growth of various gases .........   7
 6. Symptoms of nutrient deficiencies in plants .............   8
 7. Methods of correcting certain plant nutrient deficiencies   8
 8. Soil textural classes and general terminology used
     in soil descriptions ...................................   9
 9. Comparisons of maintenance techniques ...................  31
10. Advantages and disadvantages of native vs.
     introduced species .....................................  33
11. Optimum temperatures for seed germination of common
     turfgrass ..............................................  34
12. Nitrogen, phosphorus and potassium carriers that may
     be used for seedbed fertilization ......................  35
13. Approximate N, P, K content of certain natural organic
     fertilizer materials ...................................  36
14. Common fertilizer ratios and some typical fertilizer
     analyses for each ratio ................................  37
15. Performance of various mulches and stabilizers used
     for reestablishing vegetation in undisturbed areas .....  37




              Guidelines for Managing Vegetation on
                     Earth-Covered Magazines
              Within the U.S. Army Materiel Command


              ANTONIO J. PALAZZO, LAWRENCE W GATTO
                       AND WILLIAM WOODSON


*****FIGURES & TABLES NOT*****
     *****AVAILABLE ON-LINE*****
                                

1.   INTRODUCTION

Ia.  Purpose of these guidelines
     About 18,500 earth-covered magazines (ECMs) are under the
jurisdiction of the Army Materiel Command (AMC) at 39
installations in 28 states (Fig. 1).  There are different types
of ECMs, but the Stradley is the most common.  These ECMs are
designed, built and maintained to meet safety and security
requirements as defined in Army and AMC regulations and manuals
(Table 1).  These regulations do not specify standard vegetation
requirements but generalize about vegetation limitations on
conventional weapons magazines.  Therefore, the natural resources
or land manager has wide latitude in using vegetation to ensure
ECM slope stability.
     Because of steep slopes, poor soils, exposure, grazing
animals and other factors, the establishment and maintenance of
vegetation on ECMs is often extremely difficult.  Some of the
more severe problems in vegetation management are shown in Table
2.  Slopes are often too steep for heavy tillage and maintenance
equipment to operate safely, so maintenance-free or low
maintenance vegetation must be used.  In addition, most ECMs were
constructed in the 1940s and 1950s, so the repair, renovation and
revegetation of many of them is needed or underway, making the
need for better, more efficient vegetation management techniques
immediate.
     The establishment and maintenance of an adequate vegetative
cover on ECMs help control soil erosion and thereby maintain the
minimum 2 ft of earth cover required by AMC-R 385-100.  If soil
loss results in less than the 2 ft of cover, an ECM may have to
be recovered and stabilized.  ECMs could also become covered with
undesirable vegetation (thistle, weeds, etc.) that does not
retard soil erosion.
     Another important part of vegetation management is
maintaining vegetation at a height and density that will neither
obscure the ventilation indicator flag nor restrict foot access
to the top of an ECM for periodic soil depth checks.  Ideally the
vegetation on an ECM would be low-growing, require little or no
maintenance, retard soil erosion, not be a fire hazard, resist
invasion by woody and weedy herbaceous species and not be
desirable to livestock where grazing is permitted.
     Clearly, managing the vegetative cover on ECMs is extremely
important and must meet many requirements.  The purpose of these
guidelines is to assist land managers (App. A) in establishing
and maintaining ECM vegetation in a safe, efficient and cost-
effective manner.  This report attempts to address unique
management techniques that are not normally found in more general
land management guidelines.  Recommendations presented in these
guidelines or developed for a particular site with reference to
the guidelines should be incorporated into the Natural Resources
Management Plan and Installation Master Plan at each AMC
facility.
     The management procedures discussed in these guidelines are
intended primarily for conventional storage ECMs, not those used
for special weapons; however, many of the general procedures and
principles apply to both types of ECMs.  These guidelines focus
primarily on vegetation as the soil stabilizing element, but 40%
of the ECMs exist in dry areas where other material, in
combination with vegetation or alone, may be used to maintain the
soil coven Some of the methods used in these dry climates are
briefly discussed.


Ib.  Format of these guidelines
     These guidelines are structured so an AMC land manager can
obtain general information about the planning process for
managing vegetation, as well as specifics on vegetation
maintenance and establishment techniques.  Vegetation maintenance
is dealt with first because more time and money are spent
maintaining vegetation than establishing it.  The sections on the
specific maintenance techniques include uses, costs,
efficiencies, effectiveness, timing, safety and possible
environmental hazards associated with each technique.  Finally
the guidelines include numerous appendices that land managers can
use as they develop their vegetation management plans.  Appendix
B lists literature references used to obtain some of the
information presented here.  Literature citations are not
included in the guideline text to keep the text as easy to read
as possible.
     The guidance provided here is based on current knowledge and
ideas, which are continually changing.  Suggestions for changes
and additions should be mailed to: Commander, AMC Installations
and Services Activity, Attn.: AMXEN-M, Rock Island, IL 61299-
7190.


II. VEGETATION MANAGEMENT PLANNING

     A recent survey of AMC land managers has shown that it is
expensive to maintain ECMs.  Therefore, the land managers should
develop and implement a vegetation management plan to meet
established maintenance goals as economically as possible.
Appendix C shows the steps to follow in developing the plan.  To
be successful, the plan should be developed as early as possible
before vegetation operations to allow for review by Safety and
Security Offices so that all aspects of maintaining ECMs can be
considered.  Once these offices have approved the planning
document, the Quality Assurance Office should be told how the
maintenance operations will be conducted.  The plan should
consider the revegetation goals of all concerned offices, the
soils, the micro-climate, the type of vegetation best suited for
the site, the level of maintenance desired after construction is
completed and the cost and feasibility of revegetation
alternatives.  This section describes the general steps to be
taken by a land manager in evaluating and developing vegetation
management concepts and the plan (Fig. 2).


IIa.  Assessment of management goals
     Vegetation management goals must be determined and assigned
priorities at each AMC facility.  The goals, and the intensity of
treatments) to meet those goals, will depend on the projected
long-term needs and site characteristics of a facility, such as
climate, soil types, fertility, plant availability and costs.
Management goals usually achieved by establishing an acceptable
vegetation cover include maintaining ECM soil stability and
reducing maintenance costs.
     A vegetative cover should keep erosion at an acceptable
level, usually about one ton/acre annually.  Herbaceous species,
mainly grasses, are usually the dominant vegetation type.  Newer
varieties of standard species are continually being developed
that will meet established goals, and land managers should not
always rely on the "old standard mixture of species." Buying
"common" varieties or cultivars may lead to vegetation with
inappropriate growth habits and management problems.  Managers
should also inquire of upper management if more latitude in the
types of acceptable vegetative cover are possible, for example,
intentionally planting trees or allowing woody species to invade
ECM slopes and mowing a path to the ventilator flag for foot
traffic and line-of-sight observation.  New approaches could
reduce labor requirements and costs.
     Stabilizing the soil surface on ECMs is often the primary
goal.  Soil stability can be improved by reducing water or wind
erosion or minimizing freeze-thaw effects.  Herbaceous
vegetation, such as grasses and legumes, is usually selected to
provide soil stability because it is quick and economical to
establish and relatively easy to maintain.  Selecting appropriate
plant species mixtures and establishing management techniques
that require low maintenance will reduce labor and materials
costs.  These techniques may be different from those previously
followed, and the land manager should explain the changes and the
resulting benefits to the installation administrators.
     Vegetation establishment, however, may not be the sole
solution.  For example, on highly unstable slopes, engineered
slope controls such as terracing may be needed to ensure
stability.  Alternatives for dry areas include soil stabilizers
or aggregate covers with emulsifiers.
     At some point land managers must develop criteria by which
to evaluate whether their vegetation establishment and
maintenance goals have been met.  Success criteria may include
reaching a predetermined percentage of vegetation cover within a
given time or the reduction or elimination of particular weedy
species.  Evaluating success should be part of ECM management
plans.


IIb. Climatic zones and plant selection
     Climatic conditions are important for maintaining and
establishing vegetation and must be considered in developing
vegetation management plans.  AMC ECMs are located in four major
climatic areas:

  *  Dry (7 facilities, 40% of the ECMs);
  *  Dry-humid transition (7 facilities, 20%);
  *  Warm, humid (5 facilities, 14%); and
  *  Cool, humid (15 facilities, 26%).

The kinds of grasses and legumes recommended for seeding will
vary with geographical area because the adaptation of a species
to local climatic conditions is important to the likelihood of
its successful growth.
     The climatic factors that influence revegetation and growth
are:

  *  Amount and distribution of precipitation;
  *  Soil type;
  *  Air temperature patterns;
  *  Length of growing season;
  *  Wind;
  *  Humidity;
  *  Solar insolation;
  *  General seasonal variation;
  *  Micro-climatic variations on north- and south-facing slopes;
  *  Proximity and orientation to large bodies of water; and
  *  Altitude.

In the arid and semiarid west, extensive flat, minimally
vegetated areas contribute to strong, persistent winds, which
increase evapotranspiration.  Regional wind velocity and
direction can be obtained from the nearest weather station.
Climatic summaries for each state are available from the National
Weather Service.


IIc. Flammability
     Ten AMC facilities with ECMs are located in regions where
wildfires occur one or more times per year.  The chance that fire
will bum over an ECM is a function of the ignition source
(lightning or human), the weather and the type and quantity of
fuel on the ECM.  The steep slopes and elevation of ECMs promote
the drying of the vegetation by the wind and, therefore, the
spread of fire.  Fire-danger-rating systems predict the
intensity, rate and direction of fire spread, while fire-fuel
models compute the rate of spread, flame length and available
energy based on the structural, chemical and moisture
characteristics of the vegetation fuel.  In most models a major
distinction is made between fuel grass 0.5 and 1.5 ft high and
grass greater than 3 ft.  The importance of this consideration
increases at AMC facilities located in regions of the country
where wildfire is common, as in the and grasslands and shrublands
of the western U.S.
     Annual grasses like cheatgrass have high flammability
because they often die early and cure or dry quickly Perennial
grasses that are short, have a wide blade, maintain green foliage
and have a low proportion of standing dead leaves are less flam
mable.  A survey of four native grasses in Texas found that
buffalograss, was the least flammable; bluegrass (Poa sp.)
flammability is also low.
     Biomass (fuel loading), fuel moisture, compactness of fuel,
amount of finely divided fuels, fuel continuity, mineral content
in the vegetation, volatile compounds in the vegetation and
carbohydrates in the vegetation are the plant properties that
determine vegetation flammability and influence the intensity and
spread of fire.  Although plant chemistry is important in
evaluating vegetation flammability, the ratio of dead to live
vegetation and the distribution of litter on the ground is more
important.  Species that produce more biomass with fine leaves
and branches are most flammable; grasses are more flammable than
broadleaf forbs.  Clumped and sparse vegetation and plants with
high ash and moisture content and low calorie content tend to be
less flammable than more continuous vegetation with low ash and
moisture contents.
     Therefore, selection of species for revegetation of ECMs
should consider their fire-resistant or fire-retardant
characteristics: low dead-to-live ratios, low oil and resin
contents, coarse rather than fine leaves and stems, and succulent
(high moisture) rather than hard, dry foliage.  In general, most
cool-season grasses have lower dead-to-live tissue ratios more
months of the year than do warm-season grasses.  Reduction in the
amount of fuel and increases in the discontinuity of fuels are
probably the most important characteristics.  The access roads
within ECM areas serve as firebreaks.
     Although all burns that occur at AMC facilities are not set,
burning has been used as a cost-effective method of vegetation
control.  Grassland burning reduces weed seed numbers in the soil
and increases soil fertility and reduces biomass.  Although
controlled burning is a proven technique, it is not deemed
practical for vegetation control at this time.


IId.  Trees
     The planting of woody species on ECMs is a relatively new
idea in the United States, but it has been done in Europe since
World War II. On U.S. Army installations in Germany, trees are
grown on ECMs, with plans for harvesting them for poles and pulp
after 15-20 years.  Trees are also planted between ECMs to
provide shade for ECM slopes, which reduces drying of the slopes.
Various tree-harvesting scenarios may be developed depending on
the tree size, market factors and types of trees planted.
     A major benefit in growing trees is the reduction of annual
maintenance costs when the trees are actively growing.  The
primary savings will result from not mowing the ECM slopes.
Several drawbacks may exist.  One is the increased costs and
labor involved in planting the trees and the initial care, which
will probably last for two or three years.  Another potential
drawback is the growth of the roots around an ECK with possible
damage to it.  No problems in this regard have been noted in
Germany, although definitive studies to document the effects of
tree roots on the internal structure of ECMs have not been done.
Another drawback is the need to remove fallen limbs and leaves to
reduce fire potential.  Grazing lands, and the resulting income,
may also be lost, although trees could be planted only on the
slopes of the ECK leaving grass between them.
     The effect of a tree upon an ECM's Lightning Protection
System (LPS) is not known.  If the tree were to grow taller than
the LPS, it may attract lightning away from the LPS.  Current
regulation requires the LPS to be taller than surrounding
objects.  The tree's root system may offer an alternative path
for the lightning stroke to enter the magazine and bypass the
LPS.
     Although questions remain regarding the advisability of
growing trees on ECMs, they should be considered because of their
low maintenance costs.  This concept is being tested at Bluegrass
Army Ammunition Depot.  Updates will be provided as they are made
available by the U.S. Army Materiel Command Installations and
Services Activity.


IIe. Soil monitoring
     Characterizing on-site soils is important in developing a
site management plan for either vegetation maintenance or
establishment because the soil type directly influences a plant's
growth potential.  Soil type is based on physical, chemical and
biological properties of the soils.  Because ECMs are man-made
structures, the soils covering them are likely to be different
from the surrounding soils described on sod surveys.
Consequently it would be necessary to sample soils from several
ECMs to determine their properties.
     The growth potential of a site is its ability to maximize
initial plant growth until soil stability and related conditions
are met.  The growth potential of a site can be assessed in two
ways.  Site characteristics can be visually rated by trained
personnel at low costs based on the level of knowledge needed.
If more thorough knowledge is needed, the site characterization
may involve more elaborate quantitative procedures that require
more labor and money.
     The growth potential of a site can be visually assessed
according to its ability to provide adequate moisture and
nutrients and a favorable micro-climate for plant growth.
Adequate moisture will be determined by the amount of fine-
grained particles in the soil (Fig. 3), the amount of soil
organic matter and the climate.  In general, coarser-grained
soils hold less water for plant growth but also provide greater
aeration for better root growth.  Organic materials in soils
improve plant growing conditions by improving moisture- and
nutrient-holding capacities and soil structure.  Optimum soils
for plant growth potential are midway between coarse and fine
texture and between organic and mineral.
     Soil and climatic conditions where nutrient deficiencies are
likely to occur are shown in Table 3. However, routine soil tests
to determine the soil pH and the status and availability of the
more important nutrients must be done to determine site
fertility.  Local state university extension services will
usually do these tests at minimal costs.  They will also advise
on soil sampling techniques, such as appropriate depth,
composting and sample size.  The soil samples collected for these
tests should be taken from representative areas as determined by
variability in soil type, size of the site and allowable cost.
     Soil pH is important because of its direct effect on plant
growth and its indirect effects on plant nutrient availability
and elemental toxicity in soils.  Soil pH is usually measured to
test the need for lime, although a buffer pH measurement is also
needed to determine the quantity of soil acidity to be
neutralized to change the soil pH.  If soil acidity is below 5.5
or above 8.0, it should be modified; the most widely used
materials to raise and lower soil pH are limestone (Table 4) and
sulfur, respectively.  Soil pH ranges for optimum availability of
nutrients for the growth of several grasses are shown in Table 5.
In general the optimum pH range is 5.5-7.5.
     When removal of the earth cover for restoration or repairs
is planned, the land manager must specify to the construction
planners how much of the construction spoil should be stockpiled
for revegetation use.  The amount and type of topsoil and the
type of subsoil should be determined before or during the initial
disturbance.  Soil samples from borehole data can be used to
obtain this information prior to clearing an ECM.  The amount of
topsoil can be critical in successfully revegetating disturbed
areas.  Topsoil depths from 4 to 30 in. can be stockpiled in an
accessible area and reapplied prior to seeding.  If topsoil is
not available, it still may be worthwhile to place a fine-grained
subsoil (silt) over a coarse-grained (gravel) surface.  In
situations where there is only a thin veneer of topsoil or
organics (less than 4 in.), it is usually neither feasible nor
economical to segregate it.  Seeding directly on coarse-grained
soils, such as gravels, will require special soil amendments and
techniques, such as those discussed in Section IIel.  Properly
treated sewage sludge, composted sewage sludge, corn-posted
leaves, composted yard waste, manures or other proven sources of
organic matter are valuable assets to vegetation establishment,
particularly under difficult circumstances involving lack of
moisture and nutrients.


IIe1. Plant nutrients
     At least 17 plant elements are necessary for plant growth
and for improving plant health and survivability.  Carbon,
hydrogen and oxygen are obtained from carbon dioxide and water,
and nitrogen, phosphorus, sulfur, potassium, calcium, magnesium,
iron, manganese, zinc, copper, molybdenum, boron, chlorine and
nickel are obtained from the soil.  Symptoms of nutrient
deficiencies in plants are shown in Table 6, and methods for
correcting of nutrient deficiencies are shown in Table 7.
     Once a low-maintenance vegetative stand is established,
nutrients are recycled within the plant-soil ecosystem.  Nutrient
recycling may be enhanced through the use of legumes, the
addition of organic matter and the application of fertilizer.
Fertilizers can differ in their rate of release of nutrients into
the soil.  In general, chemical fertilizers are less expensive
and release their nutrients more rapidly than specially
formulated slow-release fertilizers.  Slow-release fertilizers
may have to be used at higher rates and will release nutrients
over a greater part of the growing season.  They may be necessary
on coarse substrates, such as sands and gravels, where the
nitrogen portion of normal chemical fertilizers is rapidly
leached away.
     Fertilizer selection should be based on plant types.  For
example, grasses require higher application rates of nitrogen
than do legumes.  In contrast, legumes and other nitrogen-fixing
plants require only small amounts of nitrogen but need large
amounts of phosphorus and potassium for establishment.
Excessively high rates of fertilizer not only increase costs, but
they can retard the growth of some slow-growing native species.
In general, fertilizer rates should be as low as possible while
ensuring adequate plant growth for erosion control or other site-
specific goals.  Composted materials (sewage sludge, leaves or
other organic materials) are sometimes considered economical slow-
release fertilizers.  Besides adding nutrients, organic materials
improve the structure of marginal soils.  Such materials are
usually tilled into the soil but are also helpful when spread
over newly sown areas, where they serve as a moisture-conserving
mulch and deterrent to soil crusting.
     Local environmental laws should be reviewed to determine if
permits are required to apply the organic materials.  AMC
recommends that land for application of organic materials be
reserved for "Army only" application.  Applying organic wastes
from neighboring municipalities is not recommended because it
utilizes land that may eventually be needed for Army waste
management.


IIe2.  Texture
     Soil texture is a measure of the proportions of sand, silt
and clay.  Sand, when dominant, forms a coarse-textured, or
fight, soil that allows water to infiltrate rapidly Silts and
clays make up fine-textured, or heavy, soils, and depending upon
the clay mineralogy they can be quite cohesive and slow to erode.
Soils that are high in silt and fine sand and low in clay and
organic matter are generally the most erodible.  Appendix D
describes the equations for estimating soil loss due to sheet,
rill and wind erosion.  General soils descriptions should be
developed for ECMs through soil surveys that include soil
particle-size groups as determined by a mechanical analysis using
standard sieves or by the hydrometer method or both.  A soil's
textural name is then determined by inserting the resulting sieve
data of each group in a textural triangle (Fig. 4, Table 8).


IIe3.  Physical measures to control erosion
     Historically, physical measures have not been used during
the construction of ECMs, even though past requirements called
for a minimum slope of 1 on 1.5 (rise on run).  Present
regulations call for a minimum slope of 1 on 2, which will still
require more maintenance than gentler slopes (Fig. 5). A better
scenario would have slopes constructed at 1 on 3. This would
increase revegetation. success and reduce management costs.  If
physical measures are required, water bars (to slow the flow of
water) and contouring (to direct drainage) should be considered,
with swales constructed below the slope to collect and remove all
drainage water.  Such swales should be well vegetated to prevent
erosion along the toe of the ECM slopes.


III.  MAINTENANCE OF EXISTING VEGETATION ON ECMs

IIIa.  Vegetation maintenance goals
     The land manager should strive for a management plan that
leads to minimum maintenance of the existing vegetative cover.
The ideal situation Would be vegetation that requires no
maintenance, but this is rarely possible because unattended
vegetation will change in composition and then may no longer
serve its intended purpose.  If this is allowed to continue, the
site usually degrades, water and wind erosion becomes a problem,
and very expensive, remedial revegetation practices may be
required.  Therefore, ECMs should be routinely monitored to
detect and correct problems that may lead to such conditions.
     Most ECMs require periodic maintenance to sustain an
adequate protective cover, and the schedule and kind of
maintenance should be part of any management plan.  For example,
fertilization may be needed to improve a vegetative stand, and
herbicides may be required to control tall vegetation around
ventilators.  However, the use of herbicides and brush-cutting
equipment can be minimized by using selective herbicides, by
cutting woody vegetation only at certain times of the year and by
encouraging the establishment and growth of acceptable, low-
growing herbs and grasses around ventilators to minimize invasion
by other species.


IIIb.  Site assessment
     Land managers must familiarize themselves with local
conditions that affect their site by doing site evaluations with
regional or local technical experts, noting those site
characteristics and situations that may prevent appropriate plant
growth.  They will need enough resources and funding to avoid
expensive consequences.  Situations managers must watch for
include:

  *  ECMs with south- and southwest-facing slopes that are hard
      to vegetate;
  *  Very poor or highly erodible soils on ECM slopes;
  *  Invasions by weeds that prevent the growth of desirable
      vegetation;
  *  Slopes that are too steep; and
  *  Overgrazing.

Land managers must determine the priority of problems by
considering the potential effect on a facility's mission if left
uncorrected.


IIIc.  Specific maintenance practices
     Sections IIIcl-9 describe some of the advantages and
disadvantages of each technique and will aid AMC land managers in
preparing a vegetation management plan.  The goal of all the
techniques is to maintain a low-cost protective cover on ECMs
that meets the needs of a particular facility.
     All maintenance operations should be planned for the season
when the benefits will be greatest or the costs will be least.
For example, if mowing is required, it could be done near the end
of a rapid plant growth time instead of every two weeks or
monthly throughout the year.


IIIcl.  Practice:  No vegetation maintenance
 a. Possible uses:
  *  Alternate periods of no maintenance with periods when
      other maintenance techniques are used to reduce overall
      long-term costs.
  *  Allows a vegetative cover to change composition and to
      decrease its areal extent in anticipation of starting a new
      vegetation stand.
  *  In dry areas, allows vegetation cover to occupy sites where
      aggregate has been applied.

 b. Relative expense:
  *  Low initial cost.
  *  Can lead to expensive remedial work, either to rebuild an
      eroded ECM slope or to reestablish acceptable vegetation on
      a slope left unmaintained for too long.

 c. Efficiency of human resource use:
  *  High because few resources are used when no maintenance is
      required.

 d. Relative effectiveness:
  *  Could lead to soil instability due to thinning turf and
      deteriorating and changing plant cover, with subsequent
      water and wind erosion depending on site conditions and
      climate.

 e. Optimum timing:
  *  None.

 f. Safety risk:
  *  Low because few activities are required.

 g. Environmental hazards:
  *  None.


IIIc2.  Practice: Mowing

 a. Possible uses:
  *  Reduces fire hazard.
  *  Lowers plant height to allow viewing of and access to vent
     and ventilator flag.
  *  Reduces woody plant growth.

 b. Relative expense:
  *  High because mowing equipment must be maintained and fueled.

 c. Efficiency of human resource use:
  *  Low because mowing is time-consuming.
  *  Could restrict mowing to only around ventilators.
  *  Mowing is not recommended in AMC-R 385-100.

 d. Relative effectiveness:
  *  Moderate to low overall.
  *  Immediate effectiveness is high but short-lived where
      vegetation grows fast.
  *  Mowing may damage shaped slopes
  *  More than 50% of the AMC facilities (with 72% of the ECMs)
      don't mow ECMs.

 e. Optimum timing:
  *  Mow grasses near end of periods of rapid growth.
  *  Mow wildflowers in the fall.
  *  Some legumes do not need mowing.

 f. Safety risk:
  *  Moderate to high due to hazards inherent in mowing a slope.
  *  Mowing gets more hazardous as the slope steepens.

 g. Environmental hazards:
  *  Uses small amounts of fossil fuels and has only a slight
      impact on air quality.
  *  Mower wheels sear steep banks, inviting weed invasion and
      erosion.


IIIc3.  Practice: Application of fertilizers and lime/sulfur
 a. Possible uses:
  *  Can aid in establishing new seedings.
  *  Reduces weed invasion and improve stand of desirable
      vegetation.

 b. Relative expense:
  *  Moderate depending on existing vegetative cover.
  *  Application rates of chemical fertilizers depend on climate;
      in the east, rates are usually about 40-80 lb/acre of
      nitrogen and about 40 lb/ acre of phosphorus and potassium
      per year; in colder climates, rates of up to 60 lb/acre of
      phosphorus and potassium are frequently required.

 c. Efficiency of human resource use:
  *  Moderate to high because after initial fertilization and
      liming, plants will grow better and require less
      maintenance except for mowing.
  *  Important to accurately determine the amount of fertilizer
      and lime required to minimize labor (soil tests).

 d. Relative effectiveness:
  *  High because a vegetative stand may fail without proper
      nutrients.

 e. Optimum timing:

  *  In humid areas, fertilizer should be applied in the fall to
      limit topgrowth.

 f. Safety risk:
  *  Low.

 g. Environmental hazards:
  *  Low.


IIIc4.  Practice: Application of herbicides
 a. Possible uses:
  *  Rids ECM slopes of undesirable plants that allow soil
      erosion, adversely affect grazing, obscure ventilator flags
      or restrict access to an ECM ridge; consult TM 5-630 and
      local university extension services for herbicides since
      such recommendations are subject to change.
 b. Relative expense:
  *  Moderate to high.

 c. Efficiency of human resource use:
  *  High because once a herbicide is applied, unwanted
      vegetation will be eliminated for at least one growing
      season and probably three or more.
  *  Must be applied by trained and certified personnel
      (AR 420-76).

 d. Relative effectiveness:
  *  High.

 e. Optimum timing:
  *  Extremely important; varies with vegetation, climate and
      herbicide.

 f. Safety risk:
  *  Moderate but potentially high if safety precautions are not
      followed.
  *  Labels contain detailed precautions.
  *  Worker exposure.

 g. Environmental hazards:
  *  Can impact endangered and other non-target species,
      contaminate water supplies and become wind-borne during
      application, possibly impacting or contaminating distant
      locations.
  *  Can kill legumes.


IIIc5.  Practice: Application of plant growth regulators (PGRs)
 a. Possible uses:
  *  Suppresses vegetation on EMCs and other difficult-to-mow
      areas.
  *  Suppresses grass seedhead formation.
  *  Reduces mowing frequency and maintenance costs.

 b. Relative expense:
  *  Cost-effective if applied correctly
  *  Savings depend on cost of chemical and its application vs
      current cost of mowing.

 c. Efficiency of human resource use:
  *  High because of reduced mowing.

 d. Relative effectiveness:
  *  High; manufacturer's label recommendations must be followed
      to obtain desired results.
  *  PGRs are compatible with most turfgrass herbicides.
  *  Should not be considered a replacement for mowing but rather
      as a method to reduce mowing frequency
  *  Small test plots should be established on site to determine
      PGR effectiveness prior to general use.
  *  Certain chemicals may not regulate growth throughout the
      year.

 e. Optimum timing:
  *  Timing of application is critical and dictates treatment
      success.
  *  Timing of PGR applications varies with grass species and
      location.
  *  Follow label recommendations for optimum effectiveness.
  *  Most PGRs should be applied in spring when grasses are
      rapidly growing and before seedheads emerge.

 f. Safety risks:
  *  Follow safety recommendations on manufacturer's label.
  *  Use licensed applicators.
  *  Use proper application equipment.

 g. Environmental hazards:
  *  Possible effects to non-target vegetation; read product
      label for list of susceptible plant species.
  *  Follow restrictions listed on product label.
  *  Monitor treatment application and results.


IIIc6   Practice: Overseeding
 a. Possible uses:
  *  Improves a sparse vegetative cover.
  *  Establishes. new cover primarily for reduced maintenance.

 b. Relative expense.
  *  Low to moderate.

 c. Efficiency of human resource use:
  *  High.

 d. Relative effectiveness:
  *  Sometimes unsuccessful because of inadequate seed-soil
      contact resulting from broadcast seeding operations (ECM
      slopes are usually too steep for conventional no-till
      seeding equipment).
  *  Some success has been achieved with fine fescues (chewings,
      hard, sheep and red) in the transition zone of the United
      States.
  *  Long lasting if successful.

 e. Optimum timing:
  *  Seeding on frozen soils in the spring and allowing the
      natural freeze-thaw action to improve seed-soil contacts
      (frost seeding) has the best chance of success in all but
      the warmest climates in humid areas.

 f. Safety risks:
  *  No safety hazards unless tractor-drawn equipment is used on
      steep slopes.
 g. Environmental hazards:
  *  None.


IIIc7.  Practice: Grazing
 a. Possible uses:
  *  Produces income that can be used to improve or maintain AMC
      lands, (about 30% of AMC magazines are grazed).
  *  Helps keep vegetation under control.

 b. Relative expense:
  *  Low.

 c. Efficiency of human resource use:
  *  High because little labor is required.

 d. Relative effectiveness:
  *  Often promotes weed invasion.
  *  Can promote erosion.
  *  Causes soil compaction, which retards plant growth,
      resulting in more down-slope water flow and soil erosion.
  *  Proper grazing management largely eliminates the above.

 e. Optimum timing:
  *  A plan should be implemented so the lands are fully utilized
      but not overgrazed.

 f. Safety risks:
  *  Low.

 g. Environmental hazards:
  *  Low.


IIIc8.  Practice: Soil stabilizers (emulsions, asphalt cut-back,
         latex, etc.)
 a. Possible uses:
  *  Temporary soil erosion control.
  *  Dust abatement.
  *  Sand stabilization.
  *  Tackifier for holding mulch and seed in place.

 b. Relative expense:
  *  Medium to high.
  *  Application rates for each product depend on intended use,
      climate and degree of problem.
  *  Not an economical alternative where vegetation can be easily
      established.
  *  Often the most economical alternative where vegetation is
      difficult to establish.

 c. Efficiency of human resource use:
  *  High because spray applications can cover large areas in
      little time.

 d. Relative effectiveness:
  *  High if applied correctly.
  *  Depending on climate and disturbance, soil stabilizers may
      retain effectiveness for two years or more.

 e. Optimum timing:
  *  Any time when soil is dry enough to support wheeled vehicles
      and temperatures are above freezing.

 f. Safety risks:
  *  Most commercial products are latex-acrylic copolymers that
      are non-corrosive, non-toxic and non-flammable.
  *  Some products may cause skin, eye and respiratory
      irritation; protective clothing may be required.

 g. Environmental hazards:
  *  Most commercial products may be sprayed on existing
      vegetation without harm.
  *  High concentrations of some products may harm aquatic
      organisms.


IIIc9.  Practice: Forestation*
 a. Possible uses:
  *  Reduction in weed growth and mowing operations.

 b. Relative expense:
  *  High initially, but low over a 10-year period.
  *  Return on investment is decades long.

 c. Efficiency of human resource use:
  *  High.

 d. Relative effectiveness:
  *  Probably high but not much data available.

  *  Concerns for root penetration of cracked concrete.
  *  Concerns for lightning protection.

 e. Optimum timing:
  *  Extremely important.
  *  Consult state forestry agency.

 f. Safety risks:
  *  Low for hand planting; machine planting not recommended on
      steep slopes.

 g. Environmental hazards:
  *  None.

------------------------------
* Forestation is not recommended at this time except on
an experimental basis.
------------------------------


IIId.   Cost-benefit analysis of different techniques
     It is important that early in the planning phase the land
manager develop cost estimates for materials, labor, equipment
and maintenance involved in each treatment being considered to
assess how each fits into monetary constraints.  When estimating
overall treatment costs, prices for plant and other materials,
including soil amendments and labor and equipment time for each
operation within a given treatment, must be determined.
Maintenance costs for the various treatments would include site
monitoring, refertilization, herbicides, plant growth regulators,
pesticides, mowing or brushing, and watering.  Comparisons for
each maintenance technique described in this section are
summarized in Table 9.
     Values used for the materials and labor costs can be chosen
from local averages or from the national averages listed in
Building Construction Cost Data (see Robert Snow Means Co., Inc.,
1978, App.  B), a reference to aid contractors in anticipating
their construction expenses.  Calculating a treatment
installation cost basically involves adding all expenses.



IIIe.   Evaluating success
     After maintenance operations are completed, their success
should be evaluated.  Sample questions to ask are: Is the
vegetative stand thicker after fertilizations What percentage of
the weeds were controlled by herbicides?  Any maintenance
operation should result in a vegetative cover of more than 50% of
the soil surface.  The cover species to consider are desirable
perennial plants and not annual weeds.


IV. ESTABLISHMENT OF VEGETATION ON ECMs

IVa.    Goal assessment
     The goals will likely be the same as for maintaining
existing vegetation (see Section IIIa).


IVb.    Site assessment
     The amount of revegetation effort required at the end of
construction can be greatly reduced through proper planning (Fig.
6).  Previously disturbed and revegetated ECMs should be
monitored to determine successes and failures of the revegetation
techniques; this should be done by visiting the site, talking to
the people who were in charge of the site restoration, and
studying the construction and revegetation plans.  The land
manager should have input into the seasonal timing, species
selection, renovation or construction work.  This will require an
extra effort in the planning stages before any contract is
finalized.
     Once goals for revegetation are set, but before ECM
renovation begins, the land manager must make visual assessments
and soil fertility and physical tests to anticipate likely after-
construction conditions and to verify the site's stability, its
ability to support new plant growth and the likelihood of
reinvasion by undesirable vegetation.  It is not unusual for soil
and climatic conditions to vary on individual facilities, making
it necessary to assess ECM areas separately and develop separate
revegelation plans for each area.  Also, the orientation of EMCs
affects vegetation performance and persistence.  Southwest-facing
slopes are the hottest and driest and therefore most difficult to
maintain adequately.
     After the revegetation goals have been established and a
site's stability and ability to support growth have been
assessed, the next step is to identify the specific treatments
that will meet the revegetation goals most effectively This
identification process will be in two steps: plant selection and
site preparation and seeding.


IVc.    Plant selection
     Planning new seedings after construction provides an
excellent opportunity to introduce low-maintenance plants that
will satisfy goals.  Consideration should be given to newer
varieties of the standard species and species that are unique to
AMC installations.  The larger seed companies can work with land
managers to help select or demonstrate beneficial species.  Some
examples of new low-growing varieties that have potential for low-
maintenance slopes are Appalow lespedeza and the more drought-
resistant varieties of the hard, red, chewings and sheep fescues.
Before planting any species, inquire about its tolerance to the
soils and climatic conditions existing at the site, as discussed
in Sections IIb and e.
     As with any organism, plants grow in close interaction with
their immediate environment.  Temperature-dependent variables of
the environment that greatly affect plant survival, growth and
reproduction include evaporation, insolation (sunlight), soil-
forming processes, soil microbiota, plant nutrition, and animal
pollinator species and activity Factors influencing the amount
and composition of the vegetation on ECMs include grazing
history, soil nutrients, precipitation, slope exposures and
steepness, proximity to forest and time since resurfacing.  The
plants on ridges and south-facing and upper slopes of ECMs are
generally less dense than on north-facing slopes, probably due to
greater moisture and heat stresses.  Appendix E names herbaceous
species that may be selected for revegetation purposes.  Appendix
F provides seed mixture recommendations for individual
facilities.  This type of information is also available from
local university extension offices and the Soil Conservation
Service (App. G).
     Land managers may want to use native species in a
revegetation project.  This choice may be influenced by
vegetation management goals, site use and location, availability
of seeds or plants and relative costs.  Some of the advantages
and disadvantages of native and introduced species are shown in
Table 10.
     The quality of the planting material must be specified when
available.  It is preferable to use certified seeds that meet
USDA standards.  If these are unavailable, the manager should
specify the place of origin, and the producer should be contacted
to determine the seed's suitability for the site.  Labels should
list the minimum germination percentage and content of desirable
species, the percentage of purity and the maximum percentage of
weeds.  Seeding rates will be given in the amount or weight of
pure live seed (PLS) to apply per unit area (determined by
multiplying the seed purity percentage by the germination
percentage).


IVd.    Site preparation and seeding

IVd1.   Timing of establishment practices
     Some revegetation activities, such as procurement of
materials and the use of equipment time and labor, need to be
scheduled as far in advance as possible to allow maximum
flexibility, improve equipment utilization, and lessen the
likelihood of costly delays, particularly those that impose
seasonal constraints on revegetation.  Site-specific plans should
be written in advance so there will be adequate lead time to
procure materials.
     Planting should always take maximum advantage of the local
growing season.  The recommended planting or seeding times
maximize the chances that emerging seedlings and transplants will
encounter optimum temperatures and moisture and will survive
through the winter.  Optimum temperatures for seed germination
are shown in Table 11.  Both spring and fall may provide optimum
temperatures.  It is important, however, to know if the chosen
species is better adapted to either a spring or fall seeding.


IVd2.   Seeding considerations and techniques
     Many of the treatments discussed here require specialized
equipment.  A small crawler tractor, bulldozer or conventional
farm tractor is usually required.  Soil preparation equipment
depends on the site and tillage depth desired but could include a
chisel plow, a conventional plow or a disk to loosen the surface
soil and to mix amendments into the soil.  Fertilizers are
usually broadcast over the soil surface with a centrifugal or
gravity-flow spreader, drilled into the soil, broadcast with a
hydromulcher or applied aerially.  Soil amendments, such as
limestone, compost or manure, are also usually broadcast and then
harrowed into the soil.  Seeding is usually performed with a
drill or cultipacker on more level sites and with a hydroseeder
on steep slopes.  Transplanting usually requires hand labor.
Mulch may be spread by a hydromulcher, a blower or a manure
spreader.  It is important that operations, particularly in later
stages, be on the contour, since water retention is important and
erosion is a possibility.
     Unless there are special goals or characteristics of the
site, it is generally preferable to be as flexible as possible
regarding equipment.  Functional requirements such as "seedbeds
must be left uncompacted and roughened" and "seed and fertilizer
must be incorporated into the upper two inches of soil" must be
clearly stated in bid requests.  This allows the contractor to
choose the most cost-effective types of equipment to meet the
contract requirements.  Figure 6 and Appendix C should be used
while developing a seeding contract and guide.
     In cold climates a decision must then be made concerning the
seeding schedule, since timing may be crucial for the successful
establishment of grasses and legumes for controlling soil erosion
on ECMs.  Revegetating in the fall requires the scheduling of
seeding and mulching for either permanent or dormant seedings.
Permanent seedings must be early enough to permit seedling
establishment and avoid winterkill; dormant seedings must be late
enough in the fall to delay germination until spring.
     There is a one- to two-month period between the latest date
for permanent seeding and the earliest date for dormant seeding.
If seeding occurs between these dates, there is an increased risk
of seedling mortality due to low fall and winter temperatures.
Depending on the date of project completion and the site,
permanent or dormant seedings are more desirable than seeding
within the transition period.  Table 11 shows the optimum soil
temperatures for seed germination for various northern agronomic
grasses; this information is useful in selecting seeding dates,
particularly in conjunction with knowledge of cool vs. warm
season stress tolerance and frost-heaving potential.
     Temporary revegetation is used to stabilize slopes when
permanent measures cannot yet be established, due to an incorrect
seeding time or the failure of an ECM due to soil slippage.
Temporary seedings may require heavy fertilization and seeding.
Temporary physical stability measures, such as installation of
geofabrics, mulches and stabilizers and culverts, may be needed
after a site is disturbed and before permanent vegetation steps
begin, Short-term maintenance commences immediately after grading
or when planting is completed.  This may include protecting an
ECM from grazing by erecting temporary fences.  Close monitoring
to correct early failures and to ensure success is recommended.


IVd3.   Fertilizer and soil amendments
     After ECMs are renovated and re-covered with soil, growing
conditions can be improved to increase the rate of establishment
and growth of plants.  Applications of fertilizer before or
during seeding will provide needed plant nutrients such as
nitrogen, phosphorus and potassium.  The rate of fertilizer
applied will depend on the initial fertility of the soil and on
estimated natural organic and micronutrient sources, as indicated
by soil test results obtained some months before seeding.
Sources of nutrients are shown in Tables 12-14.  Commercially
available mixtures should be used whenever possible to reduce
costs.
     Organic soil amendments are usually considered for improving
fine- and coarse-textured soils.  These include composted sewage
sludge, native organics, manure or straw.  They will improve
plant growth in coarse soils by increasing soil water-holding
capacity and nutrient retention and in fine-textured soils by
increasing infiltration rates and improving soil aeration and
structure.


IVd4.   Mulches
     On newly seeded sloping soils, mulches are beneficial in
counteracting excessive or deficient moisture, as well as in
protecting against soil crusting.  Mulches retard soil erosion
and seedwashing during heavy precipitation and retain moisture
during dry periods.  A mulch is most effective during the first
growing season since its purpose is to promote seed germination
and seedling establishment by maintaining a more nearly optimum
soil temperature and moisture content and by reducing surface
soil movement.  These benefits are seldom effective after one
growing season.
     Many materials are used as mulches; hay or straw remain the
most economical and popular (Table 15).  The greatest drawback of
hay and straw is that they may introduce weed seeds onto the
site.  Some of the other popular mulches include wood-based
materials (excelsior, wood chips, shredded bark), fabric or mats
(jute, excelsior, woven paper), manure, sewage sludge and wood
cellulose fiber.  Most mulch materials require tacking to keep
them in place.  This may be a netting staked or stapled into the
ground, an adhesive agent sprayed over the mulch, or straw or hay
pressed into the soil surface by a "mulch coulter."


IVe.    Evaluating success
The warranty period for determining if a seeding operation was
successful is usually up to a year after seeding is completed.
The criteria for determining success can include a simple visual
observation or a count of the number of sown plants per unit area
(ft2).  Both methods require inspectors who can recognize the
types of plants sown when they are in the seedling stage.  Simple
visual observations are not recommended, however, since they are
too subjective and can be debated.
     Counting the number of plants per unit area is the most
accurate method since it is quantitative.  The number of pure
live seed (seed that will germinate) sown per unit area should be
determined, and a fraction of this number should be guaranteed by
the contractor (see Section IVd).  The actual number of plants to
meet the requirements of a successful seeding is determined by
the climatic area.  Drier climates should have a lower number of
plants per unit area.  The actual number used should be developed
with the assistance of a local county extension office.
     The counts should be made after a sufficient amount of time
has passed for a seed to germinate and become established.
Counts are made by randomly selecting a number of areas.  One
sampling about one square yard per 0.25 acres should be
sufficient.  If seedlings cannot be identified, they may be
brought into a greenhouse to increase their growth rate and
improve the identification.  Inspectors should also be aware of
the types of plants sown so they can determine if those plants
are present.
     Evaluating success is the last chance in the plant
establishment process to obtain an optimum plant cover.  Poor
plant stands that are not connected at this time will result in
more difficult and expensive plant management techniques.  Land
managers should work closely with inspectors to ensure that a
suitable plant cover is obtained.



                  ***Appendices & Worksheets***
                    ***Unavailable On-line***