Soil Survey Manual - Chapter Five
Information Recording and Management
Introduction
Information gathered during a soil survey of an area is recorded partly on
maps and partly as notes. The two methods of recording work together to ensure a
quality survey.
Field Notes
Field notes include both information on the behavior of the soils and
inferences about how the soils formed. Field notes make up the basic information
used in developing the descriptive legend, soil interpretations, and the
manuscript of individual soil surveys. The notes are used for preparing standard
definitions and descriptions of soil series and for correlating soils in the
national program. Field notes are as important as the field sheets on which
accomplishments are recorded.
The best notes are those written while observations are fresh. For example,
the description of a soil profile is recorded as it is examined. Information
from a conversation with a farmer is best recorded during the conversation or
immediately thereafter. Unless notes are recorded promptly, information may be
lost. All field notes should be clearly identified. The survey area, date,
location, and author are necessary on loose-leaf sheets and tape recordings. The
date and location are needed for each entry in a notebook. Each note should be
related to an identified soil. The source of information that is obtained other
than from direct observations should also be identified.
Field notes must be understandable to all survey personnel. Shorthand notes
need to be transcribed to be useful to others. Only common words and
expressions, as found in a standard dictionary, should be used.
The most important notes record the commonplace—extensive kinds of soils and
their properties, the common crops, the success of septic systems, and so on.
The tendency to record other than the commonplace should be avoided, because
subsequent efforts to prepare a descriptive legend or make interpretations from
such notes will be unsuccessful. Field notes should indicate how closely they
represent the commonplace. Survey personnel must first learn to see and record
the commonplace, then add departures from the usual.
Field notes record observations and complete descriptions of pedons at
specially selected sites. Notes that are made during mapping are usually not
full descriptions. They may record only color, texture, and thickness of major
horizons as seen in auger cores (fig. 5-1). The information is used to
supplement detailed examinations. Notes of this kind are especially important
for soils that are not well known and for soils of potential, but questionable,
map units.
Field notes include information about the relationship of map units to one
another, to landforms, and to other natural features. The setting of a soil—its
position in the landscape—is important. Landscape features strongly influence
the distribution of soils. From the landscape, the properties and extent of the
soil and the location of soil boundaries can be deduced. The kind of landform or
the part of it that a particular soil occupies and how the soil fits into the
landscape should be described. Soil patterns and shapes of soil delineations are
important in relation to large-scale soil management. Landscape identification
is discussed in chapters 2 and
3 of this manual.
The kinds and amounts of inclusions in map units, as well as their positions
in the landscape, are noted and recorded during fieldwork. The inclusions are
either identified by name, or their contrasting properties are described.
Although the kinds and amounts of inclusions vary from delineation to
delineation, an experienced surveyor has little difficulty in maintaining an
acceptable level of interpretative purity within a mapping unit. This is due to
the fact that most contrasting inclusions (dissimilar soils and miscellaneous
areas) occupy specific, easily recognized positions in the landscape. If a
precise estimate of the taxonomic purity of a given delineation is needed,
special sampling techniques—line-transects or point-intercept methods—are
required (ch. 2).
Notes should be made on soil erosion in particular map units. This could
include such items as descriptions of eroded areas, degrees of erosion within
and between phases, differences in variability among soils and landscape
positions, extent of redeposition in map units, and effect of erosion on crop
yields and management of the soil (ch. 3).
Soil behavior concerns the performance of a soil as it relates to
agricultural productivity, its susceptibility to erosion, and its performance as
a foundation for houses or as a waste-disposal site. Notes on soil behavior,
unlike those on nature and properties, are obtained largely from the
observations of others. In addition, field scientists record direct observations
and make inferences which should be labeled as such.
Notes on behavior focus on the current and foreseeable uses of the important
soils in an area. Where range is the primary use of a survey area, information
on range production may be needed for all of the soils of the area. Notes on the
performance of soils under irrigation, however, would probably be needed as well
where the soils are irrigated. Information on probable forest growth might be
pertinent to the purposes of the survey even though it comes from the experience
of only a few individuals or a few kinds of soils. An area of rapidly expanding
population needs data on the engineering performance of soils—how well the
different kinds of soils would support houses, what kinds of subgrades are
required for streets and roads, and whether onsite waste disposal systems would
function satisfactorily.
Valuable information about soils can be obtained from observations made in
the field while surveying. Soil scientists can see poor crop growth on a wet
soil or on an eroded area. They note the failure of a road subgrade or of an
onsite waste-disposal system in specific kinds of soil. On the other hand, data
on yields and management practices for specific crops usually come from farm
records or experimental fields. Similarly, information on forest growth is
usually derived from observations made by others, but can be supplemented by
information recorded by the soil scientist. Most information on the engineering
performance of a soil comes from people who work with structures and soil as a
construction material. During field work, a special effort should be made to
obtain this kind of information from knowledgeable people.
The source of information about soil behavior is evaluated and recorded in
the field notes. Inferences are to be clearly distinguished from observations of
soil morphology, vegetation, landform, and the like. Most notes about how soils
formed, for example, are inferences. The condition of growing crops is
observable, but statements about soil productivity based on such observations
are inferences. That soil material is nearly uniform silt loam and lacks coarse
fragments is directly observed; the conclusion that the soil formed from loess
is an inference.
Theories that have been formed on the basis of inference should not unduly
influence the choice of observation sites or the properties to be observed.
Form and Storage of Notes
Each field party should devise a simple, easy system for taking and filing
field notes. No single way of taking field notes is prescribed, because no
standard system necessarily works well in all parts of the country.
Most field notes are handwritten, in longhand or shorthand, and are
immediately available for reference. Such notes can be typed later, although
typing is seldom necessary if the notes are neat and well-organized.
Portable tape recorders and small computers can be used for taking field
notes. Note taking will need to be well organized for this method. The risk of
oversight is larger with tape recordings than with handwritten notes because
less time is available for reflection when recording the spoken word than when
writing notes. Tapes should be played back after notes are recorded. Recorded
notes are usually retrieved and typed later for filing.
Photographs are a quick and accurate way to store information. They could be
used more often in soil surveys than they have been in the past.
The sizes and formats of the notebooks that are used in soil surveys depend
on working conditions and personal preferences. Large notebooks with pages of
about 21 x 27 cm provide ample space for writing and sketching. Smaller
notebooks, 8 to 13 cm in width and 13 to 20 cm in length, have advantages for a
person on foot because they can be carried in a pocket. Loose-leaf notebooks,
springback binders, and clipboards are widely used. These permit easy sorting
and arrangement, if notes for only one site or observation are made on a sheet.
Completed sheets can be filed at field headquarters every day. For the study of
large areas and for reconnaissance trips, small bound notebooks are less bulky
and less apt to be misplaced than are the individual sheets. Computers also can
be used to store information.
The filing system set up at field headquarters to preserve the information
should be as simple as possible and yet allow recovery of the information when
it is needed. All withdrawals from the files should be recorded.
In early stages of a survey, a standard filing cabinet with a folder for each
map unit is sufficient. Alternatively, descriptions and notes can be kept in
binders arranged by map units and taxonomic units. Map unit descriptions and
notes are usually filed under series name plus modifiers. A separate folder is
provided for notes that apply to the series as a whole. The mechanics are not
important as long as notes and descriptions are accessible.
As a survey continues, additional folders are usually needed for soil
interpretations, for the various kinds of general information about the area,
for photographs, and for miscellaneous notes. Separate folders generally are
kept for the specific sections in the soil survey manuscript—geology,
vegetation, land use, crop yields, soil suitability, soil potential ratings, and
others. As the survey progresses, having the information and notes on each topic
in one place becomes increasingly useful, and the notes are transferred to
individual files.
Cross-referencing helps in finding notes that include information on more
than one subject. For example, a given note may contain both information on the
nature of a map unit and on the yields of one or more crops. That note can be
placed in the folder for the map unit and a reference to the map unit placed in
the file on crop yields.
Much of the information in field notes is summarized in the descriptive
legend. Field notes on soil behavior are repeated or summarized in sections of
the soil handbook. Although the information in the soil handbook and descriptive
legend is readily accessible, not all of the field notes are included.
Consequently, the original notes are kept on file.
Field notes and information in the soil handbook and descriptive legend are
very useful after publication for evaluation of the soil survey. Adequate notes
help soil correlation and interpretation specialists to update an old survey and
eliminate the need to completely remap the survey area. This information can be
copied and stored in the computer, on microfilm, or on microfiche. Computer
disks and microfiche copies are inexpensive and may be very useful to technical
staffs. The original paper can then be discarded.
Soil Profile Descriptions
Soil profile descriptions are basic data in all soil surveys. They provide a
major part of the information required for correlation and classification of the
soils of an area. They are essential for interpreting soils and for coordinating
interpretations across State and regional boundaries. The soil descriptions and
the soil map are the parts of a published survey having the longest useful life.
Field descriptions of soil profiles range from partial descriptions of
material removed by a spade or by an auger to complete descriptions of pedons
seen in three dimensions from intersecting pits as horizontal layers are removed
sequentially from the surface downward. Most field descriptions of soil profiles
are the former, so care in making them is essential.
Field descriptions should include:
- Observed external attributes of the polypedon, such as landform and
characteristics of slope;
- Inferred attributes of the polypedon, such as origin of soil parent
material and the annual sequence of soil-water states;
- Observed internal properties of the pedon, such as horizon thickness,
color, texture, structure, and consistence;
- Inferred genetic attributes of the pedon, such as horizon designations and
parent material;
- Inferred soil drainage class;
- The classification of the pedon in the lowest feasible category;
- The location of the site relative to geographic markers and in terms of
landscape position;
- The plant cover or use of the site;
- The date, time of day, and weather conditions; and
- The name of the describer.
The degree of detail that is recorded depends on whether the description is
intended to provide a complete standard for comparing the other pedons placed in
the same taxonomic class or simply to determine the variation of a selected
property within a taxon.
The attributes of pedons and polypedons, procedures for describing their
internal properties, and standard terminology are described in
chapter 3. When
standard terms are not adequate to characterize all properties and attributes of
a soil, common descriptive words are used to elaborate.
Standard Forms for Soil Profile Descriptions
Standard forms are useful for recording the observations and data required in
a soil survey. They permit recording of information in a small space. Examples
of standard forms used for soil profile descriptions, along with some additional
information, are illustrated in figures 5-2 and
5-3. These figures are merely
examples, because no standard form covers all situations. Furthermore, forms
require modification as more is learned about soils and how to evaluate data.
Standard pages or forms can be prepared in different sizes to fit various
notebooks. Forms printed on blue rather than white paper produce less glare when
used outdoors.
Handheld computers can be programmed, following a standard format, to permit
entering soils information while in the field. The information can be downloaded
later to a computer in the office. The office computer can be used for storage
of information, sorting, and printing out the description.
A standard form serves as a checklist of characteristics that should be
recorded. A checklist is especially valuable for beginners because it reminds
them to look for at least the listed properties, but observations should not
stop with the listed properties. There is a strong tendency to record the
information required by the form and then stop. Thus, a form designed to set a
minimum on the amount of information recorded also tends to set a maximum. Good
soil profile descriptions, however, require information beyond that needed to
complete the form.
Standard forms are most useful for recording the day-to-day observations made
during mapping. Many such notes are not full descriptions of pedons. These short
notes can usually be made on a standard form more easily than they can be
written in longhand. Abbreviated notes are also useful in recording many
observations during field reviews and when transecting. For these and similar
purposes, the forms make note-taking easier and lessen the risk of recording an
inadequate description. Complete descriptions of pedons, such as those made when
soils are sampled for special studies or those of the typical pedons of soil
series, can be written in longhand as block descriptions on a standard form
which becomes a checklist.
Notations on forms.—The small spaces on standard forms require that
abbreviations or symbols be used for much of the information. Words can be used
to identify and describe the polypedon; symbols are needed for internal
properties. Many different standard notations have been used. The symbols and
codes used by each soil scientist should be documented either (1) by defining
the individual’s own notations or (2) by referencing a standard document, such
as chapter 3 of this manual or the pedon coding system used by the National
Cooperative Soil Survey. Individual documentation should become a permanent
record of a survey area so that the information can be correctly interpreted by
others.
The most serious error in using standard symbols is using a symbol when it is
not fully appropriate. Additional notes are needed to supplement symbols that do
not convey the facts completely and accurately. Another error is the
introduction of individual variations in use of the standard symbols. This
complicates use of descriptions by others and can defeat the purpose of standard
terminology. Standard notations are used exactly as defined.
Field descriptions in which abbreviations and symbols are used can be
converted to narrative form at field headquarters. If recording and transcribing
facilities are available, the narrative can be dictated from the field notes and
typed in block form. After narrative descriptions have been transcribed by a
typist or keyed into a computer and printed, the soil scientist should check the
accuracy of the descriptions.
Block Descriptions of Pedons
Comparisons among soils and within a pedon are most easily made from columnar
descriptions that use standard symbols and abbreviations. The descriptions
usually give dominant color, texture, mottling, structure, consistence, roots,
pores, additional features, reaction, and horizon boundary. Conventions for
describing each of these are given in chapter 3.
Columns of symbols and abbreviations are used mainly by soil scientist or
researchers, but they can be understood by others who are familiar with
narrative descriptions of typical pedons, pedons sampled for special studies,
and pedons that help in defining taxa. Abbreviations and symbols used in
descriptions will need to be converted to words. A standard format for narrative
soil descriptions is the “block description” (see typical pedon of Sharpsburg
series in Appendix II).
Maps and References
The selection of a mapping base for a soil survey is discussed in
chapter 4.
Some reference maps that also are useful in conducting a soil survey are
mentioned. Much geographic information pertinent to soil survey work is
available on maps published by various public and private organizations. Maps
dealing with climate have been prepared in the past by the Weather Bureau and,
more recently, by its successor in the National Oceanic and Atmospheric
Administration. Maps showing surface geology and bedrock geology are prepared by
U.S. Geological Survey, State geological surveys, and various other State
agencies, including some universities. Topographic maps are available for most
areas; some have overprints showing patterns of vegetation. For some areas, maps
showing vegetation, land use, and long-range zoning or land-use planning are
available.
Many reference maps are large and should be filed without folding. A plan
file or map file large enough to accommodate them can be purchased or
improvised. A simple file made from hardboard or plywood is adequate. The file
should have a systematic index so that maps can be found readily.
The soil survey field sheets can normally be stored in a letter file.
Atlas-size sheets need legal-size or larger files. Individual aerial photographs
can be filed by flights which can be separated by file indexes. The index map to
field sheets is a part of this file. Some care is required in filing and
handling completed field sheets to avoid cracking the photographic emulsion or
abrading the inked boundaries and symbols. The file and the completed field
sheets should be protected from fire, loss, and theft. Field sheets can be
photographed as soon as they are completed. The prints or negatives should be
stored where a fire cannot destroy both the reproduction and the originals.
During a soil survey, a substantial number of references are accumulated. One
of the first activities of the survey party is assembling a list of available
reference material about the survey area and its soils. This list is updated
during the survey. Some of the documents are kept in the soil survey office;
others are available only in libraries. Documents that are generated during a
survey also become references. By the time of final preparation of the
manuscript for publication, a substantial amount of reference material will have
been accumulated and should be readily accessible.
Literature databases, covering virtually every field of science and
technology, are available through the National Agriculture Library and
commercial information systems. Bibliographies can be prepared from the
databases for specific research problems, or general bibliographies can be
prepared for several subjects in a selected geographic area. A data base is
searched through an interactive computer terminal connected by telephone to the
information system computer. Using selected search terms and codes, the operator
examines the entire data base, selects data sets and narrows them from general
to specific. The retrieved citations can be printed on-line, which is faster for
short lists, or off-line, which is more economical for long lists.
Photographs
Photographs can illustrate important things about a soil in soil survey
reports, scientific journals, textbooks, and periodicals. Color transparencies
are ideal for slide presentations and color publications. Good photographs
provide records and reference sources of basic soils information. It is
necessary to plan early in the soil survey to begin taking photographs.
Photographs that include a scale are useful in estimating volume, area, or
size distribution. The comparison of coarse fragments in a soil against
photographs of known quantities of coarse fragments improves the reliability of
estimates. Similar photographic standards can be used to estimate volume or size
of nodules and concretions, mottles, roots, pores, and rock fragments. In like
manner, photographic standards can be used in estimating area or the special
arrangement of surface features and land use.
Equipment for field use.—Cameras suitable for soil survey documentation
include the 35-mm single-lens reflex, the 2 1/4 twin-lens reflex, and the 4x5
“press” camera. Self-developing cameras have proved very useful for recording
and documenting information for immediate and future reference.
A tripod is necessary, especially at shutter speeds below 1/50 second. Use of
a tripod reduces camera movement and enables the photographer to concentrate on
composition and focus. A flash is necessary in some poorly lighted situations or
to eliminate shadows.
Certain other items of field equipment are necessary for good pictures of
soil profiles. A scale to indicate depth or thickness is important. A scale that
does not contrast greatly with the soil, such as an unvarnished and unpainted
wood rule or a brown or khaki cloth tape, 5 cm by 1.5 m, can be used
effectively. Large black or yellow figures at 50-cm intervals, large ticks at
10-cm intervals, and small ticks at 5-cm intervals complete the scale.
A small spatula, kitchen fork, or narrow-bladed knife is useful for dressing
the soil profile. Paint brushes of various widths and a tire pump aid in
cleaning dust from peds. A sprayer can be used to moisten the profile when
necessary.
Photographing soil profiles.—Careful planning is essential for obtaining
high-quality photographs of soil profiles. A representative site is selected on
a road cut or borrow-pit face or in an area where a pit can be dug large enough
for adequate lighting of all horizons and for the camera to be 1 1/2 to 2 1/2 m
from the profile. The pit or cut face should be oriented so that when the
picture is taken the maximum amount of light will strike the prepared face at
the proper angle.
The profile will need to be properly prepared to bring out significant
contrast in structure and color between the soil horizons. Beginning at the top,
fragments of the soil can be broken off with a spatula, kitchen fork, or small
knife to eliminate digging marks. Dust and small fragments can be brushed or
blown away. Moistening the whole profile or part of it with a hand sprayer is
helpful in obtaining uniform moisture content and contrast.
Every profile should be photographed three or four times with different
aperture settings, angles of light, or exposure times. Notes should be made
immediately after each photograph is taken to record location and date, complete
description of the subject, time of day, amount and angle of light, camera
setting, method of preparing the profile, and other facts that will not show in
the photograph. Besides adding to the way the photograph can be used, good notes
provide information for improving technique. If possible take a landscape
photograph to accompany the soil profile photograph.
Photographing landscapes.—Landscape photographs illustrate important
relationships between soils and geomorphology, vegetation, and management. They
should be clear, be in sharp focus, and have good contrast. Needless to say,
photographs that are representative of the area being mapped are the most
useful.
The most important thing in landscape photography is lighting. The best
pictures are made at a time of day and during the time of year when the sun
lights the scene from the side. The shadows created by this lighting separate
parts of the landscape and give the picture depth. Photographs taken at midday
or with direct front lighting lack tonal gradation and, therefore, appear flat.
Photographs taken on overcast days are unsatisfactory for the same reason. A
small enough aperture should be used to gain maximum depth of focus.
A good photograph has one primary point of interest. Objects that clutter the
photograph—utility poles, poorly maintained roads and fences, signs, vehicles,
and personal items placed to show scale—detract from the main point. The point
of interest should not be in the center of the photograph. The “rule of thirds”
for composition is used by looking at the scene through the viewfinder and
visualizing the image area divided into thirds both horizontally and vertically.
The center of interest is placed at one of the four points where these lines
intersect. The image should contain no more than one-third sky, and the camera
must be kept level with the horizon.
Photographs should be taken from a variety of angles—from a kneeling
position, on a ladder, on top of a car or low building.
Close-up photography.—Many soil features such as peds, pores, roots, rock
fragments, krotovinas, mottles, concretions, and organisms can be photographed
at close range.
The minimum focusing distance for most cameras used in the field is such that
small features can be photographed. Short distances require a much smaller
aperture setting and, consequently, a slower shutter speed to ensure adequate
depth of focus.
Macrolenses are available for 35-mm cameras. These lenses permit focusing as
close as about 4 inches. They usually have a focal length of 50 to 55 mm and can
be used for general photography as well. Close-up attachments for conventional
lenses are available.
As with landscape photography, the lighting angle is important in close work.
Direct front lighting tends to blend texture, separation, and contrast in the
photograph.
Photographing clay films and other minute soil features requires special
equipment and techniques of photomicrography that are outside the range of this
manual.
Filing and care of negatives and prints.—A file system similar to that used
for field notes is helpful. Most photographs taken in support of a soil survey
can be related to a taxonomic unit or map unit and filed by series. A subject
card file with cross-references permits the greatest use of photographs with the
least effort. Photographic files should be organized in the same way as files of
notes. Negatives can be filed with each print in individual envelopes for
protection. Card files of an appropriate size with dividers are satisfactory for
storage.
Color 35-mm transparencies can be filed in clear vinyl pages, 22 cm by 28 cm,
with pockets for individual slides. These pages are kept in 3-ring binders
appropriately divided. Pages can be held to a light source for a quick search of
the file. All photographs and negatives should be kept in a cool area that is
isolated from chemicals and cleaning materials.
Automated Data Processing (ADP)
A large amount of many kinds of data are collected on a soil survey. How to
handle accumulated data to make full use of them always is a problem. A powerful
tool for dealing with this problem is ADP using computers and word processing,
data base, and spread sheet programs. ADP makes possible timely summaries,
comparisons, and analyses that otherwise would be impractical or impossible. It
enables frequent and inexpensive updating of long lists, such as lists of soil
series for States, regions, or the entire Nation, in any order or sequence. Such
summaries can provide information to guide important policy decisions. ADP can
quickly perform routine, time-consuming computations. It allows for easy editing
of descriptive materials, manuscripts, and so forth.
ADP is now widely used in soil survey and its use is expected to increase
greatly. Soil scientists need to know the fundamentals of ADP just as they need
to know the fundamentals of chemistry, botany, geology, mathematics, economics,
and other subjects that support the work of soil survey. Literature on the
fundamentals of ADP is readily available. Automated data processing can be used
for many soil survey tasks, but this is not to say that it should be used for
all of them. Before any decision is made to use ADP, an objective study—systems
analysis—is needed to determine what combination of equipment, personnel, and
other factors will be the most useful and economical. Any new system to be used
must take into account the compatibility with systems used by cooperating
agencies to handle soil survey data and related physical and environmental data.
Many combinations of computers, storage media, input-output devices, and
communications facilities are possible.
Even after an ADP system has been designed and implemented, study continues.
ADP technology is changing rapidly, and new equipment and new procedures are
appearing constantly. As experience is gained, an existing system may need to be
improved or replaced.
Automated data processing can manipulate data in many ways. Because most of
the data are likely to be needed in different combinations, the basic use is
likely to be data storage and retrieval. Such a use requires that precisely and
consistently defined records be entered into some medium readable by computers
and arranged in cataloged files. These files of soil records are a soil survey
data bank. Data banks can be kept at more than one location, depending on needs
and facilities. Also, soils data can be entered into banks at more than one
location. A uniform coding system is essential so that the data in the banks
will have a consistent format. A uniform coding system permits direct transfer
and sharing of data and the computer programs used to manipulate the data.
After the soils information has been systematically entered into the data
bank and the necessary equipment and operating instructions have been organized,
the data are available for many kinds or operations. Computer programs
(software) must be developed if they do not already exist. Software development
is usually the most expensive and time-consuming aspect of data processing. A
good data management system can reduce the amount of software needed. Some
examples of the important applications for soil survey are:
- Questions can be answered: What soils have certain sets of properties?
What soils are mapped in specified localities? What soils will produce corn
yields of more than 100 bushels per acre under a particular management system?
- Statistical studies, particularly multiple correlations, can be made for
many purposes. These include: testing the numerical limits of values in Soil
Taxonomy, determining what soil properties observable in the field correlate
well with laboratory results, and determining what observable soil properties
reliably indicate soil behavior.
- Summaries can be prepared by ADP—summaries of interpretations by soil
families, or phase of soil families, subgroups, and so on; summaries of the
acreage of kinds of soil in States, drainage basins, or other geographic areas;
and summaries of the number and area of soils having selected features, such as
a fragipan.
- Tabular material can be arranged and printed out for soil survey
manuscripts and other reports. Text that is repeated in published surveys of a
given State or region can be stored in finished form.
- Lists, such as the classification of soil series, can be stored and easily
updated.
- Interpretative maps can be printed on demand. This is likely to become an
increasingly valuable application for soil management and land-use planning.
Additional examples could be cited. As experience with ADP is gained, many
additional applications will become apparent. Users of ADP outputs must be aware
of the importance of reliable and accurate original information. High-quality
data must be entered in the first place; ADP cannot improve the quality of the
data.
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