soil survey organization & planning determine the purpose of the survey, details required,...

Soil Survey Organization & PlanningSoil Survey Organization & Planning

Determine the purpose of the survey, details required, scale of final mapping, type of in-situ testing, number of deep boring, etc.

Critically examine the TOR to determine whether the proposed scale of mapping and SIL is adequate for preparing maps suitable for project’s intents.

Best Option and AlternativeBest Option and Alternative

It is best if soil surveyor is involved at the project inception to discuss and finalize the nature and intensity of the survey and the time requirements.

Most often, soil team is requested to perform survey long after project is planned. Alternatively, lead surveyor must adapt the survey to fit the time constraints.

Remember!Remember!Soil surveyor must inform the

project director and field teams what can and cannot be done in allotted time..

Failing to inform the project management of the limitations of survey at the onset of the job puts all the blame on your shoulders.

Background Data & Literature ReviewBackground Data & Literature Review

Aerial photography: availability, coverage, scale, date of photography.

Topographic map: availability, coverage, scale, contour intervals, date of issue.

Previous studies: Any previously prepared soil, land inventory, geomorphic description, etc in the area or in similar localities

Background Data & Literature ReviewBackground Data & Literature Review(cont.)(cont.)

Geologic maps and reports: useful in determining parent rocks and potential soil catenas, landscape characteristics, & potential soil mineralogy.

Crop and soil management data: If available, data on soil and crop management both within project or in areas with similar climate and soil types.

Planning and scheduling of workPlanning and scheduling of work To ensure on-time completion of work prepare a

bar chart with critical paths! Finalize and agree on density of soil

observation, depending on soil complexity and degree of difficulty.

Average observation density should be 1 in 4 ha in complex landscape (floodplains, recent alluvium, saline-sodic soils, etc) to 1 in 10 ha for average complexity (basin soils, plateau soils) and as low as 1 per 25 ha in area with simple soil-landscape complexity (older landscape, sedentary soils, loess soils).

Sequence of Soil Survey Sequence of Soil Survey ActivitiesActivities

Initial field reconnaissance. Research phase Mapping phase (main survey activities) Correlation and QC Interpretation phase (Report writing)

Initial field ReconnaissanceInitial field Reconnaissance

To identify major potential survey problems (preliminary identification of major soil-landform-vegetation relationships);

To check extent, location and quality of arable land and soil variability;

Determining intensity of observation to reach project objectives;

Establish the method of survey to be adopted.

Research PhaseResearch Phase

Determine which soil properties are most important for the purpose of survey.

Determine soil classes that should be mapped.

Establish the preliminary mapping legend and field relations between soil-landform-vegetation.

Mapping phaseMapping phase Auger-hole/profile description and soil sampling for

lab analyses. Relationship between soil-landscape-vegetation

should be finalized. Have some flexibility with original sampling plans

based on findings in the field. Establish, modify and evolve preliminary

classification and mapping units and test them to determine the needs for changes.

Describe soils to the lowest possible taxonomic level and establish rage of soil characteristics for dominant soils.

Main Field ActivitiesMain Field Activities Soil sampling:

• sample major mapped soils for detailed analyses;• Perform detailed in-situ soil physical tests; and• Deep boring (up to 5-6 m) for irrigation/drainage.

Consolidation of results:• “filling in” observation in areas with complex soils

where boundaries cannot easily be established;• Revision of initial API based on field findings,

analytical results, and development of final soil classification and mapping legend.

Correlation and QCCorrelation and QC

No two soil surveyors will have the same conceptual model therefore, their maps might not be exactly the same.

Correlation allows maintaining survey quality.

To ensure consistency and adherence to the standards established for the survey (provisional mapping legend).

Revise and improve the legend to ensure high quality of survey.

Correlation and QC (Cont.)Correlation and QC (Cont.) Check mapping unit purity, especially in

high intensity surveys. Stratified random transects sampling

method can be used for checking “purity”. If mapping unit purity is below standards,

additional field work is required. Location of boundaries can also be

checked by the same method, but detailed checking along soil boundaries is not practical.

Interpretation phase (report writing)Interpretation phase (report writing) Soil survey produces a voluminous amount

of data that needs interpretation. Data collected, including profile, auger-

hole, in-situ tests, lab results, and correlation studies should be compiled.

Supplementary API can be incorporated to develop revised (final) mapping legend and soil boundaries.

Prepare final report.

Things to Remember!Things to Remember!

Use soil exposures.Use flexible approach.Carefully plan fieldwork schedule.Check and report variability of

mapping units.Allow ample time for correlation

work

Things to Remember! (cont.)Things to Remember! (cont.)

Use standard notations.Observe crops and natural

vegetationDouble check survey areas and soil

boundaries in “public” places.Prepare duplicate (carbon copy)

data sheets

Checklist of Soil Survey OperationsChecklist of Soil Survey Operations

Operation Comment

1. Technical Procedures

Depth and intensity of auger hole/soil profile sampling

Establish depth for auger hole and soil profile description, location, and observation intensity, based on TOR and reconnaissance survey.

Soil sampling Decide on method and criteria for selection of sampling sites.

Soil Suitability/Land Evaluation

Decide on characteristics and quantitative limits to use in description and definition of each class


Operation Comment

1. Technical Procedures (cont.)

Mapping Decide on sizes, layout, and contents of base maps, and subjects and symbols for thematic details to be added (soil series, phases, and parameters).

Soil in-situ physical tests

Decide on types, method, numbers, and depths


Operation Comment

1. Technical Procedures (cont.)

Daily Routines Establish procedures such as (i) correction and correlation of field sheets (drainage classes, land evaluation units, etc), (ii) plotting obtained data on field maps (GWT depths, sampling points, soil boundaries), (iii) discussion of technical amendments and additions with team members.

Checklist of Soil Survey OperationsChecklist of Soil Survey OperationsOperation Comment

2. Administrative Procedures

Team Responsibilities

Assign responsibilities for specific technical admin. Operations to individuals, avoid overlap of authority.

Daily routines Establish departure and return times, drying, labeling and bagging samples, field sheet, photo and equipment preparation for the following day, field and office timetables, etc.

Logistic support Food, fuel and maintenance supplies, labor payment, local purchases, information flow to and from main office, etc.

Field Data RecordingField Data Recording Use standard data sheets for recording auger

hole and soil profile characteristics. Use standard and uniform soil description to

facilitate future cross-cutting and comparison between different soils in and outside the project area.

Use of FAO-ISRIC developed soil profile description (1990) and computerized soil database (1995) to record the soil and terrain data is strongly recommended.

Pay special attention to factors that have direct relevance to crop growth (landform, drainage, permeability, rooting system, etc.)

Soil Sampling ProceduresSoil Sampling Procedures

Judgment and random sampling Depth and intensity sampling Correlation sampling Composite sampling Undisturbed core sampling Duplicate sampling (5 to 10% of total)

Sample Prep., recording, shippingSample Prep., recording, shipping

Better to air-dry sample before shipping. Label each sample twice (tie-on, inside). Short and simple labels. Include project name on label. Lab register with date, site #, depth, and

duplicate number. Ask lab to keep sample for 6+ months. Minimum 1 kg dry soil for detailed and

150-200 g for restricted sample analysis.

Although labs are always on-time Although labs are always on-time and provide good data, you need and provide good data, you need to check on them periodically. to check on them periodically. Otherwise, the data may arrive Otherwise, the data may arrive after report is finalized! A non-after report is finalized! A non-acceptable procedure that is acceptable procedure that is sometimes followed. sometimes followed.