AG 308: History of Soil Survey in the Philippines

• AG 308 covers Soil Survey, Classification, and Use and is taught by Arman Q. Egos at Negros Oriental State University, Pamplona Extension.

Brief History of Soil Survey in the Philippines

• 1903 marked the first attempt at a soil survey in the Philippines, conducted in Batangas province.
• Clarence Wilbur Dorsey, an American soil scientist, led the first soil survey in the Philippines and wrote "Soil conditions in the Philippines”.
• In 1921, the Division of Soils and Fertilizers was established under the Bureau of Science.
• Dr. Angel S. Arguelles (1888–1952) became chief of the division in 1923 and pioneered the study of "The Soils of the Islands of Luzon”.
• 1934 saw the beginning of an actual soil inventory in the country through the Soil Survey Committee, organized by the Secretary of Agriculture and Commerce.
• In 1936, the Bureau of Science reorganized the Division of Soils and Fertilizers into the Division of Soil Survey.
• The National Assembly enacted Commonwealth Act 416 in 1939, tasking the Division of Soil with agronomical soil surveys.
• In 1948, the Soil Survey Division was reorganized into the Division of Soil Survey and Conservation.
• June 5, 1951, Congress established the Bureau of Soil Conservation with five divisions, under R.A. 622.
• Dr. Marcos M. Alicante was the first Director of the Bureau of Soil Conservation.
• In 1936, the first Bureau director was an experienced soil surveyor, having conducted soil surveys of Bulacan, Batangas, Pampanga, Pangasinan, Tarlac, and Nueva Ecija from 1938 to 1941.
• Ricardo T. Marfori (1960–1965) wrote "The Fertilizer Requirements of Rice in the Philippines" and was an expert on tropical soil fertility.
• Atanacio A. Simon (1966–1971) was a soil surveyor involved in projects in Batanes and Samar before leading the Bureau.
• Reconnaissance soil surveys of all 75 provinces in the Philippines were completed in the 1960s.
• Juan A. Mariano served as the Bureau director from 1971 to 1976.
• Godofredo N. Alcasid, Jr., was the longest-serving director, from 1976 until his retirement in 1996.
• On January 30, 1987, President Aquino reorganized the Bureau of Soils into the Bureau of Soils and Water Management (BSWM) through EO 116.

Soil Survey Principles and Organization

• Soil survey, as defined by USDA-NRCS, is the systematic examination, description, classification, and mapping of soils.
• Soil survey involves describing soil characteristics, classifying soils by a standard system, mapping soil boundaries, and predicting soil behavior.
• General purpose surveys provide a basis for various interpretations and involve creating a pedological map.
• Special purpose soil surveys are for known and specific purposes, best used where much is already known about the area.
• Agricultural technicians, farmers, researchers, foresters, planning agencies, NGOs, engineers, and private investors are users of soil surveys.
• Land use planning, land management, and land appraisal are the uses of a soil survey.
• Applications include planning and management for agro-forestry, engineering, and special purposes like urban planning and waste disposal.
• A soil survey must have a purpose, and a soil map must show soils.
• Land resources include but are not limited to soils.
• The soil map and report are complementary.
• Soil survey is only an aid, not the sole basis for land use decisions.
• Limitations include difficulty mapping soils to high accuracy, creating a universally useful map legend, and grading land uniquely from "best" to "poorest".
• Soil surveys alone cannot accurately estimate crop yields or predict consequences of certain land uses.

Key Identifying Kinds of Soil Surveys

• 1st order surveys: Soil identification by traversing or transecting delineations. Minimum delineation size: 1 hectare or less. Typical map components include phases of soil series and miscellaneous areas. Map units are mostly consociations, complexes, and miscellaneous areas. Appropriate field mapping scales are 0.6 1:15,840 or larger.
• 2nd order surveys: Soil identification by field observations and remotely sensed data. Minimum delineation size: 0.6 to 4 hectares. Map components include phases of soil series and miscellaneous areas. Map units are consociations and complexes. Appropriate field mapping scales are 1:12,000 to 1:31,680.
• 3rd order surveys: Soil plotted by observation and interpretation data. Minimum delineation size: 1.6 to 16 hectares. Map units are mostly associations or complexes. Appropriate field mapping scales are 1:20,000 to 1:63,360.
• 4th order surveys: Soil plotted by remotely sensed data interpretation. Minimum delineation size: 16 to 252 hectares. Map units are mostly associations and consociations. Appropriate field mapping scales are 1:63,360 to 1:250,000.
• 5th order surveys: The soil patterns and composition determined by mapping. Minimum delineation size: 252 to 4,000 hectares. Form associations and some consociations. Appropriate field mapping scales are 1:250,000 to 1:1,000,000.

Types of Soil Surveys

• 1st Order: Experimental plots for houses; Very Detailed Planning. Common name of survey: Very Detailed. Very intensive planning for appraisal of small areas.
• 2nd Order: Farming and urban development; Detailed planning. Common name of survey: Detailed. Provides information for local planning.
• 3rd Order: Ranching and watershed management; Reconnaissance-General specialized planning. Common name of survey: Reconnaissance. Gives information at the level of farming areas.
• 4th Order: Large watersheds; Broad Reconnaissance. Common name of survey: Broad Reconnaissance. Provides information for large agricultural areas or regional plans.
• 5th Order: Multi-state or nations; General very broad planning. Common name of survey: Exploratory. Gives general information for regional/provincial plans.

Types of Maps

• Soil Map: Shows the geographical distribution of various soils.
• Soil Survey Map: A soil map made from field information.
• Interpretation Map: Compiled for a specific purpose using soil map information.
• Single Factor Map: Depicts one feature derived from a soil map and can be called extractive maps.
• Generalized Soil Map: Developed from more detailed, published soil information.
• Schematic Map: An interpretive "best guess" map, based on supplementary information.
• Exploratory Map: It differs negligibly from schematic maps and contains about the same level of information but is based on some actual field observations.

Kinds of Maps Based on Detail

• Reconnaissance Maps: Based on observations and data from study region traverses and known elements of formation factors.
• Semi-Detailed Maps: Use traditional procedures, corresponding to one observation per cm2.
• Detailed Maps: Result of highly precise studies. A minimum of one observation per cm2 is given.

Types of Maps Based on Scale

• Small Scale Maps (1:1,000,000 or smaller): Permit general interpretations and geographical study of soils.
• Medium Scale Maps (1:50,000 or 1:100,000): Used for regional planning and prospective work.
• Large Scale Maps (larger than 1:50,000): Permit practical applications for local development planning.

Maps based on objectives

• Pedological Maps
• Regional Planning Maps
• Maps of agronomic application

Types of Map Units

• Consociation: A soil mapping unit dominated by a single taxon.
• Association: Soil mapping unit with two or more defined taxonomic units, not separated due to survey objectives.
• Complex: Soil mapping unit in detailed surveys where units are intermixed geographically, deemed impractical to separate.
• Undifferentiated: Mapping unit with two or more soils mapped together, lacking a regular pattern due to an overriding factor.

Other Significant Terms in Soil Survey

• Soil Series: Basic unit of soil taxonomy, consisting of soils with similar profile characteristics.
• Soil Type: Formerly a subdivision of soil series based on texture differences in the A horizon.
• Soil Variant: A soil with distinct properties but in a small area, not warranting a new series creation.
• Soil Phase: A subdivision of a soil series with characteristics affecting use/management, but not enough for a separate series.
• Landscape: Natural features that distinguish one part of the earth's surface from another. It contains specific patterns of flora, fauna, and soils.

Checklist for Survey Planning

• Objectives: Identification and definition, including location, problems, time, and finance.
• Environment: Appraisal of biophysical and social aspects like climate, geology, topography, and previous surveys.
• Survey Design: includes Publication scale, mapping scale, observation intensity, use of remote sensing and automatic data handling and laboratory requirements.
• Soil Classification and Map Legend: Using US Soil Taxonomy, FAO - UNESCO Soil Map.
• Interpretation - land evaluation activities and legend.
• Availability and Sustainability of topographical and base Commissions.
• Scheduling: Staff mobilization, field research, API, tests, interpretation, field checks, report, and submission.
• Staffing: Project leader, professional, and support staff.
• Logistics: Establishing a survey field base, accommodation, travel, transport, equipment, materials, and laboratory facilities.
• Publication: includes Publication form, printing method, and number of copies.

Sequence of Survey Operations

• Initial Reconnaissance: Identifying major problems, establishing work methods, and familiarizing the team.
• Main Survey: Establishing distribution of land units.
• Sampling: Sampling major mapped areas for characterization.
• Consolidation: "Filling-in" complex areas or testing mapped areas.
• Reporting: Creating the final report and accompanying maps/diagrams.

Soil Profile Description

• Soil description includes a description of the soil surface horizons in the profile.
• Rock Outcrops, for example, can range from 'None' at 0% cover to 'Dominant' at >80% cover.

Mapping using GIS

• GIS is used for preparing terrain mapping unit (TMU) maps that integrate data and satellite images to derive information.
• GIS also integrates it with land cover/use.
• GIS methods lead to time savings. Also, improvements in data quality can be achieved.

Soil Classification

• The USDA Soil Taxonomy is a detailed soil classification system developed by the Soil Survey Staff of the U.S. Department of Agriculture along with other scientists.
• Pedon is the smallest sampling unit of soil.
• The criteria for differentiating soil in Soil Taxonomy at various levels in the classification are soil-forming processes and horizons.
• The categories of Soil Taxonomy include Order (12), Suborder (63), Great Group (250), Subgroup (1,400), Family (8,000), and Series (19,000 in U.S. only).
• To classify soils in Soil Taxonomy, determine the diagnostic horizons and the soil moisture and soil temperature regime.
• Diagnostic horizons are indicative of soil classes.
• SMR (Soil Moisture Regime) is the presence or absence of water saturation.
• STR (Soil Temperature Regime) is the mean annual soil temperature at 50 cm.
• Epipedons are diagnostic horizons at the surface.
• Subsurface diagnostic horizons occur usually in the B horizon or the subsurface.
• Mollic horizon: thick, dark, high organic C, high base saturation, strong structure.
• Umbric horizon: similar to mollic, except it has low base saturation.
• Ochric horizon: thin, light-colored, low OM, hard and massive when dry.
• Melanic horizon: thick, black, high in OM and short-range order minerals.
• Histic horizon: thick, very high OM, usually water-saturated.
• Folistic horizon: thick, high OM, usually not saturated with water.
• Anthropic horizon: a human-modified mollic-like horizon with elevated phosphorus levels.
• Plaggen horizon: human-made sod-like horizon created by long-term manuring.
• Subsurface diagnostic horizons are generally below the A horizon.
• Albic horizon: light-colored from the removal of clay.
• Argillic horizon: illuvial accumulation of silicate clay.
• Natric horizon: like argillic, but high in sodium.
• Spodic horizon: organic matter, Al, and Fe precipitates in the subsoil and is associated with spodosols.
• Cambic horizon: shows soil alteration and structure.
• Agric horizon: OM and clay accumulation from cultivation.
• Oxic horizon: highly weathered; mixture of Fe and associated with oxisols.
• Calcic horizon: secondary accumulation of CaCo3, common in arid areas.
• Kandic horizon: high accumulation of low-activity clays associated with ultisols and oxisols.
• Soil Temperature Regimes: Listed from hot to cold - Hyperthermic, Thermic, Mesic, Frigid, Cryic, or Pergelic.
• Soil Moisture Regimes: Listed from dry to wet - Aridic, Xeric, Ustic, Udic, or Aquic.