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Historical summary of soil-related activities in Thailand

Year 1935

(B.E. 2478)

          Soil survey and classification started in Thailand since before the World War II. Dr. Robert L. Pendleton – an American soil scientist coming to Thailand around the year 1935 as an advisor of the Ministry of Agriculture – was  the pioneer in such discipline along with a Thai technician, Dr. Sarot Montrakun (a soil scientist from the Philippines who later naturalized to be a Thai national) as his close colleague. At that time the transportation system in the country was not convenient, so the soil survey could specifically be carried out for only some places. Identification of the boundary of each soil type had to rely on the geology map (surface rocks) and forestry map (types of trees).

          However, there was a publication of the “Provisional Map of Soils and Surface Rocks of the Kingdom of Thailand” by Robert L. Pendleton with a scale of 1:2,500,000, in 1949. There were 21 units of soil types, e.g. Lopburi clays, Khorat fine sandy loan and Chiangmai loam, etc.


          After Dr. Pendleton passed away, Dr. Sarot Montrakun and his party continued the soil survey to improve the soil map of Thailand to be more correct whereby the project was assisted by the United States Operations Mission (USOM) and “The Provisional Soils Map of the Kingdom of Thailand by Robert. L. Pendleton and Sarot Montrakun” was published for distribution in 1960.


          Dr. F.R. Moormann, a Dutch expert of the United Nation’s Food and Agriculture Organization (FAO), started to work in Thailand as a soil survey expert in 1961. He cooperated with Thai soil scientists of the Rice Department and Department of Agriculture of the Ministry of Agriculture, namely, Dr. Sarot Montrakun and Dr. Saman Phanichaphong, in studying and improving the soil map of Thailand from the soil map made by Dr. R.L. Pendleton, and they started to survey and make soil map emphasizing at first in the Northeastern region and some parts of the Central region.


          In 1963, the government under Field Marshal Sarit Thanarat, The Ministry of National Development was established (est. 23 May 1963), with the Land Development Department (LDD) as one of its several departments. The LDD had got transferred the functional tasks and related units concerning the survey and classification of land from various departments of the Ministry of Agriculture and from the Department of Lands of the Ministry of the Interior. At that early stage the LDD consisted of four main divisions, namely, Soil Survey, Land Classification, Land Conservation, and Land Policy Divisions.

          The Government of Thailand and international organizations including USOM (later changed the name to the United States Agency for International Development: USAID) and FAO had fully given support to the soil survey tasks and soil map production in all aspects including the budget, instruments, technical experts and gave scholarships to the Department’s staff to pursue their studies in foreign countries. It has been regarded as the period of development on the soil survey, land classification and soil map production in Thailand to have a quality comparable with those produced in developed countries.

          The foreign experts and Thai technical counterparts who had important roles in that period were Dr. F.R.  Moormann, Dr. Robinson (an American), Mr. F. Steele, Mr. D.C. Schwaar, Mr. F.J. Dent (a British scientist), Mr. J.J. Shoten, Mr. Van der Kevie (a Dutchman), Mr. Ying Wacharakupt, Dr. Saman Phanichaphong, Mr. Chaliaw Jaengphrai, Mr. Thamrong Charasai, Mr. Banjong Yenmanat, Mr. Wichai Bunyawat, Mr. Suraphon Charoenphong, Mrs. Nuansri Kanchanakul, Dr. Pisoot Vijarnsorn, Mr. Pramote Hemsrichat, Mr. Phichai Wichaidit, and Emeritus Professor Dr. Santhad Rojanasoonthon.

          The soil survey and classification was firstly emphasized in the Northeastern part, Central part and the upper Northern part whereby the responsibility was divided into 10 zones according to their geographical conditions. In each year there would be meetings, seminars, training courses, field visits regularly and continuously as well as the production of many technical documents and soil survey reports in both English and Thai.


          The staff of the Land Development Department, Dr. F.R. Moormann and Dr. Santhad Rojanasoonthon of Kasetsart University had jointly improved the new soil map of Thailand by applying the soil classification system that Dr. R. Dudal and Dr. F.R. Moormann had improved with some information from the soil classification system of the United States Department of Agriculture ( USDA, 1938 ) to add, to suit the soil condition in various countries in Southeast Asian region and had The Kingdom of Thailand General Soil Map printed for distribution at 1:1,250,000 and 1:2,500,000  scales. The great soil group and the combined unit of two or more great soil groups in the same perimeter were used as the soil map unit. Thailand had used this soil classification system as the national soil classification system for a period and it appears in many old soil survey reports and soil maps published by the Land Development Department.


          Soil scientists of Thailand started to adopt the Soil Taxonomy, which was the new classification system of the USDA, and had experimented by the previous soil classification system of Thailand. The Department later considered it suitable to use as the soil classification system in Thailand; it then made amendments to name soils of upper categories to be more compatible with the new system. There was a new production of the soil characteristics description (series description) to be compatible with those applied by the USA and there was a production of a soil survey handbook so that the staff in soil survey teams will use for the soil survey and classification and soil map production for various regions of the country.

          The soil survey mission was expanded to produce provincial soil maps from the detailed reconnaissance soil survey in the Northern, Central and the Southern parts of Thailand and had the soil maps printed for distribution in 1:100,000 scale. Soil series and the mixed units of soil series comprising from two series upward were used as units of soil map.

          There was a soil map production in semi-detailed soil survey in the Great Chao Phraya Irrigation Project in the Central Plain, with soil maps of 1:50,000 scale. Levels and types of soil series were mainly used as the units of soil maps.


          The Coup d’Etat Administration led by Field Marshal Thanom Kittikhachorn dissolved the Ministry of National Development and transferred the LDD to be under the Ministry of Agriculture and Cooperatives. 


          The technical assistance from international organizations came to the end but the mission on soil survey and classification still continued under the supervision of Mr. Ying Vacharakupt and Dr. Saman Phanichaphong, whereby the mission continued in the provincial and project levels, with budget provided by the Government of Thailand.

          The number of staff expanded; the area of Thailand was divided into eight survey zones, with approximately 36 persons for each zone (during 1973-1977) to survey and produce soil maps in various projects including (1) the project for soil survey in each province with targeted areas in various parts of the country, (2) the project for soil survey along both sides of highways all over the country, (3) the project to survey vacant lands in the Northeastern part, as well as (4) soil survey projects required by state agencies such as the soil survey project in the area to relocate people affected by inundation due to the Ban Chao Nen Dam, Kanchanaburi; the royal initiative project at Nong Phlap Sub-district , Prachuap Khiri Khan Province; Highland Development Project of USOM, Chiang Mai Province; the soil survey at the site to establish the Acid Sulfate Soils Research Center, Ongkharak District, Nakhon Nayok Province; and Ba Jo and Mu No Drainage Projects in Narathiwat Province, etc.


          Series of conferences and training courses were organized on soil classification with Soil Taxonomy system in a systematic way so that the soil survey and classification could be implemented correctly, up-to-date and complying with the international standard.

          Soil survey work in that period was divided into 12 zones, each zone consisting of 6 soil survey teams and each team with 5-6 staff working closely with the soil classification standard units. The detailed reconnaissance survey (การสำรวจดินแบบค่อนข้างหยาบ) and the semi-detailed survey (การสำรวจดินแบบค่อนข้างละเอียด) were conducted at provincial and project levels, with the production of soil maps of 1:50,000 and 1:100,000 scales. Such works were considered efficient, with good standard according to the international system and were accepted widely.


          Dr. Pisoot Vijarnsorn and Mr. Chingchai Jongphakdee had improved the soil maps of Thailand by using Soil Taxonomy system and produced the General Soil Map of Thailand at 1:1,000,000 scale and regional soil maps at 1:500,000 scale. The great group, accompanied by the particle-size classes, was used as the soil map unit to display (1) the soil texture characteristics and clay and (2) gravel or rock over 2 mm particle-size contents in the soil profile at 25-100 cm depth. Both soil maps were widely used for various projects, especially as basic data to plan for land use at regional and national levels.


          The provincial soil survey (detailed-reconnaissance) was completely done for all over the country.

          Soil survey at farm level shifted to the provinces to be under the responsibility of the Soil Survey, Classification and Land Use Planning Section of the 12 Land Development Regional Offices, with the duty to make detailed survey and very detailed survey for the area not larger than 10,000 rai (1,600 ha), and to produce 1:10,000 scale maps or larger to use in the land use planning and soil and water conservation at farm level. The soil survey officers of the Soil Survey and Classification Division in Bangkok, however, were responsible for the soil survey and soil map production for the project with area larger than 10,000 rai; the emphasis was for the semi-detailed survey and for the production of 1:50,000 scale soil maps or larger to use in land use planning in the district level and to use in land development projects that require more detailed information on soil resources than for the provincial level, or any specific project as requested by other agencies.

          The pilot project on semi-detailed soil survey at district level started, with purpose to serve for the area development planning in the district level or smaller.

1987 - 1991

          A project to improve the 1:50,000 scale provincial soil maps was implemented, to produce a report of land use for economic crop cultivation in each province with the soil series group as map unit. There were 62 soil series groups in total, consisting of 59 groups and 3 other units that were combined soil units according to the topographic condition. All 62 soil series groups came from the combination of soil types in the soil series classification according to the Soil Taxonomy system related to the similarity in physical and chemical characteristics with potential in having similar land use in the same group. That is for the convenience in data application for extension purpose or for land use planning to suit the potential of the land. Also included were the data displaying the soil suitability classes for economic crop cultivation in each province according to the kinds of crops expected to give favourable cost-effective return.


          The semi-detailed soil survey at district level started. The 1:25,000 soil maps displaying data with soil boundary on mosaic aerial maps or A3 plagues – so called “Photo mosaic” – were produced. The map unit is the soil series or ‘soil phase’ which is at an even lower level than soil series that affects the land use and management, such as slope, topsoil texture, soil depth, soil erosion as principal features. Included were the information on soil suitability classes for growing important economic crops and the guidelines for basic land management.


          Dr. Pisoot Vijarnsorn and the party produced a new series of soil maps of Thailand by improving the map units of the 1:1,000,000 scale General Soil Maps of Thailand (published in 1979) to comply with the Soil Taxonomy system of 1992 to present at the exhibition part in the 15th World Congress of Soil Science at Mexico (Vijarnsorn et al., 1994).


          The Land Development Department and Multiple Cropping Center of Chiangmai University jointly developed the digital soil database system by using the geographic information system (GIS) and produced CD-ROMs for soil database program and land use suitability for each province. That was the first information technology (IT) work of the Land Development Department.


          Development of the IT program to retrieve data from soil series and the suitability of soil that suits economic crops, generally known as ‘SoilView’ program.


          Soil data were improved and soil maps for each province were produced; they can display the soil boundary on the topographic maps of the Royal Thai Survey Department. Soil series, soil type and soil association were used as map units. Maps of 1:50,000 scale were produced for 12 provinces, namely, Chiang Mai, Lamphun, Phrae, Uttaradit, Nakhon Ratchasima, Khon Kaen, Kalasin, Maha Sarakham, Roi Et, Buriram, Ubon Ratchathani and Narathiwat.


          To reform the bureaucratic system of the LDD, the ‘soil survey and classification’ and ‘land use planning’ tasks were combined to become the Office of Soil Survey and Land Use Planning.

          The Land Development Department had developed SoilView 2.0 program further that was more complete and more convenient to users, and there was a retrieving system to use for land resource management and to support other agricultural development endeavors from additional digital soil series database, including AgZone, LandPlan, ConsPlan, LandSuit and SoilMan.

          The Land Development Department was the principal host of the 17th World Soil Congress in Bangkok.


          Soil maps of Chiang Mai, Lamphun and Buriram provinces were improved and the “Soil Maps and Reports on the Study of Soil Resources and Land Potential in Provincial Level” with the semi-detailed 1:25,000 scale soil maps were produced. Soil series, soil phase and soil association were used as map units. Besides having corrected and improved soil data in various areas to match their actual conditions at present, there was also a refined division of soil boundaries to be more distinct, so that they could be used for land use planning at the district and sub-district levels.


          The improvement and development of the semi-detailed soil maps for provincial level all over the country started by applying the orthophoto (แผนที่ภาพถ่ายออร์โธสีเชิงเลข) in combination with the examination and adjustment of the soil boundary in the field. The 1:25,000 scale maps and report on soil survey for agricultural implementation in each province, with soil series group as the map unit, were produced. This mission was completely executed all over the country in 2010.


          A project to study the main representative soils for economic development of the country started, with purpose to determine the characteristics of the main representative soils including studying the environment that affects the formation of soil, morphology, chemical and physical properties and soil micromorphology.


          At present, it is time to assess the need to improve the provincial soil resources data of 1:25,000 scale maps to be more accurate, by using soil series and soil types as map units. Besides, there is also continuance of the project on the study of the main representative soils in soil series level for agricultural development of the country. There is a collection of environmental data that affect the soil formation and a collection of soil samples to analyze for the detailed characteristics and properties, including morphological, physical, chemical, mineralogical and micromorphic properties; all of which will be brought to the analysis to improve the soil resources database to be used for many purposes in the future.  

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