Indigenous Knowledge and Development Monitor, 1993

SOIL SURVEYS AND INDIGENOUS SOIL CLASSIFICATION - Joseph A. Tabor

Farmers and herders all over the world have developed land classification systems which can provide useful insights into their farming and land tenure systems. These classification systems also offer a useful vehicle for talking with villagers about agricultural and land tenure issues. Anthropologists and geographers for some time have documented that these systems exist. More recently, soil scientists have used them to guide soil surveys.

The most difficult task in conducting a soil survey is creating a good soil legend that effectively separates soils on their productive capacity and that allows easy identification in the field. By interviewing farmers and herders on their systems of soil classification, soil scientists can
(1) rapidly identify all the soils that are important to the farmer;
(2) determine each soil's relative productivity and their value to agriculture; and
(3) locate typical soils of each type and correlate them to other systems, both scientific and indigenous.

Land classification systems that are developed by farmers separate soils by characteristics important to the farmer. Soil scientists tend to be biased toward classification systems they know and thus commonly separate soils to fit the division breaks of their own system. This practice can overly complicate the soil survey, or worse, disregard separations that are important to the farmer. Local systems can provide clues for identifying those soil characteristics that are most limiting to land management and can help the soil scientist identify agricultural interventions that will most economically improve the soil's productivity.

Common vocabulary

Local land tenure relationships are more easily understood by outsiders if they know the local systems of land classifications. This knowledge also provides outsiders with a common vocabulary to discuss land tenure issues with farmers and herders, as well as allowing interviewers to quickly determine the resource base and wealth of farmers and villages. Needless disruption in tenure relationships can be avoided if local land classification systems are integrated into a development project's soil and cadastral survey.

Many of the soils described by farmers in developing countries fit within the concept of soil series and they have a wealth of information on these soils, including their relative productivity. In some cases, farmers make finer distinctions than would normally be made in a conventional soil series. For example, Soninke farmers in drought-prone Senegal, Mauritania, and Mali, make very fine distinctions between soils with respect to their period and frequency of flooding.

Local soil names and the knowledge farmers possess for each soil are extremely useful but they have their imprecisions, especially if one tries to regionalize local names. Farmers know their local soils well, but the soil names that are used are not always correlated between farmers or regions. Throughout Haiti, for example, farmers give soils names like 'red' and 'sandy' to reflect their color and texture, or terms such as 'depression' that reflect the nature of the associated landscape. However, other soil names represent specific soils and seem well correlated, even across language groups.

Complementary

Indigenous soil classification systems should be viewed as complementary to scientifically-based systems and integral to soil mapping. Indigenous systems have an advantage in that they are widely known by the people of the region and can easily improve communication between farmers, extension agents and scientists. Relatively few scientists, technicians, and extension agents need to learn the farmer's classification system.

Recent publications in this area include Roman Pawluk, Jonathan Sandor and Joseph Tabor, 'The role of indigenous soil Knowledge in agricultural development', Journal of Soil and Water Conservation, 1992, vol. 47, no. 4, pp. 298-302; and D. Michael Warren, A preliminary analysis of indigenous soil classification and management systems in four ecozones of Nigeria, 1992, Ibadan: African Resource Centre for Indigenous Knowledge and the International Institute of Tropical Agriculture.

Joseph A. Tabor Office of Arid Lands Studies University of Arizona Tucson, Arizona 85719 USA

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