Definition, Objectives/Uses, and Types of Soil Survey
Definition of Soil survey
Soil survey is a systematic study of the soil of an area including classification and mapping of the properties and the distribution of various soil units.
Soil survey is essentially a study of soil morphology in the field. Soil survey includes classification of soils of the area in well-defined units, characterization of soil properties, plotting their extent and boundaries on a map and predication of the adaptability of these soils to various uses.
Objectives and Uses of Soil Survey
The main objective is to get information about the soil genesis and provide information about the soils resources of the area. Therefore, it forms basis for planned land use and resource management.
Soil survey information may be useful in farm planning, which include land uses, cropping system, application of manures and fertilizers, tillage practices, water management. The information may be utilized for other purposes such as reclamation of problem soils, development of grass and forestry, wildlife protection planning for irrigation and drainage, construction of road, rail track etc.
Types of Soil Survey
Surveys are (a) Detailed survey (b) Reconnaissance survey, and (c) Detailed-reconnaissance survey.
(a) Detailed Survey
Elaborate mapping is done, demarcating the lowest categories of taxonomic and mapping units, viz., type and phases —which are genetically quite homogeneous.
(b) Reconnaissance Survey
The mapping is less elaborate and larger areas are surveyed rapidly. Such surveys provide broad undertaking of soils and are particularly useful in new and relatively undeveloped regions for general planning. Reconnaissance survey fairly serve the purpose in areas of lesser importance such as in mountainous regions.
(c) Detailed-Reconnaissance Survey
They constitute elements of both detailed and reconnaissance surveys. The regions of better use potentialities are surveyed in detail while reconnaissance surveys are made in regions of low potentialities.
Soil Survey Methods
They primarily concern the studying of soil profiles in the field as well as in the laboratory; mapping soils according to well-defined legends; collecting all relevant information about the climate, physiography, hydrology, geology, vegetation, present land use; scientific data about recommended practices and their responses; socio-economic conditions of the area; and preparing soil survey reports and soil maps.