Land capability classification and land suitability evaluation Flashcards
LAND CAPABILITY CLASSIFICATION(LCC)
system of grouping soils primarily on the basis of their capability to produce common cultivated crops and pasture plants ▪Shows the suitability of soils for most kinds of crop ▪soils are grouped according to their limitations for field crops, the risk of damage if they are used for crops, and the way they respond to management ▪grading of soils according to potential and limitation, capacity for producing agricultural crops.
Importance of land capability classification
induces a systematic segregation of various land types
provides a scientific method for conservation of land and proper land use planning
tools for land use planners
helps in minimizing land degradation
Capability classes
broadest groups, are designated by the numbers. The numbers indicate
progressively greater limitations and narrower choices for practical use.
Class I: soils have slight limitations that restrict their use.
Class II: soils have moderate limitations that restrict the choice of plants or that require moderate conservation practices.
Class III: soils have severe limitations that restrict the choice of plants or
that require special conservation practices, or both.
Class IV: soils have very severe limitations that restrict the choice of plants or that require very careful management, or both.
Class V: soils are subject to little or no erosion but have other limitations, impractical to remove, that restrict their use mainly to pasture, rangeland, forestland, or wildlife habitat.
Class VI: soils have severe limitations that make them generally unsuitable for cultivation and that restrict their use mainly to pasture, rangeland, forestland, or wildlife habitat
Class VII: soils have very severe limitations that make them unsuitable for cultivation and that restrict their use mainly to grazing, forestland, or wildlife habitat.
Class VIII: soils and miscellaneous areas have limitations that preclude commercial plant production and that restrict their use to recreational purposes, wildlife habitat, watershed, or esthetic purposes.
Capability sub-classes
are soil groups within one class. They are designated by adding a small letter, e, w, s, or c, to the class numeral, for example, IIe.
e - shows that the main hazard is the risk of erosion
c - shows that the chief limitation is climate that is very cold or very dry
w - shows that water in or on the soil interferes with plant growth or cultivation
s - shows that the soil is limited mainly because it is shallow, droughty, or stony
Note: In class I, there are no sub-classes because the soils of this class have few limitations.
Capability units
More specific and detailed information on soil groups within a subclass
Grouping of soils alike in suitability for plant growth and response to soil
management
Capability units are generally designated by adding an Arabic numeral to the subclass symbol, for example, IIe-4 and IIIe-6
1.All the LCC systems are based on the………….
1.Principle of Limiting Factor
Physical factors include:
Altitude
Slope
Erodibility
Soil depth
Rainfall
Topsoil stones
Subsoil stones
Drainage
Soil pH
Challenges to land capability classification
Rugged Terrain
Limited land holding
Limited human and institutional capacities
Limited available resources
Land Suitability Evaluation
is the fitness of a given land type for a defined use
assessment of land performance when used for a specified purpose
involves the execution and interpretation of surveys and studies of land forms, soils, vegetation, climate and other aspects of land
Guided by the objectives of the evaluation
LAND SUITABILITY ORDERS
Land suitability Orders indicate whether land is assessed as suitable or
not suitable for the use under consideration.
There are two orders represented by the symbols S and N respectively
a.Order S - Suitable-Land on which sustained use of the kind under
consideration is expected to yield benefits which justify the inputs, without unacceptable risk of damage to land resources
b.Order N - Not Suitable
-Land which has qualities that appear to preclude sustained use of the kind under consideration.
Land Suitability Classes
reflect degrees of suitability
classes are numbered consecutively, by arabic numbers, in sequence of
decreasing degrees of suitability within the Order
Classes under Order Suitable
Class S1 Highly Suitable:Land having no significant limitations to sustained application of a given use, or only minor limitations
Class S2 Moderately Suitable-Land having limitations which in aggregate are moderately severe for sustained application of a given use; although still attractive, will be appreciably inferior to that expected on Class S1 land.
Class S3 Marginally Suitable:Land having limitations which in aggregate are severe for sustained application of a given use and will so reduce productivity or benefits, or increase required inputs.
Classes under Order Not Suitable
Class N1 Currently Not Suitable-Land having limitations which may be surmountable in time but which cannot be corrected with existing knowledge at currently acceptable cost
Class N2 Permanently Not Suitable-Land having limitations which appear so severe as to preclude any possibilities Of successful sustained use of the land in the given manner.
