LCC

LAND CAPABILITY CLASSIFICATION

LAND CAPABILITY CLASSIFICATION 

Land capability classification is the grouping of land units into defined classes based on their capability. Evaluation of land for land use planning is a consequent step following soil survey and mapping process. The capability of land units depends on their limitations and it is designed to emphasize on the hazards in different kinds of soils. It serves as a guide to assess the suitability of different land units for arable crops, grazing / forestry. This system however, maynot be suitable for intensively cultivated plain areas, such as Indo Gangetic plain (in India)

Depending on the nutritional and other properties soils behave differently. Some are suitable for cultivated crops, others for pastures and still others may be suitable only for forestry (or) recreation.

The grouping of soil units into capability classes and sub classes is done on the basis of their capability to produce crops and pasture biomass without adversely affecting the productivity over a long period of time. The criteria used for assessing a land unit are the physical land properties and the degree of limitation with which crop growth is inhibited. It is mainly based on

1.Inherent soil properties

2.External land features

3.Environmental factors that limit land use (climate vegetative)

The first two information can be derived from a standard soil survey report and the third information is collected from other agencies (or) sources.

The factors determining the capability of a soil

• Depth of soils stoniness, rockiness

• Texture and structure of soil

• Permeability (Movement of air and water through the soil)

• Relief (as expressed by slope)

• Extent of erosion

• Susceptibility to over flow, flooding and degree of wetness.

• Presence of toxic salts, alkali and other unfavourable chemical properties such as pH, gypsum salts, aluminium etc.

Climatic variation (in respect of soil temperature and moisture regimes)

The capability classification does not suggest the most profitable use of land. Further, these grouping are subject to changes as new information about the soils and their response become available. 

The capability classification consists of three categories namely

1.Capability classes

2.Capability sub-classes and

3.Capability units

Capability classes

         Eight capability classes are recognized. The soils having greatest capability for response to management and least limitat6ions are grouped in class – I and those having least. Capability and greatest limitations are grouped in class-VIII. Each capability class is correlated with the cropping system as conditioned by LGP.

Land capability classifications (Eight classes)

Land suitable for cultivation                                                                                                                                     

Land capability class

       Class I                     Very good land (No limitation)

Class II                     Good land (Minor limitation)

Class III                    Moderately good (major limitation)

Class IV                    Fairly good (major limitation with occasional cultivation)

Land not suitable for cultivation

Suitable for pasture and grazing             -      Class VIII

suitable for wild life and recreation          -    Class V (No limitation),Class VI (Minor limitation),Class VII (Minor Limitation)

Brief description / salient features of LCC

Name of the class                    -                class – I            

Colour shown on LCC             -                Green     

Salient features                        -                Excellent cultivable deep, nearly level. Productive land with no limitation (or       very slight hazard)

Crop suitability crops              -                Suitable for most crops like wheat, barley, cotton, maize tomato and beat

 Management                             -     Need no management practices for cultivation

Name of the class                     -               Class – II

Colour shown on LCC              -               Yellow

Salient features                          -               Good cultivable land on almost level plain or on gentle slopes limitation of soil depth, salinity, texture, drainage / erosion that reduces the choice of plants

Crop suitability crops                -                Suitable for wheat, barley, cotton

Moderately suitable for maize, alfalfa, tomato

Slightly suitable for beans

 Management                                -                 Cultivate with precaution need simple management practices.

Name of the class                         -               Class III

Colour shown on LCC                  -               Brown

Salient features                              -              Moderately good cultivable land on almost level plain or on moderate slope. Limitation :L Moderate erosion soil depth, soil salinity and soil texture. They may have vertic characteristics (or) drainage problem that reduces the choice of crops

Crop suitability crops                      -           Unsuitable for growing vegetable crops. Varying suitability for different crops

Management                                      -          Cultivation with careful management practices need intensive care.

Name of the class                             -             Class IV

Colour shown on LCC                      -            Pink

Salient features                                 -           Fairly good land on almost level plains or moderately steep slopes

Limitation                                           -          Strong / very strong soil salinity S3/S4 shallow soil depth, strong erosion, fine soil texture. Poor (or) excessive drainage.

Crop suitability crops                        -         Limited cultivation unsuitable for growing a variety of crops. Suitable for selected crops 8 for pasture. Not economical to cultivate

Management                                        -       Need intensive soil conservation and management practices

Name of the class                               -                  Class V

Colour shown on LCC                        -                 Dark grey

Limitations                                           -                Story, rocky nature (or) marshy-ness use of implements is difficult

Management                                        -               Not suitable for arable farming suitable for grazing

Name of the class                                       -             Class VI

Colour shown on LCC                                -           Orange

Salient features                                           -            Moderate limitation such as steep slope severe erosion, limiting soil depth, strongly gypsiferous, stony or sandy (sand – dune areas) eg. dense forest lands of the Himalays. Sandy (gypsiferous) and donal areas of Thar Desert in Rajasthan and SW Irag.

Management                                                 -          Non-arable land well suited for grazing (or) forestry

Name of the class                                          -            Class VII

Colour shown on LCC                                   -            Red

Salient features                                              -           Severe limitation such as steeply sloping land subjected to erosion (or) very shallow stony soils that have not enough moisture

Management                                                    -           Fairly well suited for grazing or forestry but not cultivable.Need careful management for grazing and forestry

Name of the class                                              -        Class VIII

Colour shown on LCC                                       -        Purple

Salient features                                                  -       Severe limitation

Very steeply sloping, highly eroded, rocky barren mountain landscape, hyper arid rocky undulating surface

Management                                                       -        Non-arable, suitable for wildlife (or) recreation. Extremely rough, rocky, arid, wet (or)  extremely saline land

Capability subclasses

         The capability subclasses are based on kinds of dominant  such as wetness or excess water (w), Climate (C), soil (S) and erosion (e).  The subclasses are mapped by adding limitation symbols to the capability class number subscripts for example II e, IIIw etc.  Therefore the subclasses indicate both the degree and kind of limitations.  The capability  subclasses provide information as to the kind of conservation problems or limitations involved.  There are no sub-classes in capability class-I land, since there is no limitation in this class.

Capability units :

         A capability unit includes soils which are sufficiently uniform in their characteristics, potential and limitations and require fairly uniform conservation treatment and management practices.

         If the existing limitations can be permanently removed (or) reduced in extent by proper conservation measures (or) management practices, such as provision of irrigation, drainage, control  of gullies and construction of flood – retarding irrigation structures, then the land capability class can be changed towards a better class.  A further deterioration in the existing conditions will shift the capability to a worse class.

FERTILITY CABAPILITY CLASSIFICATION

The Fertility Capability Soil Classification (FCC) was developed by Buol, Sanchez and co-workers (Buol, 1972; Buol et aI, 1975, Sanchez et aI, 1982) as a technical system for grouping soils according to the kind of problems they present for agronomic management of their chemical and physical properties. The system emphasizes quantifiable topsoil parameters as well as subsoil properties directly relevant to plant growth and yield performance. The FCC System (quoted from Sanchez et al 1982) The system consists of three categorical levels: type (topsoil texture), substrata type (subsoil texture), and 15 modifiers, including several changes from the original version (Buol et al, 1975) making the following, in effect the second approximation. The classes within each categorical level are defined below. Class designations from the three categorical levels are combined to form an FCC-unit.

Type

Texture of plow-layer or surface 20 cm, whichever is shallower: 

S = sandy topsoils: loamy sands and sands (by USDA definition) ;

L = loamy topsoils: <35% clay but not loamy sand or sand;

C = clayed topsoils: > 35% clay;

o = organic soils: >30% O.M. to a depth of 50 cm or more.

Substrata type (texture of subsoil)

Used only if there is a marked textural change for the surface, of if a hard root restricting layer is encountered within 50 cm:

S = sandy subsoil: texture as in type;

L = loamy subsoil: texture as in type;

C = clayey subsoil: texture as in type;

R = rock or other hard root-restricting layer.

Modifiers

Where more than one criterion is listed for each modifier, only one needs to be met. The criterion listed first is the most desirable one and should be used if data are available. Subsequent criteria are presented for use where data are limited.

• g = (gley); soil or mottles <2 chroma within 60 cm of the soil surface and below all A horizons, or soil saturated with water for >60 days in most years;

• d = (dry): ustic, aridic or xeric soil moisture regimes (subsoil dry >90 cumulative days per year within 20-60 cm depth) ;

• e = (low cation exchange capacity): applies only to plow layer or surface 20 cm, whichever is shallower: CEC <meq./100 g soil by E bases + KCI-extractable Al (effective CEC) , or CEC <7 meq./100 g soil by E cations at pH 7, or CEC <10 Meq./100 g soil by E cations + Al H at pH 8.2;

• a = (aluminum-toxicity): >60% AI-saturation of the effective CEC within 50 cm of the soil surface, or >67% acidity saturation of CEC by E cations at pH 7 within 50 cm of the soil surface, or >86% acidity

• saturation of CEC by E cations at pH 8.2 within 50 cm of the soil surface, or pH 5.0 in 1:1 H20 within 50 cm, except in organic soils where pH must be less than 4.7

• h = (acid): 10-60% AI-saturation of the effective CEC within 50 cm of soil surface, or pH in 1:1 H20 between 5.0 and 6.0%;

• i = (high p-fixation by iron): % free Fe2 03/% clay> 0.15 and more than 35% clay, or hues of 7.5 YR or redder and granular structure. This modifier is used only in clay (C) types; it applies only to plow-layer or surface 20 cm of soil surface, whichever is shallower

• x = X-ray amorphous): pH> 10 1n 1N NaF, or positive to field Naf test, or other indirect evidences of allophone dominance in the clay fraction;

• v = (vertisol): very sticky plastic clay: > 35% clay and >50% of 2:1 expanding clays, or severe topsoil shrinking and swelling:

• k = (low K reserves): <10% weatherable minerals in silt and sand fraction within 50 cm of the soil surface, or exchangeable K <0.20 meq./100 g, or K <2% of E bases; if bases < 10 meq./100 g;

• b = (basic reaction): free CaC03 within 50 cm of the soil surface (effervescence with HCI) , or pH> 7.3;

• s = (salinity): > 4 dS/m of electrical conductivity of saturated extract at 25°C within 1 m of the soil surface;

• n = (natric): > 15% Na-saturation of CEC within 50 cm of the soil surface;

• c = (cat clay): pH in 1:1 H20 is < 3.5 after drying, and jarosite mottles with hues of 2.5 Y or yellower and chromas 6 or more are present within 60 cm of the soil surface;

• g = (gravel): a prime (I) denotes 15-35% gravel or coarser (> 2 mm) particles by volume to any type or substrata type texture (example: S'L = gravelly,sand over loamy; SL' = sandy over gravelly loam); two prime marks(") denote more than 35% gravel or coarser particles (> 2 mm) by volume in any type or substrata type (example: LC" = loamy over clayey skeletal; L'C" = gravelly loam over clayey skeletal);

• % = (slope): where it is desirable to show slope with the FCC, the slope range percentage can be placed in parentheses after the last condition modifier (example: Sb (0-8%) = uniformly sandy soil calcareous in reaction, 0-8% slope).

The soils are classified by determining whether the characteristic is present or not. Most of the quantitative limits are criteria present in the Legend of the Soil Map of the World (FAO/Unesco, 1974).