ADVERTISEMENTS:
Land use capability classification indicates the suitability of various kinds of soil for economic uses, mainly agriculture.
The classification devised for Indian conditions draws heavily from the classificatory approach followed by the United States Department of Agriculture. The guiding principles for this classification are the limitations imposed on the sustained use of soils by the basic characteristics of soils in combination with climate, topography,” surface drainage, vegetation cover, erodibility and other natural hazards.
ADVERTISEMENTS:
There are eight land capability classes which are indicated by Roman numbers I to VIIL Then, there are capability sub-classes and capability units. The classes I to IV include lands suited for cultivation and should be maintained under natural vegetation of forests or grasses.
This scheme of land capability classification is based on economic returns in terms of agricultural output because agriculture is the most widespread and basic occupation in India.
The various classes and their characteristic features are as follows:
Class I:
Soils in this class are very good. The soils are deep, productive and easily worked and nearly level. They are not subject to overflow (runoff) damage. However, they are subject to variations of fertility and puddle erosion. Soils of this class have slight or no risk of damage. These are the most productive parts of our country and are to be found in flood-plain regions of the country.
Class-I soils used for crops need practices’ to maintain soil fertility and soil structure. These practices involve use of fertilisers, cover cropping, green manure crop and crop rotation.
ADVERTISEMENTS:
Class-II:
As far as natural conditions are concerned, the land is excellent, but some limitation is possible, which may restrict the choice of crops to some extent. Soils of this group can be cultivated with easily applied practices, and a majority of crops can be grown. They are, however, subject to moderate risk of damage.
Soils of this group have gentle slopes and are subject to moderate erosion. They are also subject to moderate overflows. These are areas of specialised cropping and are commercially one of the most suitable parts of our land.
These soils may require special practices, such as contour tillage, crop rotation and water-control devices.
Class III:
ADVERTISEMENTS:
These are moderately good soils. They can be used regularly for crops. These soils have steep slopes and suffer from either some ecological problem (as soil erosion) or climatic problem (rainfall irregularity) which inhibits intensive commercial exploitation. Also, these soils are inherently low in fertility.
These soils require cropping systems that produce adequate plant cover. The cover is needed to protect the soil from erosion. It also helps protect the soil structure. Also, proper surface drainage should be ensured and practices like contour tillage undertaken.
Class IV:
These soils are affected by severe permanent hazards like waterlogging and water deficiency. They occur frequently on steep slopes which are vulnerable to erosion. The soils are low in fertility. Commercial exploitation is nearly absent. Subsistence farming is practised and mainly coarse grains are grown on these soils.
These soils should be kept in pastures. A grain crops may be grown once in five or six years. Soil and. moisture conservation measures, like water disposal of terraces, contour tillage and stabilisation of gullies, should be undertaken.
Class V:
These soils are found in foothills or in mountain valleys and are suitable for grasses, shrubs, etc. These soils should be used for pasture or forestry operations. Cultivation is not feasible because these soils are wet and stony. The land is nearly level and subject only to slight erosion by wind or water, if properly managed. There are few permanent limitations. Grazing should be regulated in these soils.
Class VI:
These soils have moderate permanent limitations and are unsuitable, for cultivation. These soils should be used for grazing and forestry. They are steep and shallow and more prone to erosion than class V soils. Grazing should not be permitted in these soils. They suffer from certain environmental constraints as well and are the environmentally fragile zones of our country.
Class VII:
The severity of environmental constraints is much greater in these soils, compared to class VI soils. As a result, these soils are subject to severe permanent hazards. They are fair to poor for grazing or forestry. These soils are steep, eroded, shallow or swampy and are completely unsuitable for cultivation. Strict management should be applied to these soils.
Class VIII:
These occur in those parts which have no direct potential for exploitation for living. These soils can serve the purposes of preserving some rare species or acting as a water catchment zone. Soils of this class are extremely rough, arid or swampy and are unsuitable for cultivation. They are not suited for forestry or grazing. They may be used for wildlife sanctuaries, recreation or watershed uses.
Capability Sub-Classes:
These are subdivisions of capability classes, made on the basis of four dominating limitations, namely, (i) risk of erosion (e), (ii) wetness, drainage or overflow (w), (iii) rooting zone limitations (s), and (iv) climatic limitations (c). The sub-classes are mapped by adding the limitation symbol to the capability class number, e.g., IIe, Ills, etc. There are no sub-classes in Class I.
Significance of Land Capability Classification in Landuse Planning:
ADVERTISEMENTS:
Land capability classification helps in planning for landuse:
1. The land capability classification determines the use ceiling for any piece of land and helps to define the conservation problems and possible treatments. Keeping this in mind, a piece of land can be put to the most efficient landuse. For instance, all agricultural activity must be confined to classes I to IV and others, such as pasturelands, energy plantation, buildings, roads, etc., to classes V to VIII. Within this scheme, one can select the most suitable crop for a particular piece of land.
2. The land capability classes can change towards better classes, if the existing limitations can be permanently removed or reduced in extent by economically feasible reclamation measures, such as providing irrigation, providing proper drainage, constructing flood-control measures or stabilising, gullies. A further deterioration of existing conditions can, on the other hand, shift the capability to poorer classes.