Soils of Kerala

Soils of Kerala
Soils of Kerala
Based on the physio-chemical properties, the soils of Kerala can be classified into 10 different broad groups. These are

Coastal Alluvium
This type of soil is found along the coastal belt of the state. It is the result of recent marine deposits and has little traces of fluvial sediment. It has high sand content, low water holding capacity and is slightly acidic in reaction (less than ph 6.5). Its texture varies from loamy sand to sandy loam.

Riverine Alluvium
This type of soil is mainly found along the river valleys across the state. Its texture varies from sandy loam to clay and known for high water holding capacity and high nutrients content. It supports the cultivation of Paddy, Arecanut, Pepper, Tapioca and a variety of vegetables.

Red Loam
It is found in isolated patches near the foothills of the Sahaya Mountains in the parts of Thiruvananthapuram and Neyyattinkara. It is deep red in colour due to the presence of hematite and limonite ores and acidic in nature (pH 4.8-5.9). Additionally, it is low in available nutrients and only supports crops like Coconut and Tapioca.

Laterite Soil
This type of soil is scattered throughout the state occupying 58% of the total area. This soil is formed as the result of intensive and prolonged weathering of the underlying parent rock under humid tropical conditions. Its colour varies from reddish brown to yellowish red and texture ranges from gravelly loam to gravelly clay loam. It is acidic in reaction (pH 4.3.) and poor in available nutrients, but it is well drained and can support a variety of crops like Aracanut, Cashew, Coconut, Pepper, Tapioca and Rubber with the proper application of fertilizers and irrigation.

Greyish Onattukara soil
This type of soil is found in the Onattukara region which comprises parts of Alapuzha and Kollam. It has distinctive grey colour and its texture varies from coarse grained sandy loam to pure sand. It is slightly acidic (pH 6.2) and low in nutrients. Moreover, it has low water retention capacity. However, with application of proper farming techniques, one can cultivate crops like Paddy, Tapioca and Coconut on this soil.

Acid Saline soil (Kuttanad Alluvium)
This type of soil is mainly found in Kuttanad region. As a large portion of Kuttanad lies below the sea level, it faces some hydrographical problem such as flooding and salinity, which put limitations to farming practices. However, with careful management, one can successfully grow Paddy and other crops on this soil. The Kuttanad Alluvium is further subdivided into 3 categories on the basis of morphological and physiochemical properties. These are 1. Kayal soil (soil in reclaimed areas with high clay content), 2. Kari soil (black soil with high organic content) and 3. Karappadam soil (soil with high silt content).

Brown hydromorphic soil
This type of soil is mainly found in the wetlands. They are moderately rich in organic matter and other nutrients, but deficient in lime and phosphate. It is deep brownish in colour and its texture varies from sandy loam to clay. It is also acidic in reaction with ph value of 5.2 pH. It is formed due to the transportation and deposition of soil from adjoining hill slopes. It suffer from impeded drainage and exhibits hydromorphic features like grey horizons, streaks, hard pans and organic matter deposition.

Hydromorphic saline soils
This type of soil is found near the coastal tracts of the State. Their salinity is the direct result of the intrusion of backwaters and tidal waters into these areas. These soils are brownish in colour and their texture varies from sandy to clayey. They support salt resistant crop varieties such as Pokkali and Kaipad rice.

Black Soils
The black soils are mainly found in the north eastern part of Palakkad district. It is dark in colour, low in organic matter, calcareous, moderately alkaline (pH 8.0) and high in clay content. As this soil promotes cotton cultivation, it is also known by the name of black cotton soil. Other major crop that can be grown on this soil are Rice, Sugarcane, Jowar, Ragi and Oil Seeds.

Forest loam soils
This type of soil is found in the eastern part of the State. Its colour varies from dark reddish brown to black and texture varies from loamy to silty loam. It is rich in organic matter, but acidic in reaction (pH of 5.8), which makes it poor in bases. It supports plantation crops like Cardomom, Rubber and Tea.

Source: Department of Agriculture, Kerala