Laterite soil is rich in aluminium and iron, formed in wet and hot tropical areas. Almost all laterite soils are red due to the presence of iron oxides. It is prepared by the prolonged and rigorous weathering of the parent rock. Laterisation or tropical weathering is a long-drawn-out process of chemical and mechanical weathering which results in a large variety in the chemistry, grade, thickness and ore mineralogy of the ensuing soils. Laterite soils are deficient in potash, phosphoric acid, lime and nitrogen.
Concentration of Laterite Soil in India
Laterite soil in India is mainly found capping the flat uplands, and is also spread in the western coastal region, getting incredibly heavy rain. Lateritic soils are also abundant in area along the edge of the plateau in the east, covering small parts of the states of Tamil Nadu and Odisha and a small portion of the Chota Nagpur Plateau in the north and Meghalaya in north-east. Laterite soils are habitually poor and can hold only scrub forests and pastures. Among the mixed types of soils, two groups are more substantial. They include the desert soils of western Rajasthan and mountain soils of the Himalayas.
Laterite soils are found on the high level plateau and hilly areas that receive high rainfall and are specifically well developed on the Eastern Ghats in Odisha. It is found in the southern regions of the Western Ghats including the adjoining coastal regions in Ratnagiri District and Malabar, Rajmahal hill, Maharashtra, Kerala, Karnataka, West Bengal, Assam, Andhra Pradesh etc. Laterite soil is also widely found around the Satpura, Vindhyan Plateau, Maikal and Mahadeo ranges in Madhya Pradesh.
Characteristics of Laterite Soil
Laterite soil is primarily found in the tropical regions which receive heavy seasonal rainfall. High rainfall encourages the leaching of soil where lime and silica are leached away and a soil rich in oxides of aluminium predominate and abundance laterite is called bauxite. Due to the presence of iron oxides the colour of laterite soil is basically red. This soil is poor in lime content and hence it is acidic.
Humus is almost absent in this type of soil. However, in the laterite soil developed in the forested areas in the western part of Karnataka state, humus is present. Further, laterite soils of high level areas are very poor and least retentive of moisture and at times barren. But, in the low lying areas, regular addition of soils that are washed down from the adjacent higher areas affects lateritisation. In those areas, the lateritic soil being either mud or loam is useful and is regularly ploughed. For the continuous cultivation of crops, regular application of fertilizers is required.
Cultivation in Laterite Soil
Although initially deficient in fertility due to leaching, this unique soil type has proven to be remarkably useful for a range of agricultural pursuits, as well as non-agricultural applications.
Agriculturally, laterite soil demonstrates its potential in supporting the growth of various crops. Rubber, wheat, rice, pulses, and coconut farming find a conducive environment in this soil type. For specific crops, laterite soil showcases exceptional compatibility. The practice of effective soil conservation techniques, particularly in the hilly regions of Kerala, Karnataka, and Tamil Nadu, has enabled successful coffee and tea cultivation. In Andhra Pradesh, Tamil Nadu, and Kerala, laterite soil has proven advantageous for cashew nut production. It`s important to note, however, that while these regions capitalize on the advantages of laterite soil, its suitability extends primarily to dryland crops.
A diverse range of crops thrives within the parameters of laterite soil. Arecanut, banana, various vegetables, tapioca, yams, pineapple, pepper, and fruit trees are among the entities that flourish in this distinctive soil type. This expansive variety attests to the adaptability of laterite soil in accommodating a plethora of cultivation endeavors.
Other Uses of Laterite Soil
Laterite soil, celebrated for its role in agriculture when appropriately enriched with dung and sand, unfolds an array of alternative uses that extend beyond the realm of farming. Notably, both laterite and its derivative, lateritic soil, emerge as exceptional construction materials, showcasing their versatility and significance in various contexts.
In construction, this soil readily lends itself to be hewn into standardized blocks using a simple shovel, particularly when it is damp. Extracted from areas beneath sea level in their soft and moist state, laterite soil undergoes a transformation upon exposure to air. The moisture trapped between its flattened clay granules gradually dissipates, rendering the soil firmer and more compact. This unique attribute transforms laterite into a formidable construction material that stands resilient against the elements.
Moreover, the elevated iron content inherent to laterite soil enhances its potential applications. This iron-rich composition makes laterite soil an optimal candidate for brick production. This additional utility underscores the resourcefulness and adaptability of laterite, showcasing its potential to serve multifaceted purposes.
