1.7.1.4. Laterite Soil

Laterite has been derived from the Latin word ‘later’ which means brick. The laterite soil develops under tropical and subtropical climate with alternate wet and dry season. This soil is the result of intense leaching due to heavy rain.

Laterite soil is a type of soil that forms in tropical and subtropical regions. The name 'laterite' comes from the Latin word for brick, suggesting that this soil can be quite hard and brick-like. This soil is created from a process called leaching, where heavy rainfall washes away nutrients and minerals, leading to acidic soil that is often low in nutrients. The alternating wet and dry seasons contribute to its formation.

Think of laterite soil like the mud bricks used in many buildings. Just like how rain can wash away dirt and nutrients from the ground, it turns the soil into a brick-like substance. If you’ve ever seen or touched a mud brick, you can think of laterite as a natural version formed by nature’s processes.

Lateritic soils are mostly deep to very deep, acidic (pH<6.0), generally deficient in plant nutrients and occur mostly in southern states, Western Ghats region of Maharashtra, Odisha, some parts of West Bengal and North-east regions.

Laterite soil tends to be deep and can vary in acidity, typically having a pH level below 6, indicating that it is acidic. This kind of soil lacks many of the nutrients that plants need to grow well, making it less fertile compared to other soil types. It is commonly found in the southern parts of India, particularly in regions like the Western Ghats, Maharashtra, Odisha, and parts of West Bengal and the northeast.

Imagine a garden where you want to grow vegetables. If the soil is rich and nutrient-dense, you can expect to see lots of healthy plants. Now, picture instead a garden with sandy, dry soil that doesn't retain moisture or nutrients. That’s similar to laterite soil; it may not support a lush garden because it doesn’t have the nutrients needed for plants to thrive.

Where these soils support deciduous and evergreen forests, it is humus rich, but under sparse vegetation and in semi-arid environment, it is generally humus poor. They are prone to erosion and degradation due to their position on the landscape.

Laterite soil supports various kinds of vegetation, particularly deciduous and evergreen forests where it is found in areas that can retain more organic matter (humus). However, in regions with less vegetation, such as semi-arid areas, the soil can become poor in humus, which is vital for soil health. Additionally, because of how laterite soil is situated on the landscape, it can be easily eroded and degrade over time, especially during heavy rainfall.

Think of laterite soil like a sponge. When it's in a rich environment, it can hold onto water and nutrients, nurturing plants like a sponge keeps water. But if it’s left exposed to harsh conditions or if plants are not present, it can dry out and crumble, just like a sponge that's been left in the sun and loses its elasticity.

After adopting appropriate soil conservation techniques particularly in the hilly areas of Karnataka, Kerala and Tamil Nadu, this soil is very useful for growing tea and coffee. Red laterite soils in Tamil Nadu, Andhra Pradesh and Kerala are more suitable for crops like cashew nut.

With specific soil conservation methods, laterite soil can become productive for growing certain crops, especially in hilly regions. In states like Karnataka, Kerala, and Tamil Nadu, this type of soil can be beneficial for crops like tea and coffee, which thrive in well-drained, acidic soils. Additionally, the red laterite found in Tamil Nadu and parts of Kerala and Andhra Pradesh is particularly suitable for cultivating cashew nuts.

Imagine a gardener who learns how to rejuvenate worn-out soil by adding compost and using cover crops. After applying these techniques, the garden begins to flourish. Similarly, farmers can enhance laterite soil's productivity with the right methods, ensuring that crops with specific needs, like coffee and tea, can flourish in areas where they might not have thrived previously.

--