9.7. Land Degradation

The pressure on agricultural land increases not only due to the limited availability but also by deterioration of quality of agricultural land. Soil erosion, waterlogging, salinisation and alkalinisation of land lead to land degradation.

Land degradation refers to the decline in the quality and productivity of land. This can occur for various reasons, including limited availability of land and its degradation due to natural processes like soil erosion or human activities such as overuse or poor agricultural practices. Erosion can wash away the fertile topsoil, while waterlogging occurs when the land becomes saturated with water, making it unproductive. Salinisation is the accumulation of salts in the soil, which can be harmful to plant growth, whereas alkalinisation refers to increased soil alkalinity, which can also reduce agricultural viability.

Imagine a garden where you planted flowers. If it rains too much and the soil becomes muddy, your plants might drown, just like how waterlogging harms the land. Similarly, if you keep growing the same plants without adding nutrients or rotating crops, the soil's nutrients can get depleted, making it hard for anything to grow, similar to how we need a balanced diet to stay healthy.

What happens if land is consistently used without managing its fertility? Land is degraded and productivity declines. Land degradation is generally understood either as a temporary or a permanent decline in productive capacity of the land.

If agricultural land is exploited without proper management of its fertility, it may lead to a decline in productivity. This can happen in two ways: temporarily, such as after over-farming during a single season, or permanently, due to ongoing neglect and poor agricultural practices that would destroy the land's ability to produce crops. The consequences can be economic, affecting farmers' incomes and food supply, and environmental, leading to loss of biodiversity and ecosystem function.

Think of a rechargeable battery. If you keep using it without charging it, it will eventually stop working. Similarly, if farmers don’t replenish the soil nutrients, the land will become tired and stop producing healthy crops, much like that dead battery.

There are two processes that induce land degradation. These are natural and created by human beings. National Remote Sensing Centre (NRSC) has classified wastelands by using remote sensing techniques and it is possible to categorise these wastelands according to the processes that have created them.

Land degradation can occur through natural processes, such as drought or flooding, and can also be accelerated by human activity, such as deforestation or overgrazing. The NRSC uses remote sensing technology to observe and categorize different types of wastelands based on how they were degraded. Understanding whether land is degraded by natural causes or human actions is crucial for developing appropriate restoration strategies.

Consider a forest area. If a storm knocks down trees, that’s a natural cause of degradation. But if people cut down trees to build homes, that’s a human cause. By analyzing satellite images, scientists can identify which areas need attention, just like a doctor diagnosing who needs treatment based on symptoms.

Though all degraded land may not be wasteland, but unchecked process of degradation may lead to the conversion to wasteland. There are a few types of wastelands such as gullied /ravinous land, desertic or coastal sands, barren rocky areas, steep sloping land, and glacial areas, which are primarily caused by natural agents.

Not all land degradation results in wasteland, but continued degradation often leads to permanent loss of land productivity, eventually resulting in wasteland. Different types of wastelands exist, for example, gullied land which is characterized by deep trenches caused by erosion, desertic areas which are dry and barren, and steep sloping land that is prone to erosion. These types can emerge from both natural factors like climate and human factors like land misuse.

Imagine a sandcastle on the beach. If left alone, it might wash away with the waves—that’s nature acting. But if you keep stepping on it, it collapses faster. Similarly, if land is constantly misused, it can turn into wasteland far quicker than if it was just left alone.

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